HydroTherm HVX User manual

HydroTherrw
HVX2-810
22-HVX2
m
fThis inanual s intended only fbl use byaqualified beating installer/technician Read and followthis manual, allsupplements and related
instructional infbrmation proxided with tile boiler. Install,start and ser;ice tile boiler only in tile sequence and inethods gixen illthese
instructions. Faihn:eto do so can result in sexere personal injury,death or substantial property damage.
Do not use the boiler during construction. Construction dust andparticulate,particularlydrywalldust,willcausecontamination of
the burner, resulting in possible sexere personal injury,death orsubstantial property damage. The boiler can only be operated with adust-
fi'eeair supply.Followthe instruction manual procedures to duct airto the boiler airintake. Ifthe boilerhas been contaminated byoperation
with contaminated air,fbllowthe instruction manual guidelines to clean,repair or replace the boiler ifnecessary.
Affixthese instructions near to the boile,,,'water heate, lnst, uct the buikting owner to retain the instructions ibr ihture use by aqualified
servicetechnician, and to fbllowallguidelines in the User's Infbrmation Manual.

INSTALLATION AND OPERATING INSTRUCTIONS
A. INSTALLATION SEQUENCE ....................... 2
B. SPECIAL ATTENTION BOXES ..................... 2
,,
A. ACCESSIBILITY CLEARANCES .................... 3
B. CLEARANCE FROM COMBUSTIBLE
CONSTRUCTION ................................ 3
C. AIR FOR COMBUSTION AND VENTILATION ......... 3
D. PLANNING THE LAYOUT ......................... 6
E. MASSACHUSETTS INSTALLATIONS ............... 6
i iiiiiili:i !! i iii:i i i Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii Ii ! ii! 7iii
A. GENERAL .................................... 30
B. DAILY (WITH BOILER IN USE) .................... 30
C. WEEKLY (WITH BOILER IN USE) .................. 31
D. MONTHLY (WITH BOILER IN USE) ................ 31
E. ANNUALLY (BEFORE START OF HEATING
SEASON) ..................................... 31
A. BLOCK/BASE/FLOOR PAN
JACKET/FLUE COLLECTOR ...................... 33
B. BASE/BURNERS/MANIFOLD ..................... 34
A. BOILER SUPPLY AND RETURN .................... 8
B. SAFETY RELIEF VALVE .......................... 9
C. PIPING FOR ZONED SYSTEMS ................... 10
D. EXPANSION TANK ............................. 11
E. INDIRECT-FIRED WATER HEATER ................. 11
E FREEZE PROTECTION .......................... 11
f:ll II_!.'tq.'lli!.'l/[o]_l _.'];[o].lJ!_[o,]!
A. GENERAL .................................... 12
B. CHIMNEY VENTING ............................ 12
C. DIRECT EXHAUST HORIZONTAL VENTING ......... 12
D. DIRECT EXHAUST VERTICAL VENTING ............ 15
E. BOILER REMOVAL FROM
COMMON VENTING SYSTEM .................... 16
Follow the installation instructions provided in this
manual in the order shown. The order of these
instructions has been set in order to provide the
installer with a logical sequence of steps that will
minimizepotential interferences and maximize safety
during boiler installation.
I:!1 [,-l'.l:l:l]llllfll//!_i/[o]_l I:{o):t_ _7
Throughout this manual you will see special attention
boxes intended to supplement the instructions and
make special notice of potential hazards. These
categories mean, in the judgment of the manufacturer:
A. WIRING ...................................... 19
B. ZONED SYSTEM WIRING ....................... 19
C. CONTROLS ................................... 19
D. SEQUENCE OF OPERATION ..................... 20
Indicates a condition or hazard which will cause
severe personal injury, death or major property
damage.
A. COMPLETING THE INSTALLATION ................ 23
B. CONTROL DESCRIPTIONS ....................... 25
C. ADJUSTMENT OF GAS PRESSURE REGULATOR .... 25
D. CHECKING BURNER INPUT ...................... 25
E. CHECK-OUT PROCEDURE ....................... 25
Indicates a condition or hazard which may cause
severe personal injury, death or major property
damage.
A. SHUT-DOWN CAUSED BY PILOT OUTAGE,
PRESSURE SWITCH OR FLAME ROLL-OUT
SAFETY SHUT-OFF SWITCH ..................... 27
B. TROUBLESHOOTING GUIDES .................... 27
C. MEASURING SUCTION PRESSURE ............... 27
Indicates a condition or hazard which will or can
cause minor personal injury or property damage.
Indicates special attention is needed, but not directly
related to potential personal injury or property
damage.
2

INSTALLATION AND OPERATING INSTRUCTIONS
Read carefully, study these instructions before beginning work.
This boiler must be installed by a qualified contractor.
The boiler warranty can be voided if the boiler is not installed, maintained and serviced correctly.
The equipment must be installed in accordance with those installation requirements of the authority having
jurisdiction or, in the absence of such requirements, to the current edition of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and/or CAN/CSA B149.1, Natural Gas and Propane Installation Code.
Where required by the authority having jurisdiction, the installation must conform to American Society of
Mechanical Engineers Safety Code for Controls and Safety Devices for Automatically Fired Boilers,
ANSI/ASME CSD-I.
7._I V.'I_H _'_11:] I!/L'd[_]! =!'.'I:!.'I _[_]_1
Install boiler not less than 24" (610 mm) between the
left side, top, and front of the boiler and adjacent wall or
other appliance, when access is required for servicing.
The design of this boiler is certified for closet installation
with the following clearances:
1. 6" (152 mm) between sides, rear and front and
combustible construction.
2. 24" (610 mm)between top of jacket and
combustible construction.
3. 2" (51 mm) between vent pipe and combustible
construction.
Do not install this boiler on combustible flooring
unless it is installed on a special combustible floor
pan provided by the manufacturer. Boiler installation
on combustible flooring without the special pan is a
fire hazard.
To order combustible floor pan, use the 5-digit stock
codes listed in Section 11 of this manual.
Do not install this boiler on carpeting. Boiler
installation on carpeting is a fire hazard. Install this
boiler on non-combustible flooring or use a
combustible floor pan to install this boiler on other
non-carpeted flooring.
1.
2.
Adequate combustion air and ventilation air must be
provided in accordance with section 5.3, Air for
Combustion and Ventilation, of the National Fuel
Gas Code, ANSI Z223.1/NFPA 54, or Sections 7.2,
7.3 or 7.4 of CAN/CSA B149.1, Natural Gas and
Propane Installation Code or applicable provisions of
the local building code. Subsections 2 through 8 as
follows are based on the National Fuel Gas Code
requirements.
Required Combustion Air Volume: The total required
volume of indoor air is to be the sum of the required
volumes for all appliances located within the space.
Rooms communicating directly with the space in
which the appliances are installed and through
combustion air openings sized as indicated in
Subsection 3 are considered part of the required
volume. The required volume of indoor air is to be
determined by one of two methods.
a. Standard Method: The minimum required
volume of indoor air (room volume) shall be 50
cubic feet per 1000 BTU/Hr (4.8 m3/kW). This
method is to be used if the air infiltration rate is
unknown or if the rate of air infiltration is known
to be greater than 0.6 air changes per hour. As
an option, this method may be used if the air
infiltration rate is known to be between 0.6 and
0.4 air changes per hour. If the air infiltration rate
is known to be below 0.4 then the Known Air
Infiltration Rate Method must be used. If the
building in which this appliance is to be installed
is unusually tight, we recommend that the air
infiltration rate be determined.
b. Known Air Infiltration Rate Method: Where
the air infiltration rate of a structure is known, the
minimum required volume of indoor air for the
boiler and other fan assisted appliances shall be
determined as follows:
Required Volumerar7i15 ft3 /rat7
AC H 1o00BtU/hr

INSTALLATION AND OPERATING INSTRUCTIONS
3.
4
Figure 1.1 :
where:
It_n = Input of the fan assisted appliances in
Btu/hr
ACH = air change per hour (percent of the
volume of the space exchanged per
hour, expressed as a decimal)
For appliances other than fan assisted, calculate
the required volume of air using the following
equation:
21 ft-s Iother
Required Volumeother = ACH lO00BtU/hr
Iother =Input of appliances other than fan
assisted in Btu/hr
Note: These calculations are not to be used for
infiltration rates greater than 0.60 ACH.
Indoor Air Openinq Size and Location: Openings
connecting indoor spaces shall be sized and located
as follows:
a. Combining spaces on the same floor:
Provide two permanent openings communicating
with additional spaces that have a minimum free
area of 1 in2 per 1000 Btu/hr (22 cm 2 per 1000 W)
of the total input rating of all gas fired equipment
but not less than 100 in 2 (645 cm2). One
opening is to begin within 12 inches (305 mm)
from the top of the space and the other is to
begin within 12 inches (305 mm) from the floor.
The minimum dimension of either of these
openings shall be 3 inches (76 mm). See Figure
1.1 for an illustration of this arrangement.
TWO AIR OPENINGS:
Minimum
Free Area Each
1 in 2 per 1000 Btuh
(22 errF per 1000 W)
at Least 100 in 2
(645 cm 2 )
b.
12" (305mrs')
m(lx
s" (Turin)
min
BUILDING
(SPACES ON
SAME STOU)
Must not be under
negative pressure
3" (76ram)
rain
12" 505rr r_')max
Air Openings - All Air from Indoors
on the Same Floor
Combining spaces on different floors:
Provide one or more permanent openings
communicating with additional spaces that have
a total minimum free area of 2 in2 per 1000
Btu/hr (44 cm 2 per 1000 W) of total input rating
of all equipment. See Figure 1.2 for an
illustration of this arrangement.
Figure 1.2:
4.
12" (505rr'm)maxi
Air Openings - All Air from Indoors
on Different Floors
Outdoor Combustion Air: Outdoor combustion air is
to be provided through one or two permanent
openings. The minimum dimension of these air
openings is 3 inches (76 mm).
a. Two Permanent Opening Method: Provide
two permanent openings. One opening is to
begin within 12 inches (305 mm) of the top of
the space and the other is to begin within 12
inches (305 mm) of the floor. The openings are
to communicate directly or by ducts with the
outdoors or with spaces that freely communicate
with the outdoors. The size of the openings shall
be determined as follows:
3" (76rnm)
rain
12" (305ram)
too×
Figure 1.3:
Where communicating directly or through
vertical ducts with the outdoors each opening
shall have a minimum free area of 1 in 2 per
4000 Btu/hr (22 cm 2 per 4000 W) of total
input rating for all equipment in the space.
See Figure 1.3 for openings directly
communicating with the outdoors or Figure
1.4 for openings connected by ducts to the
outdoors.
\\,
\ \,
........iiiiiiii
Air Openings - All Air Directly from
Outdoors
4

INSTALLATION AND OPERATING INSTRUCTIONS
12" (505r r)rax I
z
(
MINIM JM
CLEARANCES:
" (P r/r ) Fr rY
_ides qrd back
6" (/5( rYr 0
frorr frort
Figure 1.4:
ii,
12" (:SO5r r)r_ax I
Figure 1.5:
Air Openings - All Air from Outdoors
through Vertical Ducts
b.
Where communicating with the outdoors
through horizontal ducts, each opening shall
have a minimum free area of 1 in 2 per 2000
Btu/hr (22 cm 2 per 2000 W) of total rated
input for all appliances in the space. See
Figure 1.5.
Air Openings - All Air from Outdoors
through Horizontal Ducts
One Permanent Opening Method: Provide
one permanent opening beginning within 12
inches (305 mm) of the top of the space. The
opening shall communicate directly with the
outdoors, communicate through a vertical or
horizontal duct, or communicate with a space
that freely communicates with the outdoors. The
openings shall have a minimum free area of 1 in 2
per 3000 Btu/hr of total rated input for all
appliances in the space and not less than the
sum of the cross-sectional areas of all vent
connectors in the space. The gas fired equipment
shall have clearances of at least 1 inch (25 mm)
from the sides and back and 6 inches (150 mm)
from the front of the appliance. See Figure 1.6
for this arrangement.
Figure 1.6: Air Openings - All Air from Outdoors
through One Opening
5. Combination Indoor and Outdoor Combustion Air:
If the required volume of indoor air exceeds the
available indoor air volume, outdoor air openings or
ducts may be used to supplement the available
indoor air provided:
a. The size and location of the indoor openings
comply with Subsection 3.
b. The outdoor openings are to be located in
accordance with Subsection 4.
c. The size of the outdoor openings are to be sized
as follows:
Vavail
A,-eq=A_u// x 1- V,eq
where:
Areq = minimum area of outdoor openings.
Atull = full size of outdoor openings calculated
in accordance with Subsection 4,
V_vail = available indoor air volume
Vreq = required indoor air volume
6. Engineered Installations: Engineered combustion air
installations shall provide an adequate supply of
combustion, ventilation, and dilution air and shall be
approved by the authority having jurisdiction.
7. Mechanical Combustion Air Supply:
a. In installations where all combustion air is
provided by a mechanical air supply system, the
combustion air shall be supplied from the
outdoors at the minimum rate of 0.35 ftS/min per
1000 Btu/hr (0.034 mS/min per 1000 W) of the
total rated input of all appliances in the space.
b. In installations where exhaust fans are installed,
additional air shall be provided to replace the
exhaust air.

INSTALLATION AND OPERATING INSTRUCTIONS
8.
I,]il I',ji_':_l_ll_[_//:l:! I!':VL*IIJd
I_ hv_P';T,."_"]P';[o,]'LU_")_/n_Ih_(,."]iq±_iUlip'±_id[o]_(,."]
9.
d.
Each of the appliances served shall be
interlocked to the mechanical air supply to
prevent main burner operation where the
mechanical air supply system is not in operation.
In buildings where the combustion air is provided
by the mechanical ventilation system, the system
shall provide the specified combustion air rate in
addition to the required ventilation air.
Louvers & Grills:
a. The required size of openings for combustion,
ventilation, and dilution air shall be based on the
net free area of each opening.
Where the free area through a louver or grille
is known, it shall be used in calculating the
opening size required to provide the free area
specified.
ii. Where the free area through a louver or grille
is not known, it shall be assumed that wooden
louvers will have 25% free area and metal
louvers and grilles will have 75% free area.
iii. Nonmotorized dampers shall be fixed in the
open position.
b. Motorized dampers shall be interlocked with the
equipment so that they are proven in the full
open position prior to ignition and during
operation of the main burner.
i. The interlock shall prevent the main burner
from igniting if the damper fails to open
during burner startup.
ii. The interlock shall shut down the burner if
the damper closes during burner operation.
Combustion Air Ducts:
a. Ducts shall be constructed of galvanized steel or
an equivalent corrosion- resistant material.
b.
c.
d.
Ducts shall terminate in an unobstructed space,
allowing free movement of combustion air to the
appliances.
Ducts shall serve a single space.
Ducts shall not serve both upper and lower
combustion air openings where both such
openings are used. The separation between ducts
serving upper and lower combustion air
openings shall be maintained to the source of
combustion air.
Ducts shall not be screened where terminating in
an attic space.
Horizontal upper combustion air ducts shall not
slope downward toward the source of the
combustion air.
g.
h.
The remaining space surrounding a chimney
liner, gas vent, special gas vent, or plastic piping
installed within a masonry, metal, or factory built
chimney shall not be used to supply combustion
air.
Combustion air intake openings located on the
exterior of buildings shall have the lowest side of
the combustion air intake opening at least 12
inches (305 mm) above grade.
Liquefied Petroleum (LP) is heavier than air and may
collect or "pool" in a low area in the event of a leak
from defective equipment. This gas may then ignite,
resulting in a fire or explosion.
Prepare sketches and notes of the layout to minimize the
possibility of interferences with new or existing
equipment, piping, venting and wiring.
Massachusetts requires manufacturers of Side Wall
Vented boilers to provide the following information
from the Massachusetts code:
• A hard wired carbon monoxide detector with an
alarm and battery back-up must be installed on
the floor level where the gas equipment is to be
installed AND on each additional level of the
dwelling, building or structure served by the side
wall horizontal vented gas fueled equipment.
• In the event that the side wall horizontally vented
gas fueled equipment is installed in a crawl space
or an attic, the hard wired carbon monoxide
detector with alarm and battery back-up may be
installed on the next adjacent floor level.
• Detedor(s) must be installed by qualified licensed
professionals.
•APPROVED CARBON MONOXIDE
DETECTORS: Each carbon monoxide detector
shall comply with NFPA 720 and be ANSI/UL
2034 listed and IAS certified.
• SIGNAGE: A metal or plastic identification plate
shall be permanently mounted to the exterior of
the building at a minimum height of eight (8) feet
above grade directly in line with the exhaust vent
terminal for the horizontally vented gas fueled
heating appliance or equipment. The sign shall
read, in print size no less than one-half (1/2) inch
in size, "GAS VENT DIRECTLY BELOW.
KEEP CLEAR OF ALL OBSTRUCTIONS".
6

INSTALLATION AND OPERATING INSTRUCTIONS
EXEMPTIONS to the requirements listed above:
o The above requirements do not apply if the
exhaust vent termination is seven (7) feet or
more above finished grade in the area of the
venting, including but not limited to decks
and porches.
o The above requirements do not apply to a
boiler installed in a room or structure separate
from the dwelling, building or structure used
in whole or in part for residential purposes.
See the latest edition of Massachusetts Code
248 CMR for complete verbage and also for
additional (non-vent related) requirements
(248 CMR is available online).
If your installation is NOT in Massachusetts, please
see your authority of jurisdiction for requirements
that may be in effect in your area. In the absence of
such requirements, follow the National Fuel Gas
Code, ANSI Z223.1/NFPA 54 and/or CAN/CSA
B149.1, Natural Gas and Propane Installation Code.
Venting System Installation Instructions - See
boiler manual and instructions provided with the
Venting System components. Additional copies may
be obtained from the Venting System Manufacturer
by visiting the following web addresses:
Heat-Fab - www.selkirkcorp.com/heatfab
Z-Flex - www.NovaFlex.com
Pro-Tech - www.protechinfo.com
MetaI-Fab - www.rntlfab.com
1.
2.
3.
Provide a sound, level foundation. Locate boiler as
near to the chimney or outside wall as possible and
centralized with respect to the heating system.
Locate boiler in front of installation position before
removing crate.
If using combustible floor pan, position pan on
foundation or flooring.
4.
5.
Separate the wood shipping pallet from the boiler
base by removing two (2) hold-down bolts at each
end of the boiler base.
Move boiler into final position. If using combustible
floor pan, install boiler on pan as outlined in the
instructions included with the pan.

INSTALLATION AND OPERATING INSTRUCTIONS
f.'1 I:{=] I I!=1:| [_llJ d d li'AV.'I_I=]I:_=l |lJ :__I
1.
2.
Size the supply and return to suit the system. A
typical piping arrangement is shown in Figure 3.1.
Refer also to the I=B=R Guide to Residential
Hydronic Heating Installation/Design for additional
guidance during water piping installation.
Return Piping:
a. Pipe the outlet connection of the circulator to a
tee, provided with a drain valve, at the 1-1/4
NPT return tapping near the bottom of the left
section. Pipe the return to the inlet connection of
the circulator.
3.
4.
5.
Supply Piping:
Pipe the supply to the 1-1/2 NPT supply tapping at
the top of the boiler.
When system return water temperature will be below
130°F (54°C), pipe the boiler with a bypass
arrangement to blend the system return and hot
supply to obtain at least 130°F (54°C) entering the
boiler.
If desired, install the circulator in the alternate
location shown in Figure 3.1.
ELIMINATOR
_AFETYRELIEFVALVE
SUPPLY
COLD
£R
SHUTOFF
PRESSUREREDUCING
CHECK
SHUTOFFVALVE
EXPANSION TANK
Figure 3.1: Supply and Return Piping
8

INSTALLATION AND OPERATING INSTRUCTIONS
6.
7.
8.
9.
Install this boiler so that the gas ignition system
components are protected from water (dripping,
spraying, etc.) during appliance operation and
service (circulator replacement, condensate trap,
control replacements, etc.).
If this boiler and distribution system is used in
conjunction with a refrigeration system, pipe the
chilled medium in parallel with the boiler and install
the proper valve to prevent the chilled medium from
entering the boiler. A drawing illustrating this hook-
up is provided in Figure 3.2.
When the boiler is connected to heating coils located
in air handling units where they may be exposed to
refrigerated air circulation, install flow control valves
or other automatic means to prevent gravity
circulation of the boiler water during the cooling
cycle.
If this boiler is installed above radiation level,
provide a low water cutoff device, either as a part of
the boiler or at the time of boiler installation.
I:]! [,,._.qgl=il,',dI:_=lltll=lglkV/.qlkVj=l
1. Locate safety relief valve and fittings in bag
assembly.
2. If air elimination is not required at the safety relief
valve tapping, install valve and piping as shown in
Figure 3.3.
3. For air elimination at the safety relief valve tapping,
install valve and piping as shown in Figure 3.4.
Pipe the discharge of safety relief valve to prevent
injury in the event of pressure relief. Pipe the
discharge to a drain. Provide piping that is the same
size as the safety relief valve outlet.
CHECK VAL:VE--. ,\
SL PPLY -,
TO DRAII
....... SAFETY
RELIEF
'iALVE
\
\
/
/
f_- -
/
Figure 3.3:
U1:FL Y
SAFETY
RELIEF
vALVE --.
Safety Relief Valve Hook-Up
Installation with Air Elimination in
System Piping
TO '_,IR
ELI qlX ,_TION
DEVICE
/3/4" TEE
3,/4" X _"
N I _: LE
/_/'q" X2"
NIPPLE
ELB0 ,_v \ ..... .
/
/
/
J
/
Figure 3.4: Safety Relief Valve Hook-Up with
Air Elimination
LNE
WAT ER THR_Eo WAY
VALVE
Figure 3.2: Parallel Hook-up with Water Chiller

INSTALLATION AND OPERATING INSTRUCTIONS
1.
2.
3.
See Figures 3.5 and 3.6 for basic zoned system
layouts.
Run each zone pipe down then up to zone to
prevent air accumulation in piping.
If required, provide means to isolate and drain each
zone separately.
TO SYSTEM
ZONE ZONE
3 2
VALVES
B-_ I CHECK
TO BYPASS VALVE
CITY WATER
SHUTOFF VALVE
PRESSURE REGULATOR
ZONE
1
FROM SYSTEM
ZONE ZONE ZONE
1 2 5
SYSTEM
CIRCULATOR
CONNECT
TO
SUPPLY
BALANCING ,
VALVES H, _-
CONNECT TO
RETURN
FROM
EXPANSION TANK
BYPASS
Figure 3.5: Zone Piping with Zone Valves
FROM SYSTEM
ZONE ZONE ZONE
1 2 5
ZONE
CIRCULATORS
CHECK VALVE
CITY WATER
SHUTOFF VALVE
PRESSURE REGULATOR
CONNECT
TO
SUPPLY
TO SYSTEM
ZONE ZONE
3 2
FLOW
CONTROL
VALVES
CONNECT TO
RETURN
TAPPING
!ZONE
1
t
EXPANSION TANK
Figure 3.6: Zone Piping with Circulators
10

INSTALLATION AND OPERATING INSTRUCTIONS
II1_1!:I'I ! ".1f(,l i :(,.i i [,] _IOI 1:13".1.'I_q,.'][.] _Ii L'I _H3
1, Consult the tank manufacturer's instructions for
specific information relating to tank installation. Size
the expansion tank for the required system volume
and capacity. See Table 10.2 in Section 10 for boiler
water capacity.
2. Expansion tanks are available with built-in fill valves
and check valves for reducing supply water pressure
and maintaining minimum system pressure. Check
the design features of the tank and provide valves as
necessary.
Refer back to Figure 3.1 for typical expansion tank piping.
:II IhH,] 1:1:(.i ,'li 1:1!,] iviv/.,l/! :I I: I:/.,1i ! :1
If the boiler is to be used in conjunction with an indirect-
fired water heater, refer to Figure 3.7 for typical piping.
Follow the instructions provided by the water heater
manufacturer. Pipe the water heater as a separate zone.
For new or existing systems that must be freeze-
protected:
Use only inhibited propylene glycol solutions of up to
50% by volume with water. Ethylene glycol is toxic
and can attack gaskets and seals used in hydronic
systems.
1,
2,
3,
Glycol in hydronic applications is specially
formulated for this purpose. It includes inhibitors
which prevent the glycol from attacking metallic
system components. Make certain that the system
fluid is checked for the correct glycol concentration
and inhibitor level.
The antifreeze solution should be tested at least once
a year and as recommended by the antifreeze
manufacturer.
Antifreeze solutions expand more than water. For
example, a 50% by volume solution expands 4.8%
in volume for a temperature increase from 32°F
(O°C) to 180°F (82°C), while water expands 3% with
the same temperature rise. Allowance must be made
for this expansion in system design.
SUPPLY TO
SYSTEM
RETURN FROM
SYSTEM
HOT DOMES'I'IC
WATER
SUPPLY
COLD
DOMESTIC
WATER SUPPLY
ZONE VALVES
INDIRECT=FIRED
WATER
HEATER
SUPPLY
TO
TANK
BALANCING
VALVE
SYSTEM
CIRCULATOR
EXPANSION
TANK
SHUTOFF
VALVE
BALANCING
VALVE:
DRAIN
CHECK
VALVE
SHUTOFF
VALVE
PRESSURE
REGULATOR
COLD
-- WATER
FILL
Figure 3.7: Typical Piping with Indirect-Fired Water Heater
11

INSTALLATION AND OPERATING INSTRUCTIONS
I'.'I [*] :1_1:1:!.q !
1,
2,
3,
Install vent system in accordance with the "Venting of
Equipment" Chapter of the National Fuel Gas Code,
ANSI Z223.1/NFPA 54, the "Venting Systems and Air
Supply for Appliances" Section of the CAN/CSA
B149.1, Natural Gas and Propane Installation Code.
or applicable provisions of the local building codes.
Do not connect vent connectors serving appliances
vented by natural draft into any portion of
mechanical draft systems operating under positive
pressure.
Refer to the following venting options to determine
which method is applicable.
All joints of positive pressure vent systems must be
sealed completely to prevent leakage of flue products
into the living space.
2,
3,
4,
5,
Horizontal portions of the venting system shall slope
upward at least 1/4" per lineal foot (21 mm per
meter) between boiler and chimney. The vent pipe
shall be supported to prevent sagging; using metal
strapping or equivalent means at no more than 4 ft.
(1.2 meter) intervals.
Locate fan adapter, silicone, hardware and fan
adapter gasket in boiler miscellaneous parts box
and attach to blower outlet flange. Refer to Fig. 4.1
for details.
Apply 1/4" (6 mm) bead of silicone around fan
adapter and slip increaser over the fan adapter. Refer
to Table 4.1 for increaser and chimney sizes.
Increaser to be provided by installer.
Single wall vent pipe should be furnished between
increaser and chimney. If the vent connector shall be
located in or pass through a cold area, the vent
connector shall be type B material.
I:]q [H" II_vJ_H:4"dkvA:__i / h_It]
If venting into a masonry chimney; chimney must be
lined with a fire clay tile liner or corrosion resistant metal
liner. Type B vent may also be used as a lining system or
as a stand alone chimney vent.
1. The vent system, when installed per the following
instructions, will operate with a negative pressure (draft).
Flue gases will condense as they exit the vent
termination. This condensate can freeze on exterior
building surfaces which may cause discoloration of
these surfaces.
Table 4.1 : Increaser & Chimney Size
Boiler Increaser Size Vent Size Chimney
Size Diameter Height
70 3" to 4" (7.6 to 10.2 cm) 4" (10.2 cm) 15' (4.5 m)
105 3" to 5" (7.6 to 12.7 cm) 5" (12.7 cm) 15' (4.5 m)
140 3" to 5" (7.6 to 12.7 cm) 5" (12.7 cm) 15' (4.5 m)
165 3" to 5" (7.6 to 12.7 cm) 5" (12.7 cm) 15' (4.5 m)
1, This vent system will operate with a positive pressure
in the vent pipe. Follow vent pipe manufacturers
instructions for proper assembly of vent pipe and
fittings.
Figure 4.1 :
SLOPE UP 1/4" r/f_
PER FOOT
SLOPE UP /4" _ ...... ----q _ "_ I
PER FOOT _
E2O.... PER METER] \ H _
JACKET PANELS _ / " _" 1
Fi X ADAPTER\ I_ , 4 ] -. I
FAN ADAPTER CASKET // ILl _-NI; CREASER _
1/420NUTS/S CO ,_
Chimney Venting
12

INSTALLATION AND OPERATING INSTRUCTIONS
2.
3.
4.
5.
6.
Refer to Table 4.2 for minimum and maximum vent
length allowed.
Maintain a minimum 2" (51 mm) clearance between
vent pipe and combustible construction.
When installing vent pipe through a combustible
wall, pipe must pass through a metal wall thimble;
maintain a 2" (51 mm) clearance between vent pipe
and thimble. Follow thimble manufacturer's
instructions. Seal between thimble and exterior wall
using exterior-rated caulk or silicone to prevent water
damage and also to prevent recirculation of flue
products into the structure.
Determine vent terminal location.
a. Vent terminal shall be located at least 3 feet (1
meter) above any forced air inlet located within
10 feet (3 meters).
b.
d.
Vent terminal shall be located at least 4 feet (1.2
meters) below, 4 feet (1.2 meters) horizontally
from, or 1 foot (0.3 meters) above any door,
window, or gravity air inlet into any building.
Vent terminal shall be located at least 1 foot (0.3
meters) above ground level or normal snow lines.
See subsection 7 below if terminal needs to be
extended above ground level or snow line.
Vent terminal shall not be located over public
walkways where condensate could create a
nuisance or hazard.
When adjacent to a public walkway, vent
terminal shall be at least 7 feet (2.1 meters)
above grade.
Vent terminal shall be located at least 4 feet (1.2
meters) horizontally from electric meters, gas
meters, regulators and relief equipment. In
Canada, this dimension must be 6 feet (2 meters).
Vent terminal should not be located directly
under roof overhangs to prevent icicles from
forming.
Vent Pipe Assembly:
a. Horizontal portions of the vent pipe shall slope
down not less than 1/4" per foot (21 mm per
meter) from the boiler to the vent termination
elbow. If this horizontal run is pitched toward
boiler, provide a horizontal drain tee as per
instructions in section D. Direct Exhaust;
Vertical Venting.
b. Secure vent pipe using metal strapping, clamps
and/or other means. Do not screw into the vent
pipe.
•Horizontal portions of the vent pipe must be
supported at intervals no greater than four
feet to prevent sagging/separation.
• Secure vent pipe to the thimble/wall to
prevent possible movement from incidental
contact on the vent terminal.
d.
e.
g.
h.
Type vent material approved is AL29-4C, 3 inch
(76 mm) diameter stainless steel; manufactured
by Heat-Fab <_(Saf-T-Vent); Z-Flex <_(Z-Vent);
ProTech (FasNSealT"); Flex-L (StaR-34); Metal-
Fab (Corr/Guard).
Attach the fan adapter to blower outlet flange
using gasket and 1/4" (6 mm) -20 nuts and
washers, (parts located in miscellaneous parts
box).
Refer to Figure 4.3 that lists special vent adapters
for connection to boiler fan adapter. These
special adapters are not supplied with boiler.
Attach vent pipe adapter to boiler fan adapter by
applying a 1/4" (6 mm) bead of high
temperature silicone around diameter of fan
adapter and slip vent pipe adapter over the fan
adapter. Fill in any voids with silicone and
smooth out with moistened finger or flat tool.
If using Z-Flex _' pipe, slide vent pipe over the first
2-1/2" (64 mm) of the fan adapter and secure
joint connection with the Z-Flex (_looking bands
making sure that locking band has contact with
fan adapter at boiler end and vent pipe.
Attach remaining pipe and fittings per
manufacturer's vent instructions. Use only the
silicone recommended by the vent pipe
manufacturer.
i. The only approved vent termination is a 3" (76
mm) 90 ° elbow. Refer to Figure 4.4. Vent pipe
must be sealed to the thimble (or outside wall if-
non-combustible construction) using silicone to
prevent recirculation of flue products into the
structure.
Table 4.2.: Equivalent Vent Length
*Equivalent Length of 3" diameter
Boiler Stainless Steel Vent Pipe
Size Minimum Vent Length Maximum Vent Length
70 2-1/2 feet (762 m) 50 feet (15 m)
105 2-1/2 feet (762 m) 50 feet (15 m)
140 2-1/2 feet (762 m) 45 feet (13.7 m)
165 2-1/2 feet (762 m) 45 feet (13.7 m)
_Maximum Vent Length to be reduced by 5 feet (1.5
meters) for each 90° elbow added that is
manufactured by Z-Flex% Heat-Fab (_and Protech.
_Maximum Vent Length to be reduced by 7-1/2 feet
(2.3 meters) for each 90° elbow added that is
manufactured by Flex-h
The outside vent terminal (90 ° Elbow) is not
included in Equivalent Vent Length.
7. Refer to Figure 4.2 for vertical offset option. The
maximum offset is 5 feet. With the exception of the
last 90 ° elbow which serves as the vent terminal, the
additional elbows and straight vent pipe must be
considered when determining maximum vent length.
Provide a horizontal drain tee as described in
Section D. Direct Exhaust; Vertical Venting.
13

INSTALLATION AND OPERATING INSTRUCTIONS
(WALL TO CENTERLINE
8_' M_N OF VENTTERM_NAI)
2" MIN.
(EDGE OF PiPE TO
COMBUSTIBLE WALL}
90 ELBOW
BRACKET
5 MAX.
SLOPE PIPE
TOWARDS
BOILER .... _ ........
SEAL WALL
PENETRATION
(INCLUDING THIMBLE
WHERE USED
90 ° ELBOW
VENT
TERMINATION
_ 90" ELBOW'
DRAIN TEE REQUIRED.
SEE INSIRUC lIONS.
Figure 4.2: Direct Exhaust, Sidewall Venting with Vertical Off-Set
_ Z-FLEX
Z-VENT F-HEAT-FAB [- PROTECH F FLEX-L
/)PIPE. iC:x'_l /VENT PIPE, VENT PIPE,
MALE END MALE END MALE END
/Z-FLEX HEAT-FAB PROTECH FLEX-L
Z-VENT SAF-T VENT ;FASNSEAL ;STAR-34
LOCKING 7301 AMTK FSA-PSC/DE-3 SRAPPA3
BAND VENT ADAPTER VENT ADAPTER VENT ADAPTER
SVSLBX03
Z
1/4" BEAD 1/4" BEAD 1/4" BEAD
SILICONE 7SILICONE 7 SILICONE
FAN ADAPTER
1/4" BEAD
L FAN ADAPTER FAN ADAPTER FAN ADAPTER
METAL-FAB
CORR/GUARD
VENT PIPE,
MALE END
METAL-FAB
3CGBA2
VENT ADAPTER
FAN ADAPTER
Figure 4.3: Vent Pipe Adapters
14

INSTALLATION AND OPERATING INSTRUCTIONS
SECURING VENT PiPE
TO THIMB
WALL THIMBLE
SLOPE DOWN
1/4" PER FOOT
[2Omm PER METER]
Figure 4.4:
JACKET PANELS-_
FAN
FAN ADAPTER GASKET
1/4-20 NUTS
& WASHERS
FAN
ADAPTER
r"'---"l E
L__J
VENT PIPE
ADAPTER
(SEE VENT PIPE
ADAPTER LISTING)
SILICONE
Direct Exhaust; Sidewall Venting
COMBUSTIBLE
EXTERIOR WALL
CAULK OR SILICONE
SILICONE
2"
[51mm] MIN.
CLEARANCE
90" ELBOW
VENT TERMINATION
8"
[205mm]
5" DIAo VENT PIPE
"_ SEAL JOINTS PER VENT
MANUFACTURER'S INSTRUCTIONS
D]IIID]I'|_I/ 1_24-"¥±UII.."]II_lIlJ_l,ll/[_l'_'111lJ_l_l/h_[e_
1.
2.
3.
4.
This vent system will operate with a positive pressure
in the vent pipe. Follow vent pipe manufacturer's
instructions for proper assembly of vent pipe and
fittings.
Refer to Table 4.2 for minimum and maximum vent
length allowed.
Maintain a minimum 2" (51 mm) clearance between
vent pipe and combustible construction.
Follow instructions under section C. DIRECT
EXHAUST; HORIZONTAL VENTING items 6b
through 6h.
5.
6.
7.
8.
Horizontal portions of the vent pipe shall slope up
not less than 1/4" per foot (21 mm per meter) from
the boiler to the vertical vent.
Provide a horizontal drain tee in the horizontal vent
run. Use silicone drain hose with a 3" (76 mm)
diameter loop trap with a water seal. Pipe to drain
per local codes.
Refer to vent pipe manufacturer's instructions under
vertical venting section for recommendation for
penetration through floors and roofs.
Vent must terminate 12" (305 mm) above expected
snow lines.
9. See Figure 4.5 for details.
15

INSTALLATION AND OPERATING INSTRUCTIONS
Figure 4.5:
12"
MIN,
1
[505rnm]
JACKET PANELS_
FAN
FAN ADAPTER GASKET
I/4-20 NUTS
& WASHERS
2"[51mm] MIN.
CLEARANCE
FLOOR
SLOPE UP 1/4"
PER FOOT
[20ram PER METER]_
HORIZONTAL /
FAN DRAIN TEE-/ /
ADAPTER _ /
L___l
l-VENT
ADAPTER
(SEE VENT PIPE
ADAPTER LISTING)
SILICONE
Direct Exhaust Vertical Venting
S TTACH VENT
MANUFACTURERS
LISTED RAIN CAP
._ASHING
"_ 3" DIA.
VENT PIPE
i I\ RRESTOP
SILICONE HOSE
DRAIN TRAP
(FORM 3"[76mm] DIA. LOOP)
At the time of removal of an existing boiler, follow these
steps 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 horizontal pitch and determine there is no
blockage or restriction, leakage, corrosion and other
deficiencies which could cause an unsafe condition.
C. 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 any clothes dryers and any
appliance not connected to common venting system.
Turn on any exhaust fans, such as range hoods and
bathroom exhausts, so they will operate at maximum
speed. Do not operate a summer exhaust fan. Close
fireplace dampers.
d. Place in operation the appliance being inspected.
Follow the lighting instrudions. Adjust thermostat so
appliance will operate continuously.
e. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame
of a match or candle, or smoke from a cigarette,
cigar, or pipe.
f. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers and
any other gas-burning appliance to their previous
conditions of use.
g. Any improper operation of the common venting
system should be corrected so that the installation
conforms with the National Fuel Gas Code, ANSI
Z223.1/N FPA 54 and/or CAN/CSA B149.1, Natural
Gas and Propane Installation Code. When resizing
any portion of the common venting system, the
common venting system should be resized to
approach the minimum size as determined using the
appropriate tables in the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and/or CAN/CSA B149.1,
Natural Gas and Propane Installation Code.
16

INSTALLATION AND OPERATING INSTRUCTIONS
1,
2,
3,
4,
5,
6,
Size and install the gas supply piping properly in
order to provide a supply of gas sufficient to meet
the maximum demand without undue loss of
pressure between the meter and the boiler.
Determine the volume of gas to be provided to the
boiler in cubic feet per hour. To obtain this value,
divide the Btu per hour rating (on the boiler rating
plate) by the heating value of the gas in Btu per
cubic feet. Obtain the heating value of the gas from
the gas supplier. As an alternative, use Table 5.1 or
5.2 on the next page to obtain the volume of gas to
be provided to the boiler.
Use the value obtained above as the basis for piping
sizing. Size the gas piping in accordance with Table
5.3. Consult the National Fuel Gas Code ANSI
Z223.1/NFPA 54 and or CAN/CSA B149.1, Natural
Gas and Propane Installation Code for proper sizing
options.
Locate the drop pipe adjacent to, but not in front of
the boiler.
Install a sediment trap. See Figure 5.1. Locate a tee
in the drop pipe at same elevation as the gas inlet
connection to the boiler. Extend the drop pipe to a
pipe cap.
Install a groundjoint union ahead of the gas control
assembly to permit servicing of the control. Some
local codes require an additional service valve when
using the combination gas controls. If your code
requires such a valve, a suggested location is shown
in Figure 5.1.
Use a pipe joint sealing compound that is resistant to
the action of liquefied petroleum gas. A non-resistant
compound may lose sealing ability in the presence of
this gas, resulting in a gas leak and fire or explosion
potential.
7, Check piping for leaks.
Use an approved gas detector, a non-corrosive leak
detection fluid or other leak detection method. If
leaks are found, turn off all gas flow and repair as
necessary.
Figure 5.1: Gas Connection to Boiler
8, Disconnect the boiler and its individual shut-off valve
from the gas supply piping system during any
pressure testing of that system at test pressure in
excess of 1/2 psig (3.5 kPa).
Do not subject the gas valve to more than 1/2 psi
(3.5 kPa) pressure. Doing so may damage the valve.
9,
Isolate the boiler from the gas supply piping system
by closing its individual service valve during any
pressure testing of the gas supply piping system at
test pressure equal to or less than 1/2 psig (3.5 kPa).
Minimum permissible supply pressure for purposes of
input adjustment:
Natural Gas 5.0" W.C. (1.2 kPa)
LP Gas 11.0" W.C. (2.7 kPa)
Maximum permissible supply pressure to the boiler
(Inches Water Column):
Natural Gas 13.5" W.C. (3.4 kPa)
LP Gas 13.5" W.C. (3.4 kPa)
When checking for leaks, do not use matches,
candles, open flames or other methods that provide a
source of ignition. This can ignite a gas leak,
resulting in fire or explosion.
17

INSTALLATION AND OPERATING INSTRUCTIONS
Table 5.1 : Natural Gas
Boiler
Size
7O
105
140
165
Input
(Cubic Ft/Hr)
7O
105
140
165
Input
(Cubic Meter/Hr)
2.0
3.0
4.0
4.7
Based on 1000 Btu/Cubic Ft.
Table 5.2: LP Gas
Boiler Input
Size (Cubic Ft/Hr)
7O
105
140
165
28
42
56
66
Input
(Cubic Meter/Hr)
0.8
1.2
1.6
1.9
Based on 2500 Btu/Cubic Ft.
Table 5.3: Pipe Capacity
Capacity of pipe of different diameters and lengths in cubic feet per hour
[cubic meter per hour] with a pressure drop of 0.3 inches of water [75 kPa]
and a specific gravity of 0.60. No allowance for an ordinary number of
fittings is required.
Pipe
Length in
Feet
[Meters]
lO [3.o]
20 [6.1]
30 [9,1]
40 [12.2]
50 [15.2]
60 [18.3]
/4 M
Pipe
278 [7.9]
190 [5.4]
152 [4.3]
130[3.7]
115[3.3]
105[3.0]
1M
Pipe
520 [1 4.7]
350 [9.9]
285 [8.1]
245 [6.9]
215 [6.1]
195[5.5]
11/4"
Pipe
1050 [29.7]
730 [20.7]
590 [16.7]
500 [14.2]
440 [12,5]
400 [11.3]
11/2"
Pipe
1600 [45.3]
11oo[31.1]
890 [25.2]
760 [21.5]
670 [19.0]
610 [17.3]
Maximum Capacity Correction Factors for
Specific Gravity other than 0.60.
Specific Gravity 0.50 0.55 0.60 0.65 0.70 0.75
Correction Factor 1.10 1.04 1.00 0.96 0.93 0.90
Specific Gravity 0.80 0.85 0.90 1.00 1.10 1.20
Correction Factor 0.87 0.84 0.82 0.78 0.74 0.71
Specific Gravity 1.30 '1.40 '1.50 1.60 1.70 1.80
Correction Factor 0.68 0.66 0.63 0.61 0.59 0.58
18

INSTALLATION AND OPERATING INSTRUCTIONS
Install all electrical wiring in accordance with the National Electrical Code and local requirements.
This unit when installed must be electrically grounded in accordance with the requirements of the authority
having jurisdiction or, in the absence of such requirements, with the current edition of the National Electrical
Code, ANSI/NFPA 70 and/or the Canadian Electrical Code, Part 1, CSA C22.1, Electrical Code.
V.'I Lr_rlI_ h_[_
1. See Figure 6.1 for location of wiring and controls. 1.
Use Figure 6.2 to connect the boiler to a power
supply and to connect components to the boiler.
2. Connect the boiler by a separate, permanently live
electrical supply line with a fused switch.
3. Adjust the thermostat heat anticipator to 0.2 Amp.
See Figure 6.4 for typical wiring with zone valves. See
Figure 6.5 for typical wiring with zone circulators. When
wiring a zoned heating system, follow all applicable
codes, ordinances and regulations.
2.
3.
4.
For proper location of controls and accessories refer
to Figure 6.1 and Section 11.
See the attached control sheets for specific details
regarding the installation of the various controls.
This boiler is supplied with safety devices in addition
to the limit. For a description of these devices and
how they work to ensure the safe operation of the
boiler, see Section 7B.
If the circulator is mounted in the supply piping,
provide longer wiring harness as required.
Do not power zone valves directly from the boiler
transformer/relay. Doing so will greatly reduce the life
of the transformer. Use a separate transformer sized
to handle the total of all zone valve electrical loads.
TO
TO CIRCULATOR LINE VOLTAGE
POWER SUPPLY
LIMIT
FAN
FAN/RELAY CENTER
VALVE INNER
JACKET
PANEL
Figure 6.1 :
FLAME ROLLOUT
SWlTCH
PRESSURE
SWITCH
Wiring, Controls and Safety Devices
19

INSTALLATION AND OPERATING INSTRUCTIONS
THESE ITEMS TO BE
SUPPLIED BY iNSTALLER
11516011 LI ]=_
PokER_--_-4_
SUPPLY _-L _! !
I,__SERVlCE IW I
JUNCTION BOX _ B
l
BK
BL
HIGH LIMIT
CON_OL J
CIRCU_TOR j_BK i
GROUND S_EW
(UNDER_DE OF J
PLATE)
BK
120V F
ISOLA_ON/1
RELAY "4" L_
--_###yRt'#_S _P_A=MOUN_D
/_ANSFORMER/RELAY
I_F_ %®Iiii I
Yi L Ti-r
_ _r-- PRESSUREI " [? !
I '_l s_TCH ' I r--_-_--_---i
BL _ _[--_L,oiL=---- I
_AME _R --
ROLLOUT
SWITCH
THERMOSTAT
24V
(BY OTHERS)
_NNECTI_ DIAGRAM LE_ND _RE CODE
LINE VOLTA_ SIZE 14 AWG _E _, _N OR TEW/A_ _RE R RED
-- LINE VOLTA_ SIZE 16-18 AWG _E _, _ OR _W/A_ _RE BK BLACK
WWHrTE
-- -- -- LOW VOLTAGE SIZE 16-18 AWD WIRE TYPE TW, TEW/AWM, TFFN WIRE 0 ORANGE
.... HONEYWELL PILOT WIRE BL BLUE
BR BROWN
NOTES: PR PURPLE
1) ALL WIRING MUST COMPLY WITH APPLIANCE CODES, ORDINANCES AND REGULATIONS.
2) IF ANY OF THE _IGINAL WIRE AS SUPPLIED WITH THE APPLIAN_ MUST BE
R_LACED, IT MUST BE REPLACED WI_ WIRE AS SHOWN.
u(HOT) L2
RELAY
COIL
CIRCULATOR
BK PRIMARY W
3RANSFORMER
F- 7
I I "---N-t _-7 I
II
L/R _ RELA_
--f_Lcly_ _"ERMO6_A__._ i
NiR-1 I
_-- _ME PR LBR
ROLL_T _ 3
SWITCH 0 -> 1>- GAS j
V,_Lvr- l
LADDER DIAGRAM LEGEND ELEMENT SENSOR _L-GROUND
(PILOT
-- 120V WIRING _BING)
i -- -- 24V WIRING
Figure 6.2: Wiring and Connection Diagram
1. Thermostat calls for heat, energizes Control Relay
(CR).
2. Control Relay (CR) energizes circulator.
3. Limit senses boiler water temperature. Prevents
boiler operation until water temperature falls
approximately 15°F (8°C) below the cut-out
temperature.
4. Limit energizes Fan and Isolation Relay (IR).
5. Negative pressure induced by fan switches Pressure
Switch, continuing power through closed contacts
(IR-1) and flame roll-out switch.
6. Gas valve energizes.
a. Igniter on.
b. Pilot gas on, igniting pilot.
7. Pilot flame detected.
a. Igniter off.
b. Main gas on, igniting main burners.
Note: If pilot flame is not detected within 30 seconds,
the igniter is turned off for 30 seconds, and then turned
back on. If the pilot is not detected within 30 seconds,
the igniter and pilot gas are turned off for 5 minutes.
The sequence then resumes at Step 6a.
8. Call for heat ends.
a. Pilot and main gas off, extinguishing pilot and
main burners.
b. Fan and circulator off.
20