Williamson-Thermoflo GWS-090E User manual
Part Number 550-110-737/1108
Contents Page
1 Prepare boiler location .......................................................2
2 Prepare boiler.....................................................................8
3 Install water piping..............................................................9
4 Venting and combustion air..............................................12
5 Gas piping........................................................................12
6 Field wiring.......................................................................13
7 Start-up ............................................................................14
8 Checkout procedure.........................................................16
9 Sequence of operation.....................................................17
10 Operating instructions ......................................................19
11 Service and maintenance.................................................20
12 Troubleshooting................................................................25
13 Replacement parts...........................................................33
14 Dimensions.......................................................................38
15 Ratings.............................................................................39
Boiler Manual
GWS-
090
E
Gas-Fired Water Boiler
This manual must only be used by a qualified heating installer/service technician. Failure to comply could result in
severe personal injury, death or substantial property damage.
When calling or writing about the boiler— Please have: • boiler model number from the boiler rating label and
•CPnumberfromtheboilerjacket.YoumaylisttheCPnumberinthespaceprovidedonthe“Installationandservice
certificate” found on page 16.
Hazards that will or can cause minor personal
injury or property damage.
Special instructions on installation, operation or
maintenance that are important but not related to
personal injury or property damage.
INSTALLER —Read all instructions before
installing. Read page 2 first. Follow all instruc-
tions in proper order to prevent personal injury or
death.
• Considerpipingandinstallationwhendetermining
boiler location.
• Anyclaimsfordamageorshortageinshipment
must be filed immediately against the transporta-
tion company by the consignee.
USER — Please read the following. Failure to
comply could result in severe personal injury,
death or substantial property damage.
• This manual is for use only by your qualified
heating installer/service technician.
• PleaseseetheUser’sInformationManualforyour
reference.
• Have the boiler serviced by a qualied service
technician, at least annually.
Hazards that will cause severe personal injury,
death or substantial property damage.
Hazards that can cause severe personal injury,
death or substantial property damage.
Hazard definitions
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
2Part Number 550-110-737/1108
Codes & checklist
When servicing boiler —
1. To avoid electric shock, disconnect electrical supply
before performing maintenance.
2. To avoid severe burns, allow boiler to cool before per-
forming maintenance.
Boiler operation —
3. Do not block flow of combustion or ventilation air to
boiler.
4. Shouldoverheatingoccurorgassupplyfailtoshutoff,do
not turn off or disconnect electrical supply to circulator.
Instead, shut off the gas supply at a location external to
the appliance.
5. Do not use this boiler if any part has been under water.
Immediatelycalla qualifiedservice technicianto inspect
the boiler and to replace any part of the control system
and any gas control that has been under water.
Boiler water —
6. DONOTuse petroleum-based cleaning orsealing com-
poundsinboiler system.Watersealdeterioration will oc-
cur, causing leakage between boiler sections, circulator
flanges, diaphragm tanks or other system components.
This can result in substantial property damage.
7. DO NOT use“homemade cures” or “boiler patent
medicines”. Serious damage to boiler, personnel and/
or property may result.
8. Continualfreshmakeupwaterwillreduceboilerlife.Min-
eralbuildupinsectionsreducesheattransfer, overheats
castiron,andcausessectionfailure.Additionofoxygen
and other gases can cause internal corrosion. Leaks
in boiler or piping must be repaired at once to prevent
makeup water.
9. Do not add cold water to hot boiler.Thermal shock can
cause sections to crack.
Glycol — potential fire hazard —
Allglycolisammablewhenexposedtohightemperatures.If
glycolis allowedtoaccumulateinoraroundthe boilerorany
other potential ignition source, a fire can develop.In order to
preventpotentialsevere personalinjury, deathor substantial
property damage from fire and/or structural damage:
• Never store glycol of any kind near the boiler or any
potential ignition source.
• Monitorandinspectthesystemandboilerregularlyfor
leakage. Repair any leaks immediately to prevent pos-
sible accumulation of glycol.
• Neveruse automotiveantifreezeor ethyleneglycolin
thesystem.Usingtheseglycolscanleadtohazardous
leakage of glycol in the boiler system.
1 Prepare boiler locationRead this first!
Installations must follow these codes:
• Local,state,provincial,andnationalcodes,laws,regulations
and ordinances.
• NationalFuelGasCode,ANSIZ223.1–latestedition.
• StandardforControlsandSafetyDevicesforAutomatically
FiredBoilers,ANSI/ASMECSD-1,whenrequired.
• NationalElectricalCode.
• ForCanadaonly:B149.1orB149.2InstallationCode,CSA
C22.1CanadianElectricalCodePart1andanylocalcodes.
Readand followthespecialinstructions fortheCom-
monwealthofMassachusetts,locatedonpage40
of this manual.
Certification
TheGWS-090Eboilergasmanifoldandcontrolsmet
safe lighting and other performance criteria when
boilerunderwenttestsspeciedinANSI Z21.13–
latest edition.
Before locating the boiler:
❏ Check for nearby connection to:
• Systemwaterpiping
• Ventingconnections
• Gassupplypiping
• Electricalpower
❏ Checkarea around boiler.Removeany combustiblematerials,
gasoline and other flammable liquids.
Failure to keep boiler area clear and free of com-
bustible materials, gasoline and other flammable
liquids and vapors can result in severe personal
injury, death or substantial property damage.
❏ Boilermust beinstalledsothatgas control system components
are protected from dripping or spraying water or rain during
operation or service.
❏ If new boiler will replace existing boiler, check for and correct
system problems, such as:
1. System leaks causing oxygen corrosion or section cracks from
hard water deposits.
2. Incorrectly-sized expansion tank.
3. Lackof antifreeze(when required)in boilerwatercausingsystem
and boiler to freeze and leak.
The boiler contains ceramic fiber and fiber-
glassmaterials.Usecarewhenhandlingthese
materials per instructions on page 21 of this
manual.Failuretocomplycouldresultinsevere
personal injury.
Failure to adhere to the guidelines below can
result in severe personal injury, death or sub-
stantial property damage.
3
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
1 Prepare boiler location continued
Service clearances
1. Provide minimum clearances for cleaning and servicing the
boiler and for access to controls and components as listed in
Table 1 below:
2. Provide at least screwdriver clearance to jacket front panel
screws for removal of front panel for inspection and minor
service. If unable to provide at least screwdriver clearance,
install unions and shutoff valves in system so boiler can be
moved for servicing.
Clearances
Flooring and foundation
Flooring
TheGWS-090Eboilerisapprovedforinstallationoncombustible
flooring, but must never be installed on carpeting.
Do not install boiler on carpeting even if foundation
is used. Fire can result, causing severe personal
injury, death or substantial property damage.
Foundation
1. Providea solidbrickor minimum2-inchthickconcretefounda-
tion pad if any of the following is true:
• oorcanbecomeooded.
• theboilermountingareaisnotlevel.
2. See Table 2, below, for minimum foundation dimensions.
Residential garage installations
Takethefollowingspecialprecautionswheninstallingthe boilerin
aresidential garage.If theboiler is located ina residential garage,
perANSIZ223.1,paragraph5.1.9:
• Mounttheboileraminimumof18inchesabovetheoorof
the garage to assure the burner and ignition devices will be
no less than 18 inches above the floor.
• Locateorprotect the boiler so it cannot bedamaged bya
moving vehicle.
Minimum clearance to combustible materials
1. Hot water pipes must be at least ½” from combustible mate-
rial.
2. Vent pipe must be at least 2 inches from combustible material
exceptwhereotherwisenotedinGWSVentingManual.
Small space installations
1. When the boiler is located in a closet or small space, provide
clearances no less than those shown in Figure 1.The clear-
ances are required to any surface, whether combustible or
non-combustible.
Table 2 Minimum foundation size
Boiler
model
number
Minimum
foundation
length
Minimum
foundation
width
GWS-090E 25” 18”
Figure 1 Minimum clearances in small spaces
Table 1 Minimum service clearances
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
4Part Number 550-110-737/1108
1 Prepare boiler location continued
Failure to followall instructionscanresultin flue gas
spillage and carbon monoxide emissions, causing
severe personal injury or death.
DonotinstalltheGWS-090Eintoacommonvent
with any other appliance. This will cause flue gas
spillage or appliance malfunction, resulting in pos-
sible severe personal injury, death or substantial
property damage.
GWS-090Eboilerscanonlybedirect-ventvented.
They cannot be chimney-draft vented or direct-ex-
haustvented.SeeGWSVentingManualfordetailed
installation instructions.
If you are removing an existing boiler from a shared
ventingsystem,theGWS-090Eboilercannotshare
theventsystem(itrequiresitsownvent).Youmust
test each appliance remaining on the old common
vent system individually to verify the vent system
still operates adequately. Follow guidelines below.
When removing boiler from existing common vent
system:
Atthetimeofremovalofanexistingboiler,thefollowingsteps
shall be followed with each appliance remaining connected to
the common venting system placed in operation, while the other
appliances remaining connected to the common venting system
are not in operation.
a. Seal any unused openings in the common venting system.
b. Visually inspect the venting system for proper size and hori-
zontal pitch and determine there is no blockage or restriction,
leakage,corrosionor other deficiencieswhichcouldcausean
unsafe condition.
c. Test vent system — Insofar as is practical, close all building
doors and windows and all doors between the space in which
the appliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any appliance not connected to the
common venting system.Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they will operate at
maximumspeed.Donotoperatea summerexhaustfan.Close
fireplace dampers.
d. Place in operation the appliance being inspected. Follow the
lighting/operatinginstructions.Adjustthermostatsoappliance
will operate continuously.
e. Test for spillage at draft hood relief opening after 5 minutes of
mainburneroperation.Usetheameofamatchorcandle.
f. Afterithasbeendeterminedthateachapplianceremaining
connectedtothecommonventingsystemproperlyventswhen
testedasoutlinedabove,returndoors,windows,exhaustfans,
fireplace dampers, and any other gas-burning appliance to
their previous conditions of use.
Any improper operation of common venting system should be
corrected so the installation conforms with the National Fuel
GasCode,ANSIZ223.1–latestedition.Correctbyresizingto
approach the minimum size as determined using the appropriate
tables in Part 11 of that code.Canadian installations must comply
with B149.1 or B149.2 Installation Code.
GWS-090E special vent system required
Vent system
TheGWS-090Eboilerrequiresaspecialventsystem,designed
forpressurizedventing.ModelGWS-090EisratedANSIZ21.13
Category IV (pressurized vent, likely to condense in the vent).
You may use any of the direct vent systems (combustion air
ducted to boiler) covered in GWSVenting Manual included in
the boiler envelope assembly.The GWS vent starter is a special
item,designedonlyforGWSandGWS-90E,availablefromeach
vendor.DonotattempttoconnecttheventtoaGWS-090Eboiler
with any other means.
DO NOT mix components from different systems.
The vent system could fail, causing leakage of flue
products into the living space.
Vent termination and combustion air supply
TheGWS-090Eboilermaybeventedthroughtherooforthrough
asidewall.FollowtheappropriateinstructionsintheGWSVenting
Manualfortheventsystemchosen.Themaximumventlength
depends on boiler size. Refer to the GWSVenting Manual to
determine acceptable vent length.
CombustionairfortheGWS-090Eboilermustbeducteddirectly
to the boiler from outside. For outside air (direct vent installa-
tion), two options are available for the flue/air termination. The
air supply must ALWAYS terminate at the same location as the
flue, using either:
1. Vertical direct vent installation — Obtain theThrough-Roof or
Through-UnusedChimneyTerminationKit.RefertotheGWS
VentingManual,packedwiththekitandtotheventmanufac-
turer’sinstructionsfortheventmaterialchosen.
2. Sidewall direct vent installation — Use theVent/Air Intake
Termination Kit shipped with the boiler. Refer to the GWS
VentingManualshippedwiththeboiler.
Vent system
5
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
Table 3 Corrosive contaminants and likely locations
TheGWS-90Eboiler must be direct vented (using
ducted outside air).
The vent/air termination must be installed in a
location that is free of the contaminants listed in
Table 3.
Allowingtheboilertooperatewithcontaminatedair
can cause damage to the boiler and vent system,
resulting in possible severe personal injury, death
or substantial property damage.
Please review the following information on potential combustion
air contamination problems.
See Table 3 for products and areas which may cause contami-
nated combustion air.
Air contamination
1 Prepare boiler location continued
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
6Part Number 550-110-737/1108
Air openings
Using outside air — direct venting
Combustion air can be ducted directly from outside to the GWS-
090Eboilerairintaketting.Thismethodisdenedasdirect vent
(also referred to as sealed combustion).Refer to the appropriate
instructionsintheGWSVentingManualandtheinstructionsin
this manual.Two options are available: sidewall or vertical direct
vent.Eachrequiresaspecialventcomponentkit.
Sizing air openings
Airopeningsprovideforventilationtopreventoverheatingofthe
boilercontrolsandboilerspace.Airisalsoneededforotherap-
pliances located in the same space.
UseFigure2,page7,selectingtheappropriateinstallationcondi-
tions.Note that the sizing given in Figure 2 applies only to GWS-
090EinstallationswithclearancesnosmallerthanshowninTable
1, page 3 of this manual. For smaller clearances, regardless of
how the air openings are arranged, two openings providing free
area of 1 square inch per 1,000 Btuh input of all appliances in
the space are required.
Airopeningsmustbesizedtohandleallappliances
and air movers (exhaust fans, etc.) using the air
supply.
The sizing given in Figure 2 is based on the National Fuel Gas
Code,ANSI Z223.1,allowingadequateairopeningforgravity-
vented gas appliances.The air openings recommended in Figure
2 will allow adequate ventilation and combustion air provided the
boiler room is not subjected to negative pressure due to exhaust
fansorothermechanicalventilationdevices.Referto the National
Fuel Gas Code for dealing with other conditions.
Louver allowance
The free area of openings means the area after reduction for any
installedlouversor grilles.Be sure to consider this reductionwhen
sizing the air openings.
Special considerations
Tight construction
ANSIZ223.1denesunusuallytightconstructionwhere:
a. Walls and ceilings exposed to the outside atmosphere have
a continuous water vapor retarder with a rating of 1 perm or
less with openings gasketed, and .. .
b. Weather-stripping has beenaddedonopenablewindowsand
doors, and . . .
c. Caulking or sealants are applied to areas such as joints
around windows and door frames, between sole plates and
floors, between wall-ceiling joints, between wall panels, at
penetrations for plumbing, electrical, and gas lines, and in
other openings.
For buildings with such construction, provide air openings into
the building from outside, sized per the appropriate case in
Figure 2.
Exhaust fans and air movers
The appliance space must never be under a negative pressure,
unlesstheappliancesareinstalledasdirectvent.Alwaysprovide
air openings sized not only to the dimensions required for the
firing rate of all appliances, but also to handle the air movement
rate of the exhaust fans or air movers using air from the building
or space.
Motorized air dampers
If the air openings are fitted with motorized dampers, electrically
interlock the damper to:
• Preventtheboilerfromringifthedamperisnotfullyopen.
• Shuttheboilerdownshouldthedampercloseduringboiler
operation.
To accomplish this interlock, wire an isolated contact (proving the
damper open) in series with the thermostat input to the boiler.
The boiler will not start if this contact is open, and will shut down
should it open during operation.
1 Prepare boiler location continued
7
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
Figure 2 Provide minimum air openings for GWS-090E boiler installations based on following:
1 Prepare boiler location continued
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
8Part Number 550-110-737/1108
Perform hydrostatic pressure test
Pressure test boiler before attaching water or gas piping or elec-
trical supply (except as noted below).
Prepare boiler for test
1. Removetheshippingnipple(fromGWS-090Esupplytapping)
and remove the boiler relief valve.Temporarily plug the relief
valve tapping with a ¾” NPT pipe plug.
2. Remove 1¼” nipple, reducing tee and drain valve from ac-
cessory bag. Install in boiler return connection as shown on
in Figure 18, item 3, page 36. Install circulator on either the
return or supply.
3. Remove 1¼”nipple, 1¼”tee, bushing and pressure/tempera-
turegauge from accessorybag.Pipe toboiler supply connec-
tionasshowninFigure18,item2,page36.(Usepipedope
sparingly.)
4. Connect a hose to boiler drain valve,the other end connected
toafreshwatersupply.Makesurehosecanalsobeusedto
drain boiler after test.
5. Connect a nipple and shutoff valve to system supply connec-
tion on the 1¼”tee.This valve will be used to bleed air during
the fill. (Valve and nipple are not included with boiler.)
6. Connect a nipple and shutoff valve to system return connec-
tion (at circulator flange if circulator installed on return).This
valve will be used to bleed air during the fill.(Valve and nipple
are not included with boiler.)
Fill and pressure test
1. Open the shutoff valves you installed on supply and return
connections.
Pressure test 2. Slowly open boiler drain valve and fresh water supply to fill
boiler with water.
3. When water flows from shutoff valves, close boiler drain
valve.
4. Close shutoff valves.
5. Slowlyreopenboilerdrainvalve untiltestpressureofnotmore
than 45 psi is reached on the pressure/temperature gauge.
6. Test at no more than 45 psi for no more than 10 minutes.
Donotleaveboilerunattended.Acoldwaterllcould
expand and cause excessive pressure, resulting in
severepersonalinjury,deathorsubstantialproperty
damage.
7. Make sure constant gauge pressure has been maintained
throughout test. Check for leaks.Repair if found.
Leaks must be repaired at once. Failure to do so
candamage boiler,resulting in substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Drain and remove fittings
1. Disconnect fill water hose from water source.
2. Drain boiler at drain valve or out hose, whichever provides
best access to drain. Remove hose after draining if used to
drain boiler.
3. Remove nipples and valves unless they will remain for use in
the system piping.
4. Removeplug from relief valvetapping.SeeSection3, page 9,
to replace relief valve.
2 Prepare boiler
Table 4 Manifold orifice sizing
Location Natural gas Propane gas
U. S.
Sea level –
2,000 ft over
2,000 ft Sea level –
2,000 ft over
2,000 ft
2.55 mm (Note 1) 1.60 mm (Note 1)
Canada
Sea level –
2,000 ft 2,000 –
4,500 Sea level –
2,000 ft 2,000 –
4,500
2.55 mm # 41 1.60 mm 1.45 mm
Note1: ForU.S.elevationsabove2,000feet,contactyourlocalsupplierfor
details.
Place boiler/crate near position
1. Leave boiler in crate and on pallet until installation site is
ready.
2. Moveentirecrateandpalletnexttoselectedlocation.
3. Remove crate.Leave boiler on pallet.
4. Remove boiler from pallet as follows:
a. Tilt left side of boiler up and place a board under left legs.
b. Tilt boiler the other way and place a board under right legs.
c. Slide boiler backwards off pallet and into position.
Do not drop boiler or bump jacket on floor or pallet.
Damage to boiler can result.
5. Check level.
a. Shim legs, if necessary.
b. Do not alter legs.
Inspect orifices and burners; connect air adapt-
er
1. Remove front jacket door. Remove air adapter fitting from air
inlethose(seeFigure17, page 35, items 9 and10)and screw
into opening on jacket top. Reconnect air hose to bottom of
air adapter fitting.Remove inlet air box top panel.(See Figure
16, item 13, page 34).
2. Checkforcorrectly-sizedmanifoldorifices.SeeTable4forsiz-
ing. (The orifice size is stamped on the orifice spud barrel.)
Placement and setup
Correctly-sized manifold orifices must be used.
Failure to do so will result in severe personal injury,
death or substantial property damage.
3. Reinstall inlet air box top panel and jacket door.
Do not operate boiler without inlet air box top panel
secured in place. Failure to comply could result in
severepersonalinjury,deathorsubstantialproperty
damage.
9
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
Table 5 Water pipe size (based on 20 °F rise)
Boiler
model
number
To
system From
system
GWS-090E 1” 1”
Circulator
The circulator is shipped loose (wiring pre-attached to boiler) to
allow you to locate it either in the return or supply piping, as de-
sired.See Figures 3 and 4, page 10, for a typical installation.Pipe
the expansion tank to the suction side of the circulator whenever
possible. Install an air separator in the supply piping. Connect
the expansion tank to the air separator only if the separator is
onthesuctionsideofthecirculator.Alwaysinstallthesystemll
connection at the same point as the expansion tank connection
to the system.
Expansion tank
Diaphragm- or bladder-type expansion tank — Figure 3,
page 10
1. Ensure expansion tank size will handle boiler and system
watervolumeand temperature.Tankmust be located in boiler
return piping as close to boiler as possible, before inlet side
ofcirculator.Seetankmanufacturer’sinstructionsfordetails.
2. Install an automatic air vent as shown.
Closed-type expansion tank — Figure 4, page 10
1. Ensureexpansiontanksizewillhandleboilerandsystemwater
volumeandtemperature.Seetankmanufacturer’sinstructions
for details.
2. Connect tank to ½”NPTtappinglocatedbehindsupply outlet,
using ½” NPT piping. Pitch any horizontal piping up towards
tank 1 inch per 5 feet of piping.
Undersizedexpansiontankscause system water
to be lost from relief valve and makeup water to be
addedthroughllvalve.Eventualsectionfailurecan
result.
Water piping — multiple zone systems
Install system piping using either circulator zoning or zone valve
zoning. Install expansion tank on suction side of system pump.
Alwaysconnectlllineonlyat the expansiontank—neverat
another point in the system.
3 Install water piping
General
IfinstallationistocomplywithASMEorCanadianrequirements,
an additional high temperature limit is needed. Install control in
supply piping between boiler and isolation valve. Set second
controltominimum20°Fabovesetpointofrstcontrol.Maximum
allowable setpoint is 240 °F. See page 18 for wiring.
Alowwatercutoffdeviceisrequiredwhenboilerisinstalledabove
radiation level or by certain state or local codes or insurance
companies.Uselowwatercutoffdesignedforwaterinstallations.
Electrodeprobe-typeis recommended.Purchase andinstallin
tee in supply piping above boiler.
Usebackowcheckvalveincoldwatersupplyifrequiredbylo-
cal codes.
See Figure 3 (diaphragm-type or bladder-type expansion tank)
or Figure 4 (closed-type expansion tank) on page 10, and Table
5, for near-boiler and single-zone systems designed for return
water at least 130 °F.
See page 9 for multiple zone systems.
See page 10 for boilers used with refrigeration systems.
Near-boiler piping
Relief valve
Installrelief valvevertically in¾”tapping on side ofboiler.Seethe
tagattachedtothereliefvalveformanufacturer’sinstructions.
To avoid water damage or scalding due to valve
operation, discharge line must be connected to re-
lief valve outlet and run to a safe place of disposal.
Terminate the discharge line to eliminate possibility
of severe burns should the valve discharge.
• Dischargelinemustbeasshortaspossibleandbe
the same size as the valve discharge connection
throughout its entire length.
• Dischargelinemustpitchdownwardfromthevalve
andterminateatleast6”abovethefloordrainwhere
any discharge will be clearly visible.
• Thedischargelineshallterminateplain,notthread-
ed, with a material serviceable for temperatures of
375 °F or greater.
• Donotpipethedischargetoanyplacewherefreez-
ing could occur.
• Noshutoffvalveshallbeinstalledbetweentherelief
valveand boiler, or in thedischargeline.Donotplug
or place any obstruction in the discharge line.
• Failuretocomplywiththeaboveguidelinescould
result in failure of the relief valve to operate, result-
ing in possibility of severe personal injury, death or
substantial property damage.
• Testtheoperationofthevalveafterllingandpres-
surizingsystembyliftingthelever.Makesurethe
valve discharges freely. If the valve fails to operate
correctly, replace it with a new relief valve.
Near-boiler piping continued
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
10 Part Number 550-110-737/1108
Figure 3 Diaphragm- or bladder-type expansion tank:
Piping to single-zone system using
diaphragm-type or bladder-type expansion
tank. See Table 5, page 9, for piping sizes.
Figure 4 Closed-type expansion tank: Piping to single-
zone system using closed-type expansion
tank. See Table 5, page 9, for piping sizes.
Figure 5 Piping refrigeration systems
3 Install water piping continued
Water piping — refrigeration systems
Prevent chilled water from entering boiler
Install boiler so that chilled medium is piped in parallel with the
heatingboiler.Useappropriatevalvestopreventchilledmedium
fromentering boiler. SeeFigure 5 fortypical installation ofbalanc-
ing valve and check valve.
Install boiler so that chilled medium is piped in par-
allelwithheatingboiler.Useappropriatevalvesto
preventchilledmedium from enteringboiler.Consult
I=B=R Installation and Piping Guides.
If boiler is connected to heating coils located in
air handling units where they can be exposed to
refrigerated air, use flow control valves or other au-
tomatic means to prevent gravity circulation during
cooling cycle.Circulation of cold water through the
boilercouldresultin damagetothe heatexchanger,
causing possible severe personal injury, death or
substantial property damage.
If system includes radiant heating circuits, provide
pipingandcontrolsto regulate the temperature sup-
plying the radiant circuits. Failure to comply could
result in substantial property damage.
UseFigure3orFigure4onlyforsystemsdesigned
for return water at least 130 °F. For systems with
lowreturn watertemperaturepossible,suchascon-
verted gravitysystemsand radiantheatingsystems,
install bypass piping (see page 11) to protect boiler
against condensation.Failure to prevent low return
water temperature to the boiler could cause corro-
sion of the boiler sections or burners, resulting in
severepersonalinjury,deathorsubstantialproperty
damage.
11
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
Figure 6 System bypass piping in boiler loop with
separate system circulator, using primary/
secondary piping
Figure 7 Boiler bypass piping — use only for high
water content systems — DO NOT use for
radiant panel systems
Near-boiler piping continued
Install all components specified above and adjust valves as described to prevent low temperature in the boiler.Failure to
prevent low water temperature in the boiler could cause corrosion of the boiler sections or burners, resulting in severe
personal injury, death or substantial property damage.
3 Install water piping continued
System bypass method
1. ApplybypasspipingofFigure6tohighwatercontentsystems,
radiant panel systems or any system that is likely to operate
with low return water temperature for extended periods.
2. Thebypassarrangementshownprotectstheboilerfromdam-
age caused by condensate corrosion due to low return water
temperature and protects low temperature systems from too
high a supply temperature.
3. Adjustthebypassvalvesasindicatedbelow.
Adjust Bypass valves 1 and 2 as follows:
1. Start with valve 2 fully closed, valve 1 fully open.
2. Slowlyopenvalve2whileclosingvalve1.Adjustthevalves
until the boiler pressure/temperature gauge reads 160 °F or
higher.Asyouopenthevalves,pauselongenoughtoallow
temperatures to level off. It takes a while for the boiler water
temperature to rise as the flow changes.
3. Bypass valve 2 allows hot boiler outlet water to blend with
colder return water, raising thesupply temperature tothe boiler.
Bypass valve 1 balances the pressure drop through valve 2.
4. The purpose of this piping is to raise the return water tem-
perature to the boiler enough to prevent condensation of flue
gases.
Boiler bypass method
1. ApplybypasspipingofFigure7tohighwatercontentsystems,
such as converted gravity systems.
2. Thebypassarrangementshownprotectstheboilerfromdam-
age caused by condensate corrosion due to low return water
temperature. This method does not provide protection from
high temperature water being supplied to the system.
3. DO NOT apply this piping to radiant panel systems.
4. Adjustthebypassvalvesasindicatedbelow.
Adjust Bypass valves 1 and 2 as follows:
1. Start with valve 1 fully closed, valve 2 fully open.
2. Slowlyopenvalve1whileclosingvalve2.Adjustthevalves
until the boiler pressure/temperature gauge reads approxi-
mately60°Fhigherthanthesystemtemperaturegauge.As
youopenthevalves,pauselongenoughtoallowtemperatures
to level off. It takes a while for the boiler water temperature to
rise as the flow changes.
3. Bypass valve 1 controls system flow rate. Bypass valve 2
controls flow through the boiler.
4. The purpose of this piping is to cause a high enough tem-
perature rise in the boiler that the average temperature will
be warm enough to prevent condensation of flue gases.
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
12 Part Number 550-110-737/1108
Figure 8 Gas supply piping
Table 6 Pipe capacity for 0.60 specific gravity natural gas
1. Remove jacket front panel and see Figure 8 to pipe gas to
boiler.
a. Install drip leg at inlet of gas connection to boiler. Where local
utilityrequiresdrip leg to be extendedtothefloor, useappropriate
length of nipple between cap and tee.
b. Install ground joint union for servicing, when required.
c. Install manual shutoff valve in gas supply piping outside boiler
jacket when required by local codes or utility requirements.
d. In Canada — When using manual main shutoff valve, it must be
identified by the installer.
2. Support piping with hangers, not by boiler or its accesso-
ries.
3. Purge all air from gas supply piping.
4. Before placing boiler in operation, check boiler and its gas
connection for leaks.
a. Close manual main shutoff valve during any pressure testing at
less than 13” w.c.
b. Disconnect boiler and gas valve from gas supply piping during
any pressure testing greater than 13” w.c.
Donotcheckforgasleakswithanopename—Use
bubble test. Failure to use bubble test or check for
gas leaks can cause severe personal injury, death
or substantial property damage.
5. Usepipedopecompatiblewithpropanegases.Applysparingly
only to male threads of pipe joints so that pipe dope does not
block gas flow.
Failure to apply pipe dope as described in this
manual can result in severe personal injury, death
or substantial property damage.
Natural Gas:
1. SeeTable6forpipe length and diameter.Base on ratedboiler
input (divide by 1,000 to obtain cubic feet per hour).Table 6
is only for gas with specific gravity 0.60, with a pressure drop
through the gas piping of 0.30” w.c. For additional gas pipe
sizinginformation,seeANSIZ223.1(B149.1orB149.2for
Canadian installations).
2. Inlet pressure required at gas valve inlet:
• Maximum:13”w.c.
• Minimum:5”w.c.
• Manifoldgaspressure:3.5”w.c.athighre(0.90”w.c.atlowre
while in low fire at start-up)
3. Install 100% lockup gas pressure regulator in supply line if
inletpressureexceeds13”w.c.Adjustfor13”w.c.maximum.
Propane Gas:
1. Contact gas supplier to size pipes, tanks and 100% lockup
gas pressure regulator.
2. Adjustpropanesupplyregulatorprovidedbygassupplierfor
13” w.c. maximum pressure.
3. Inlet pressure required at gas valve inlet:
• Maximum:13”w.c.
• Minimum:11”w.c.
• Manifoldgaspressure:10”w.c.athighre(3.5”w.c.atlowre
while in low fire at start-up)
4 Venting and combustion air
Install vent piping and air piping (if used) per appropriate instruc-
tions in the GWSVenting Manual, included in boiler envelope
assembly.
RefertoGWSVentingManualandtoBoilerManualSection1,
page 4, regarding requirements for:
• ventsystem
• combustionairopenings
• combustionairquality
TheGWS-090Eboilermustbedirectventedonly
(combustion air ducted to boiler) and supplied with
combustionand ventilationair as described in GWS
Venting Manual, packed in envelope assembly
with boiler, and Section 1 of this manual, page 4.
Failure to do so will cause severe personal injury or
death.
Readandfollowthespecialinstructions forthe Com-
monwealthofMassachusetts,locatedonpage 40
of this manual.
5 Gas piping
13
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
For your safety, turn off electrical power supply
at service entrance panel before making any
electrical connections to avoid possible electric
shock hazard. Failure to do so can cause severe
personal injury or death.
Figure 9 Field wiring connections — service switch and thermostat (or end switch) provided by installer
6 Field wiring
Thermostat
1. Connect thermostat as shown on wiring diagram on boiler.
2. Install on inside wall away from influences of drafts, hot or
cold water pipes, lighting fixtures, television, sunrays or fire-
places.
3. Ifthermostathasa heatanticipator, setheatanticipatorinther-
mostatto match powerrequirementsofequipmentconnected
to it. If connected directly to boiler, set per wiring diagram,
Figure13,onpage18.Forotherdevices,seemanufacturer’s
specications.Alsoseeinstructionswiththermostat.
Junction box (furnished)
1. Connect120VACpowerwiring.SeeFigure9.
2. Fused disconnect or service switch (15 amp.recommended)
may be mounted on this box.For those installations with local
codeswhichprohibitinstallationoffuseddisconnectorservice
switchonboiler,installa2x 4 coverplateontheboilerjunction
box and mount the service switch remotely as required by the
code.
Wiring multiple zones
Seezonevalvemanufacturer’sliteratureforwiringandapplication.
Aseparatetransformerisrequiredtopowerzonevalves.Zoning
with circulators requires a relay for each circulator.
TheGWS-090Econtrolmoduleispolarity-sensitive.Thehotandneutralwiresmustbeconnectedtothecorrectleads.
AashingPOWER lightusuallyindicatesreversedpolarityof120VACleadwires.
Wiring must be N.E.C. Class 1.
If original wiring as supplied with boiler must be
replaced, use only type 105 °C wire or equivalent.
Boiler must be electrically grounded as required
by National Electrical Code ANSI/NFPA 70-latest
edition.
Electrical installation must comply with:
1. NationalElectricalCodeandanyothernational,state,provin-
cial or local codes or regulations.
2. InCanada,CSAC22.1CanadianElectricalCodePart1,and
any local codes.
Wiring connections
Boilerisshippedwithcontrolscompletelywired,exceptspillswitch
and vent damper. See wiring diagram on page 18. Circulator is
shipped loose, but wiring harness is pre-attached to the boiler.
Connect wires in circulator junction box.
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
14 Part Number 550-110-737/1108
7 Start-up
Check for gas leaks
Before starting the boiler, and during initial opera-
tion, smell near the floor and around the boiler for
gas odorant or any unusual odor. Do not proceed
with start-up if there is any indication of a gas leak.
Repair any leak at once.
Propaneboilersonly—Yourpropanesuppliermixes
an odorant with the propane to make its presence
detectable.Insomeinstances,theodorantcan fade
and the gas may no longer have an odor.
• Propane gas can accumulate at floor level.Smell near
the floor for the gas odorant or any unusual odor.If you
suspect a leak, do not attempt to light the pilot.
• Usecautionwhenattemptingtolightthepropanepilot.
This should be done by a qualified service technician,
particularly if pilot outages are common.
• Periodicallychecktheodorantlevelofyourgas.
• Inspectboilerandsystematleastyearlytomakesure
all gas piping is leak-tight.
• Consultyourpropanesupplierregardinginstallationof
a gas leak detector.There are some products on the
marketintendedforthispurpose.Yoursuppliermaybe
able to suggest an appropriate device.
Determine if water treatment is needed
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Eliminateallsystemleaks.Continualfreshmakeup
waterwillreduceboilerlife.Mineralscanbuildup
insections,reducing heattransfer,overheatingcast
iron, and causing section failure.
Verify water chemistry
Consultlocalwatertreatmentcompanies forunusually hard water
areas(above7grainshardness)orlowpHwaterconditions(below
7.0). Boiler water pH of 7.0 to 8.5 is recommended.
Freeze protection (when used)
Useantifreezemadeespeciallyforhydronicsystems. Inhibited
propylene glycol is recommended.
Do not use ethylene glycol, automotive or undiluted
antifreeze. Severe personal injury or death can
result.
1. Determine antifreeze quantity according to system water
content.Boiler water content is listed on page 39.Remember
to include expansion tank water content.
2. Followantifreezemanufacturer’sinstructions.
3. A50%solutionofpropyleneglycol/waterprovidesmaximum
protection to about -30 °F.
4. Localcodesmayrequirebackflowpreventeror actualdiscon-
nect from city water supply.
5. When using antifreeze in a system with automatic fill, install a
water meter to monitor water makeup. Glycol will leak before
thewaterbeginstoleak,causingglycolleveltodrop.Added
water will dilute the antifreeze, reducing the freeze protection
level.
Fill the system with water
1. Close manual and automatic air vents and boiler drain cock.
2. Fill to correct system pressure. Correct pressure will vary
with each application. Typical cold water fill pressure for a
residential system is 12 psi.
3. Purge air from system:
a. Connect a hose to purge valve or valves, if installed.Route hose
to an area where water can drain and be seen.
b. Closetheboilerorsystemisolationvalvebetweenthepurgevalve
and fill connection to the system.
c. Close zone isolation valves.
d. Open quick-fill valve on cold water makeup line.
e. Open purge valve.
f. Onezoneatatime,opentheisolationvalves.Allowwatertorun
through the zone, pushing out the air.Run until no noticeable air
flow is present.Close the zone isolation valves and proceed with
the next zone.Follow this procedure until all zones are purged.
g. Close the quick-fill water valve and purge valve and remove the
hose.Open all isolation valves.Watch that system pressure rises
to correct cold-fill pressure.
h. Afterthesystemhasoperatedforawhile,eliminateanyresidual
air by using the manual air vents located throughout the sys-
tem.
i. If purge valves are not installed in system, open manual air vents
in system one at a time, beginning with lowest floor. Close vent
when water squirts out. Repeat with remaining vents.
4. Open automatic air vent (diaphragm-type or bladder-type
expansion tank systems only) one turn.
5. Open other vents:
a. Starting on the lowest floor, open air vents one at a time until
water squirts out.
b. Repeat with remaining vents.
6. Refill to correct pressure.
Inspect system water piping
Afterllingtheboilerandsystemwithwater,inspectallpiping
throughout the system for leaks. If found, repair immediately.
Repeat this inspection after the boiler has been started and the
system has heated up.
Leaksmustberepairedatonce.Failuretodoso can
damage the boiler, resulting in substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
Inspect base insulation
Check to make sure insulation is secure against all four sides of
the base. If insulation is damaged or displaced, do not operate
boiler.Replace or reposition insulation.
Failure to replace damaged insulation or reposition
insulationcan resultina firehazard,causingsevere
personal injury, death or substantial property dam-
age.
The boiler contains ceramic fiber and fiberglass
materials.Usecarewhenhandlingthesematerials
per instructions on page 21 of this manual. Failure
to comply could result in severe personal injury.
15
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
7 Start-up continued
Check burner flame — Pilot burner
Proper pilot flame (see Figure 10):
1. Blue flame.
2. Inner cone engulfing pilot flame sensor.
3. Pilot flame sensor glowing cherry red.
Improper pilot flame:
1. Overfired — Large flame lifting or blowing past pilot flame
sensor.
2. Underred—Smallame.Innerconenotengulngpilotame
sensor.
3. Lackofprimaryair—Yellowametip.
4. Incorrectly heated pilot flame sensor.
Check burner flames — Main burner
Proper main burner flame (see Figure 11):
1. Yellow-orange streaks may appear (caused by dust). (The
GWS-090Ewilloperateatlowrefortherst60seconds.)
Improper main burner flame:
1. Overfired — Large flames.
2. Underred—Smallames.
3. Lackofprimaryair—Yellowtippingonames(sootingwill
occur).
Figure 11 Typical main burner flame
Verify operation
Figure 10 Typical pilot burner flame
Operate boiler
DONOTproceedwith boileroperationunlessboiler
and system have been filled with water and all in-
structions and procedures of previous manual sec-
tions have been completed. Failure to do so could
resultinseverepersonalinjury, death or substantial
property damage.Before starting the boiler . . .
• Read manual Sections 8 and 9 and “Operating
instructions”, page 19.
• Verifytheboilerandsystemarefullofwater.
• VerifytheStart-uppreparationprocedures ofthis
section have been completed.
Start the boiler
Follow“Operatinginstructions”,page19.Ifboilerfailstostart,see
“Ifboilerdoesn’tstart...Checkfor:”onthispage.
Check system and boiler
Eliminateallsystemleaks.Continualfreshmakeup
waterwillreduceboilerlife.Mineralscanbuildup
insections,reducing heat transfer, overheatingcast
iron, and causing section failure.
If you discover evidence of any gas leak, shut down
the boiler at once.Find the leak source with bubble
testandrepairimmediately.Do notstartboileragain
until corrected.Failure to comply could result in se-
vere personal injury, death or substantial property
damage.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to
boiler will occur, resulting in substantial property
damage.
1. Check system piping for leaks. If found, shut down boiler
and repair immediately.
2. Vent air from systemusingmanualvents.Airinthesystem
will interfere with circulation and cause heat distribution prob-
lems and noise.
3. Inspectvent system thoroughlyforsignsof deteriorationfrom
corrosion, physical damage or sagging. Verify that masonry
chimney liners are in good condition, with no obstructions,
and there are no openings into the chimney.
Venting system must be sealed gas-tight to prevent
flue gas spillage and carbon monoxide emissions.
Failure to comply could result in severe personal
injury or death.
4. Check around the boiler for gas odor following the proce-
dure of Section 7, page 14 of this manual.
5. Verify operation using procedures below. Perform checkout
procedureinSection8,page16,andllinthe“Installation
and service certificate”.
If boiler doesn’t start . . . Check for:
1. Loose connections, blown fuse or service switch off?
2. High limit switch set below boiler water temperature?
3. Thermostat set below room temperature?
4. Gas not turned on at meter or boiler?
5. Incoming gas pressure less than:
5” w.c. for natural gas? 11” w.c. for propane gas?
6. Ifnoneoftheabovecorrectstheproblem,see“Troubleshoot-
ing,” page 25 of this manual.
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
16 Part Number 550-110-737/1108
Boiler model _______________________________________________________________ Series ____________
CP number _______________________________________ Date installed _________________________________
Measured Btuh input ____________
Installer _______________________ ______________________________ ____________________________
(company) (address) (phone)
__________________________________
(installer’s signature)
8 Checkout procedure
Boiler and heat distribution units filled with water?❏
Automaticairvent,ifused,openonefullturn?❏
Airpurgedfromsystem?❏
Airpurgedfromgaspiping?Pipingcheckedforleaks?❏
Correctly sized manifold orifices installed? Refer to manual❏Section 2 to check size and fuel type.
Correctly sized manifold orifices must be used.
Failure to do so will cause severe personal injury,
death or substantial property damage.
Followed operating instructions on boiler or in manual Sec-❏tion 9 for proper start-up?
Verify that the boiler switches to high fire after 60 seconds of❏main flame operation.
Proper burner flame observed at high fire? Refer to Check❏burner flame, manual Section 7.
Test limit control — While burners are operating, move indi-❏cator on limit control below actual boiler water temperature.
Burners should go off while circulator continues to operate.
Raise setting on limit control above boiler water temperature
and burners should reignite.
Test additional field-installed controls — If boiler has a low❏water cutoff, additional high limit or other controls, test for
operation as outlined by manufacturer. Burners should be
operating and should go off when controls are tested.When
controls are restored, burners should reignite.
Test ignition system safety device:❏
Connectmanometertooutletsideofgasvalve.Startboiler,a. allowing for normal start-up cycle to occur and main burn-
ers to ignite.With main burners on, manually shut off gas
supply at manual main shutoff gas valve.Burners should
gooff.Openmanualmainshutoffgasvalve.Manometer
should confirm there is no gas flow.Pilot will relight, flame
sensing element will sense pilot flame and main burners
reignite.
Setlimitcontrol(s)tosystemtemperaturerequirements.Adjust❏balancing valves and controls to provide design temperature
to system.
For multiple zones, adjust flow so it is about the same in❏each zone.
Verify thermostat heat anticipator (if available) set properly?❏Refer to Field wiring, manual Section 6, Thermostat(s).
Cycle boiler with thermostat — Raise to highest setting and❏verify boiler goes through normal start-up cycle. Lower to
lowest setting and verify boiler goes off.
Measurenaturalgasinput:❏
Operate boiler 10 minutes.a. Turn off other appliances.b.
Atnaturalgasmeter,measuretime(inseconds)requiredc. to use one cubic foot of gas.
Calculate gas input:d.
Btuh calculated should approximate input rating on boilere. rating label.
Check manifold gas pressure by connecting manometer to❏
downstreamtesttappingonmaingasvalve.Manifoldpres-
sure for natural gas should be 3.5” w.c. and for propane gas
should be 10” w.c.
Observe several operating cycles for proper operation.❏
Set room thermostat to desired room temperature.❏
Fill in Installation and service certificate below?❏
Review all instructions shipped with this boiler with owner or❏maintenanceperson.Returninstructionstoenvelopeandgive
to owner or place in pocket inside front panel in boiler.
Installation instructions have been followed.
Checkout sequence has been performed.
Above information is certified to be correct.
Information received and left with owner/maintenance person.
Installation and service certificate
17
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
9 Sequence of operation
Figure 12 GWS-090E control module sequence of operation (based on indicator light status)
Followallproceduresgiveninthismanualand“Op-
eratingInstructions”,Section10,page19andonthe
insideof the boiler jacket panel, when operatingthe
boiler.Failuretodosocouldresultinseverepersonal
injury, death or substantial property damage.
1. Raise room thermostat to call for heat.
2. Inducerandcirculatorenergize.Afterpressureswitchproves
proper airflow, control module initiates 10-second prepurge.
3. Control module sparks the pilot and opens pilot valve in main
gas valve.
a. If pilot does not light within 15 seconds, pilot valve is closed and
sparkgeneratoristurnedoff.Controlmoduleinitiatesa15-second
postpurge, then starts a new cycle.
b. If pilot does light and control module senses flame current, spark
generator is turned off and main valve opens.
4. The GWS-090E timer relay delays high fire for the first 60
seconds of main flame.
5. During main burner operation:
a. Control module monitors pilot flame current.If signal is lost, main
valve closes, spark generator activates and sequence returns to
step 4.
b. If power is interrupted, control system shuts off pilot and main
gas valves and restarts at step 1 when power is restored.
6. In the event the limit control shuts down the boiler — The
control module closes the gas valve, but keeps the inducer
operating for 15-second postpurge.
— The circulator continues to operate.
7. Lowerroomthermostatsettingtostopcallforheat.Thermostat
issatisfied — Pilot and main gas valvesare closed — Inducer
operates for 15-second postpurge — Circulator is shut off.
8. Boiler is now in the off cycle.
9. Repeat steps 1 through 6 several times to verify operation.
10. Return the thermostat to normal setting.
11. Set thermostat heat anticipator setting per wiring diagram,
page 18.
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
18 Part Number 550-110-737/1108
Figure 13 Wiring diagram — GWS-090E boilers
9 Sequence of operation continued
19
Part Number 550-110-737/1108
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
10 Operating instructions
GWS-090E
Gas-Fired Water Boiler – Boiler Manual
20 Part Number 550-110-737/1108
Followthe“Serviceandmaintenance”proceduresgiventhroughoutthismanualandincomponentliteratureshipped
withtheboiler.See“Readthisrst”onpage2.Failuretoperformtheserviceandmaintenancecouldresultindamage
to the boiler or system. Failure to follow the directions in this manual and component literature could result in severe
personal injury, death or substantial property damage.
Table 6 Service and maintenance schedules (service technician and user)
11 Service and maintenance
Service technician
(see following pages for instructions)
Owner maintenance
(see User’s Information Manual for instructions)
An n n u A l s t A r t -u p
❏Inspect:
Reported problems
Boiler area
Air openings
Flue gas vent system
Pilot and main burner flames
Water piping
Boiler heating surfaces
Burners, base and inlet air box
Condensate drain system
❏Service:
Inducer motor
Oiled-bearing circulators
❏Start-up:
Perform start-up per manual
❏Check/test:
Gas piping
Cold fill and operating pressures
Air vents and air elimination
Limit controls and cutoffs
Expansion tank
Boiler relief valve
❏Review:
Review with owner
❏Cleaning boiler heating surfaces
❏Daily Check boiler area
Check boiler pressure/
temperature gauge
Check air openings
❏Monthly Check boiler piping
Check venting system
Check condensate drain system
Check boiler relief valve
Check automatic air vents (if used)
Check pilot and main burner flames
Check and clean vent termination &
air intake screens
❏Periodically Test low water cutoff (if used)
Oil inducer motor
❏Every 6 months Operate relief valve
❏End of season Shut down procedure
Table of contents
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