Weil-McLain PER 550-141-396/0801 User manual

Part number 550-141-396/0801
Electric-Hydronic Boilers
Installation Instructions
These Instructions must be used only by a qualified installer/service
technician.Readtheseinstructionscompletelybeforebeginning.Failureto
follow these instructions can cause severe personal injury, death or
substantial property damage.
When calling or writing about the boiler— Please have the boiler model
number from the boiler rating label and the CP number from the boiler
jacket.YoumaylisttheCPnumberinthespaceprovidedontheInstallation
and service certificate found on page 9.
PER Series 3
Installer Read all instructions before
installing. Follow all instructions in
proper order to prevent personal
injury or death.
• Considerpipingandinstallationwhendetermining
boiler location.
• Any claims for damage or shortage in shipment
must be filed immediately against the
transportation company by the consignee.
User
• This manual is for use only by
yourqualifiedheatinginstaller/
service technician.
• Werecommendregularservice
by a qualified service
technician,at least annually.

Part number 550-141-396/0801
2
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Please read before proceeding
Failure to adhere to the guidelines on this page can result in severe personal injury,death
or substantial property damage.
When servicing boiler —
• To avoid electric shock,disconnect electrical supply before performing maintenance.
• To avoid severe burns,allow boiler to cool before performing maintenance.
• Theboilercontainsfiberglassmaterials.Usecarewhenhandlingthesematerialsperinstructionsonpage
11 of this manual.
Boiler operation —
• Do not block flow of ventilation air to boiler.Will cause components to overheat.
• Shouldoverheatingoccur,donotdisconnectelectricalsupplytocirculator.Instead,shutofftheelectrical
supply at a location external to the appliance.
• Donotusethisboilerif anyparthasbeenunderwater.Immediatelycall aqualifiedservicetechnicianto
inspect the boiler and to replaceany part of the control system that has been under water.
Boiler water —
• Donotusepetroleum-basedcleaningorsealingcompoundsinboilersystem.Thiscanresultinsubstantial
property damage.
• Do not use"homemade cures"or "boiler patentmedicines".Serious damage to boiler,personneland/or
property may result.
• Continual fresh makeup water will reduce boiler life.Mineral buildup in section reduces heat transfer,
overheats cast iron, and causes section failure. Addition of oxygen and other gases can cause internal
corrosion.Leaks in boiler or piping must be repaired at once to prevent makeup water.
• Do not add cold water to hot boiler. Thermal shock can cause sections to crack.
Glycol — potential fire hazard —
All glycol is flammable when exposed to high temperatures.If glycol is allowed to accumulate in or around
the boiler or any other potential ignition source, a fire can develop. In order to prevent potential severe
personal injury, death or substantial property damage from fire and/or structural damage:
• Never store glycol of any kind near the boileror any potential ignition source.
• Monitorandinspectthesystemandboilerregularlyforleakage.Repairanyleaksimmediatelytoprevent
possible accumulation of glycol.
• Neveruseautomotiveantifreezeorethyleneglycolinthesystem.Usingtheseglycolscanleadtohazardous
leakage of glycol in the boiler system.
Hazard Definitions
The following defined terms are used throughout these Instructions to bring attention to the presence of hazards
of various risk levels,or to important information concerning the life of the product.
Indicatespresenceofhazardsthatwillcauseseverepersonalinjury,deathorsubstantialproperty
damage.
Indicatespresenceof hazardsthatcancauseseverepersonalinjury,deathorsubstantialproperty
damage.
Indicatespresenceofhazardsthatwillorcancauseminorpersonalinjuryorpropertydamage.
Indicatesspecialinstructionsoninstallation,operationormaintenancethatareimportantbut
not related to personal injury or property damage.

Part number 550-141-396/0801 3
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Mounting the boiler
Normally,theboilerwillbeinstalledagainst a frameor
masonry wall. If thewall surfaceisroughoruneven,it
may be necessary to mount plywood on the wall,then
mount the boiler on the plywood. Refer to
“Dimensions”onpage12and“Ratings”onpage13,and
note the boiler weight. Be sure that the wall structure
will support the boiler and its piping.
The 9/16" top mounting holes and 5/16" lower mounting
holes are on 16-inch centers to permit installation on
studs in standard wall construction. The use of ¼" x
2½"lagscrewsisrecommendedformountingtheboiler.
The head diameters of the top two screws must not
exceed 9/16".
1. Locate the top mounting holes so that the boiler
will be level. Install the screws so that the heads
protrude ¾" from the wall.
2. Raisetheboiler to mountingpositionbyplacing a
boardacrossthebottomoftheboilerorbygrasping
the lower left and right inside corners. Do not
attempt to lift the boiler by grasping the bottom
jacket cross tie.
3. Placethetopbracketsoverthelagscrewsand then
install screws through the lower mounting holes.
The top screws can now be tightened.
Locating the boiler
The compact construction of the electric-hydronic
boiler permits installation in an alcove, storeroom or
other small area. The location chosen should have
convenient electrical service.
Allow sufficient clearance above and below the boiler
cabinet to permit installation of supply and return
piping.Aminimum of 6inchesis required atthe topof
the boiler for installation and accessories. A clearance
of 10 inches is required on the right hand side for
removal of the elements.
General instructions
The Weil-McLain Model PER electric-hydronic boilers
areassembledunitsdesignedforuseinforcedhotwater
heatingsystems.Thesuggesteddesigntemperaturerise
throughtheboileris20°F.ThePERboilerisa complete
package including the circulator and expansion tank.
Low flow rates through the boiler at elevated
temperatures should be avoided. The structure to be
heatedshouldbeinsulatedintheconventionalmanner
usedinyourareaforelectricallyheatedbuildings. Boiler
mustbe installed inaccordancewith these instructions
so as not to void our warranty.
Open the boiler crate and check the contents. In the
event of shortage or damage, notify the transportation
company immediately.
Expansion tank sizing
Undersized expansion tanks cause system water to be
lostfromrelief valveand makeup water addedthrough
fill valve. Eventual section failure can result.
If a Fill-Trol system is used, refer to Table 1 for proper sizing. If Fill-Trol
actionisnotdesired,sizetheexpansiontankaccordingtothewatervolume
of the system.If a standard closed expansion tank (without a diaphragm)
isused,theairventtappingonthe boilercastingmakesaconvenientpoint
of connection.The No. 109 Fill-Trol is furnished as standard equipment.
Table 1 Expansion tank sizing (Tank sizing based on 200 °F
average system temperature.)
Hydrostatic pressure test
Pressure test boiler before attaching piping or electrical supply.
1. Install air vent in tapping on top of boiler.
2. Plug remaining tappings,including relief valve opening.
3. Connect water supply. Fill boiler and purge all air. For more than 10
minutes,pressure-test at 1½ times maximum working pressure.
Do not leave boiler unattended. Cold water fill could
expand and cause excess pressure, resulting in severe
personal injury, death or substantial property damage.
4. Checkformaintainedgaugepressure. Visuallycheckforleaksif gauge
pressure drops.
5. Drain boiler and repair leaks if found.
Leaks must be repaired at once. Failure to do so can
damageboiler,resultinginsubstantialpropertydamage.
6. Retest boiler after repairing leaks.
7. Remove testing plugs and air vent.
Do not use petroleum-based cleaning or sealing
compounds in boiler system. Severe damage to boiler
will result,causing substantial property damage.
Pre-installation
Boiler
model
number
Standard Fill-Trol tank
(for series loop or one-pipe system
with convector baseboard)
Additional Ex-Trol tank
(for cast-iron radiators or
cast-iron baseboard)
PER-15 No. 109 No. 15
PER-20 No. 109 No. 15
PER-25 No. 109 No. 15
Note: Gravity systems converted to a forced hot water system usually require
additional compression tank capacity.

Part number 550-141-396/0801
4
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Piping the boiler
Aftertheboiler is securedto thewall,attachthe supply
and return piping. Refer to Table 2 for minimum pipe
sizes.
Install manual shut-off valves in the supply and return
linestofacilitateservicingtheboiler. ModelPERboilers
areprovidedwithabuilt-inaireliminationsystemusing
a float-type automatic air vent. Refer to the boiler line
drawings and proceed as follows:
1. Installthe pressure-temperaturegaugeand¾"-¼"
bushing in the 1¼" x 1¼" x ¾" tee installed on the
boiler supply connection. See “Dimensions” on
page 12.
2. The ¾" tapping, located to the left of the supply
tapping, must be used for either an automatic
ventingdeviceorpipeddirectlytoastandardclosed
expansiontank.
3. Install the pressure relief valve in the ¾" tapping
located on the top left hand side of the boiler (see
“Dimensions” on page 12). Pipe the relief valve
outlettoafloordrainornearthefloor.Donotpipe
the relief valve to any area where freezing
temperatures might be encountered.
Pipe relief valve discharge line near
floorclosetofloordraintoeliminate
potential of severe burns. Do not
pipe to any area where freezing
could occur. Do not plug valve or
place any obstruction in discharge
line.
4. Connect the system supply piping to the tapping
locatedat theright on thetopof the boilercasting.
5. Connectthe systemreturn pipingtothecirculator
flange. When solder fittings are used, be sure that
thegasketisnotbetweentheflangeswhenthesolder
connection is made.
6. A Fill-Trol system is supplied with PER boilers
follow the instructions attached to the valve.
Pre-installation continued
Wiring the boiler
Electric shock hazard. Can cause
severe personal injury or death if
power source, including service
switchonboiler,isnotdisconnected
before installing or servicing.
TheModelPERelectric-hydronicboilersarepre-wired
for use with 240-volt,single phase, 50/60-hertz power.
Refer to Figure 1 on page 13 for the reduction in boiler
capacity when the line voltage is less than 240 volts.
Anopening isprovidedin theleft sideof thejackettop
panel for the field wiring. Refer to Dimensions, page
12, and Ratings, page 13, for recommended wire sizes.
All wiring must conform to the requirements of the
National Electrical Code and any additional National,
State or Local Code Requirements having jurisdiction.
All safety circuit wiring should be N.E.C. Class 1. Do
not use aluminum wire.
When a PER boiler is used in a zoned system, the zone
valves must be powered from an independent source,
and have electrically isolated end switches or isolating
relays wired in parallel to the boiler thermostat
terminals. Donotattempttopowerzonevalves
from the transformer in the boiler
control system.
Control system
The control system for the PER electric boiler has
electronicandthermaltimedelays,whichareemployed
to sequence elements on and to sequence elements off
in reverse order. The contactors used in the system
disconnect all current from the heating elements.
The circulator control utilizes a single pole relay.
Low and high limit functions are combined in a dual
limit control. The control system is operated from a
low voltage transformer.
Table 2 Pipe sizes and flow rates
(Recommended minimum pipe size with 20°F
temperature rise through boiler.)
Boiler
model
number
Maximum
flow rate
GPM
Minimum
supply
pipe size
Minimum
return
pipe size
PER-15 5.20 ¾" ¾"
PER-20 6.90 1" 1"
PER-25 8.60 1¼" 1¼"

Part number 550-141-396/0801 5
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Sequence of operation
Call for heat
1. The thermostat contacts close, energizing the first contactor (2K), the circulator relay
(1K), and the heater in the first thermal time delay (H1).
2. Approximately 15 seconds later, the thermal delay contacts (1C) close energizing the
electronic circuit inside the first electronic time delay (ED1).
3. After approximately 2.5 minutes, the first electronic time delay energizes the second
contactor (3K) and the second thermal time delay heater (H2).
4. This sequence continues until all contactors are energized or until the call for heat ends.
Call for heat satisfied
5. The thermostat contacts open,de-energizing the first contactor (2K),the circulator relay
(1K), and the heater in the first thermal time delay (H1).
6. Afteraminimumof10seconds,thecontactsinthefirstthermaldelay(1C)open,instantly
de-energizingtheelectronictimedelay(ED1),thesecondcontactor(3K),andthesecond
thermal delay heater (H2).
7. This sequence continues until all elements are de-energized.
Limit control operation
8. If the high limit setting is exceeded, the transformer secondary circuit is opened and all
contactorsarede-energizedinstantly. Itisrecommendedthatthe“high”sideofthecontrol
be set at 220°F. The“low”side should be set according to the design requirements of the
structure to be heated but never less than 20°F below the“high”setting. The differential
control should be set at a minimum of 20°F.

Part number 550-141-396/0801
6
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Wiring
Part Number 550-224-719/0801
Legend
HIGH VOLTAGE FACTORY WIRING LOW VOLTAGE FACTORY WIRING
HIGH VOLTAGE FIELD WIRING LOW VOLTAGE FIELD WIRING
A United Dominion Company
Weil-McLain • 500 Blaine St. • Michigan City, IN 46360-2388
Notes:
Items not provided
1.Thermostat heat anticipator setting must be 0.45 amps.
2.All wiring must be installed in accordance with the requirements of the National Electrical Code and any
applicable national, state or local code requirements.
3.All safety circuit wiring must be N.E.C. Class 1.
4.Use only copper conductors for power input wiring. Do not use aluminum conductors.
5.For 208-volt power supply, remove orange wire and replace with red wire.
6.Maximum circulator motor is 1/6 hp.
PER Series 3 15 KW thru 25 KW
240 VAC/single phase/60 hz
2½min. ON, 15 sec. OFF
OR
BB
RR
RD
BK
To
FUSES
CIRCULATOR
TRANSFORMER
TRANSFORMER
CIRCULATOR
EQUIPMENT
GROUND
Connect wire to
last fused terminal
WIRE
NUTS
WIRE
NUTS
Schematic Wiring Diagram
THERMOSTAT
OR END SWITCH
(Note 1)
(Note 6)
(Note 6)
Electrical shock hazard — can cause severe injury or
death. Disconnect power before installing or servicing.
1C
2C
4C
TD1 ED1
ED2
ED3
ED4
CONTACTORS
THERMAL TIME
DELAY RELAYS ELECTRONIC
TIME DELAY RELAYS HEATING
ELEMENTS
1K1 1K
TD2
TD3
TD4
H1
H2
H3 H4
2K1
2K
3K
4K
5K
6K
3K1
4K1
5K1
6K1
2K2
3K2
4K2
5K2
6K2
1
1
1
3
3
3
3
1
R
B
R
B
4
2
3
1
3C
L1
N
2K1
2K2
3K1
3K2
4K1
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
30 AMP
15 AMP
4K2
5K1
5K2
6K1
6K2
To:
To:
L2
(240 VAC)
THERMOSTAT
THERMOSTAT
24 VAC
24 VAC
HIGH
LIMIT
HIGH
LIMIT
LOW
LIMIT
LOW
LIMIT
THERMAL TIME
DELAY RELAYS
THERMAL TIME
DELAY RELAYS
ELECTRONIC TIME
DELAY RELAYS
ELECTRONIC TIME
DELAY RELAYS
Ladder Wiring Diagram
EQUIPMENT
GROUND
(Note 1)
F1
F2
F3
F4
F5
2K1
3K1
4K1
5K1
1K
2K
3K ED1
ED2
ED3
ED4
1C
2C
3C
4C
4K
5K
6K
H1
H2
H3
H4
6K1
2K2
3K2
4K2
5K2
6K2
F7
F8
F9
F10
F11
L1 L2 NG
G
F6 1K1
HIGH
LIMIT
HIGH
LIMIT
LOW
LIMIT
LOW
LIMIT
CIRCULATOR RELAY
CIRCULATOR RELAY
HEATING
ELEMENTS
(Note 5)

Part number 550-141-396/0801 7
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Troubleshooting
Symptom—No heat
1. Checkfuses. Powerforthecontrolcircuitissuppliedthroughthefuses
for the heating element,and the circulator.
2. Iffusesaregood,jumperthethermostatterminal. Ifboilerstarts,check
the thermostat and associated wiring.
3. If thermostat and wiring are good, check the limit control.
a. Jumperthe“R”and“B”terminalsonthe“low”sideofthecontrol.
If the boiler starts, replace the limit control.
b. Iftheboilerdoesnotstartinstep“a”,momentarilyjumperthe“R”
and“B”terminals on the“high”side of the control. If the boiler
starts, replace the limit control.
4. If the limit control is good,check the transformer.
a. MeasuretheA.C.voltageonthetransformer. IftheA.C.voltageis
24 volts ± 15%,the transformer is good.
b. If theA.C.voltage islow,removeone secondarylead from itsload
connection.
1) If the A.C.voltage returns to 24V,the transformer is good.
2) If theA.C.voltage remainslow,checkthe primary voltage. It
should measure 240 or 480 volts A.C.accordingly ± 10%. If
the primary voltage is correct,replace the transformer.
5. If the transformer is good, follow the voltage path using the wiring
diagram. Check each control for voltage in and out. Replace where
voltage fails.
Symptom—Low heat
Oneormorecontactorsdonotenergize. Operationofanycontactor,beyond
the first is dependent upon the operation of three components.
• Thermal time delay.
• Electronic time delay; 2½ minutes.
• Contactor.
1. Observe the sequence of operation and note at which contactor it is
interrupted. If onecontactorfails toenergize becauseof an opencoil,
subsequent contactors will be affected (unless one has a shorted coil).
To isolate the trouble,proceed as follows:
a. Check contactor. Connect a jumper from terminal 3 of the
electronic delay to the transformer wire going toterminal“B”on
the“low”side of the limit control.
b. If the contactor energizes check electronic and thermal delays.
Remove the jumper from the transformer terminal and touch it
to terminal 1 of the electronic delay. (The jumper now connects
terminals 1 and 3 of the electronic delay). If the contactor
energizes,replace the electronic time delay. If it fails to energize,
replace the thermal time delay.
Symptom—Boiler does not shut
down
One or more contactors remain on after call for heat
ends.
1. Check contactors. Lower the temperature setting
on“high”sideofthelimitcontroltosimulatealimit
operation.
a. If allcontactors instantlyde-energize,theyare
good.
b. If one or more contactors fail to de-energize,
replace those contactors.
2. If contactors are good, check the thermal delays.
Return the temperature setting on the“high”side
of the limit control to its original position. Allow
the boiler to sequence on with a normal call for
heat. When all contactorsareenergized,lower the
setting on the “low” side of the limit control to
satisfy the call for heat. Observe the shutdown
sequence and note the contactor at which it stops.
Remove the wire connecting terminal 1 of the
electronicdelaytothethermaldelay:Thecontactor
willnowde-energize,andtheremainingcontactors
willfollowinthenormaloffsequence. Replacethe
defective thermal delay.
Symptom—Inoperative
circulator
1. Measurethevoltageatthecirculatorterminalswith
theboiler energized. If thevoltageis 120V±10%,
thecontrolisgood. Ifnovoltageispresent,replace
the circulator relay (1K).
This boiler contains fiberglass materials. Use care when handling these materials per instructions on page 11 of
this manual.Failure to comply could result in severe personal injury.

Part number 550-141-396/0801
8
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Operating instructions
Water treatment
Do not use petroleum-based cleaning or sealing compounds in boiler
system. Severe damage to boiler will result, causing substantial property
damage.
Eliminate all leaks. Continual fresh makeup water will reduce boiler life.
Minerals can build up in section, reducing heat transfer, overheating cast
iron,and causing section failure.
Inhardwaterareas or lowpHconditions(below7.0),consultlocalwatertreatmentcompany.
Boiler water pH of 7.0 to 8.5 is recommended.
Filling the system with water
Never apply power to the boiler unless the boiler is filled with water.
1. Close manual air vents,drain cocks, and automatic air vent,if used.
2. Fill the boiler and system to an initial pressure of about 12 pounds per square inch.
3. Open automatic air vent one turn, if used.
4. Starting on the lowest floor, open air vents one at a time until water squirts out. Close
vent.
5. Repeat with remaining vents.
6. Refill to correct pressure.
Freeze protection (when used)
See WARNING on page 2 for important information regarding glycol hazard.
Do not use automotive, ethylene glycol or undiluted antifreeze. Severe
personal injury, death or substantial property damage can result.
Use antifreeze especially made for hydronic systems. Inhibited propylene glycol is
recommended.
50% solution provides protection to about -30°F.
Local codes may require a back-flow preventer or actual disconnect from city water supply.
Determine quantity according to system water content. Boiler water content is listed in the
Ratings table on page 13. Remember to add in expansion tank water content.

Part number 550-141-396/0801 9
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Checkout procedure
After filling and purging, start the boiler as follows:
❏Turn the thermostat to its lowest setting so that there is no call for
heat.
❏Set the limit control as recommendedin the Installation Instructions.
❏Turn on the main electric switch to the boiler.
❏Set the thermostat above actual room temperature.Check for proper
sequencing of elements.Heat the entire system to about 200°F so that
dissolvedairandgases in the systemwaterwillbe emittedandvented.
❏Check limit control operation by lowering the
control settings as described in the
“Troubleshooting”section on page 7.
❏Restore the limit control settings to their
recommendedvaluesandsetthethermostattothe
desired room temperature.
❏Fill in“Installation and service certificate”below.
❏If the boiler operates incorrectly or fails to start,
refer to“Troubleshooting”on page 7.
Boiler model __________________ Series __________ CP number ___________ Date installed _______________
Measured Btuh input ____________
Installer ________________________ ________________________________ ______________________________
(company) (address) (phone)
_____________________________________
(installer’s signature)
Installation and service certificate
❏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.

Part number 550-141-396/0801
10
PER Series 3 Electric-Hydronic Boilers Installation Instructions
Maintenance
Draining and cleaning
Do not drain the boiler during periods of shutdown
unless the heating system is exposed to freezing
temperatures. At the end of each heating season,open
the boiler drain cock just long enough to remove any
impurities or sediment that may have settled to the
bottom of the boiler.
Keeping air vent clean
Loosen the cap on the Float-Type Automatic Air Vent
two turns while the system is being filled with water.
Shoulddirt or scalelodgeonthevalveseatcausingitto
leak,removethe ventcap and push the valvecorein by
handtopermitwatertoflushthevalveseatclean;release
the valve core quickly and replace the vent cap. For
normaloperationand venting,unscrewthe ventcapat
least two turns.
Checking relief valve
Checkthe relief valveoncea year bymanually opening
thevalveandallowingasmallquantityofwatertoflow.
Make sure that the valve reseats and does not leak.
Replace any defective valve.
Checking expansion tank
Undersized expansion tanks cause
system water to be lost from relief
valve and makeup water added
through fill valve. Eventual section
failure can result.
If therelief valveopensfrequently,checkthe expansion
tank. Ifthesystemhasapressurizedtankwitharubber
diaphragm separating the air cushion from the water
(anEx-Trolorequivalenttank),useatirepressuregauge
to check the air-charging valve on the end of the tank.
If water flows, the diaphragm is ruptured or leaking.
Thetankmustbereplaced. Ifnowaterflowsbuttheair
charge has been lost, recharge the tank to 12 pounds
per square inch. Periodic air loss from the expansion
tank probably means a leaky charging valve.
If the expansion tank is of the standard closed variety,
(without a rubber diaphragm) the tank must be partly
drained to re-establish an air cushion.
Operating temperature and
pressure
The maximum recommended low and high limit
control settings are 200°F and 220°F, respectively. The
relief valve opens at 30 pounds per square inch. The
actual operating pressure will range from 12 pounds
per square inch when the system is cold to as much as
15 pounds per square inch at maximum operating
temperature.
Thisboilercontainsfiberglassmaterials.Usecarewhenhandlingthesematerialsperinstructions
on page 11 of this manual.Failure to comply could result in severe personal injury.