HydroTherm HC-65 Owner's manual

HCD2-501
42-9156 REV. 1
AA
AA
AA
HYDROTHERM
IN UNITED STATES: 260 NORTH ELM ST., WESTFIELD, MA 01085 [phone]/FAX [phone]
IN CANADA: 5211 CREEKBANK ROAD, MISSISSAUGA, ONT. L4W 1R3 [phone]/FAX [phone]
MODEL HC-D SERIES
INSTALLATION,
OPERATION &
MAINTENANCE
MANUAL & REPLACE-
MENT PARTS MANUAL
Gas-Fired Cast Iron Water Boilers
65,000 to 165,000 Btuh Input
Intermittent Pilot & Vent Damper
SECTION 1: BOILER INSTALLATION
Introduction...............................................................2
Step 1: Locating & Setting the Boiler........................3
Step 2: Installing/Purging Water Piping.....................4
Step 3: Venting the Boiler..........................................6
Step 4: Installing/Testing Gas Piping ........................8
Step 5: Wiring the Boiler...........................................9
SECTION 2: START-UP & OPERATION
Safety Controls........................................................15
Start-Up & Adjustments...........................................15
SECTION 3: MAINTENANCE
Water Treatment......................................................18
Freeze Protection ....................................................18
Before Each Heating Season..................................18
How To Change Orifices..........................................19
Troubleshooting.......................................................19
Appendix A (French Vent Damper Translation)....... 20
Replacement Parts List......................................... 21
MEA# 90-77-E

2
ANSI/ASME CODE COMPLIANCE: Installation must
conform to requirements of authority having jurisdiction
or, in absence of such requirements, to National Fuel
Gas Code ANSI Z223.1-latest edition and to National
Electric Code NFPA-70-latest edition. Where required by
authority having jurisdiction, installation must also con-
form to Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD-1-latest
edition.
For Canada, the installation must be in accordance with
Standards CAN/CGA-B149.1 or .2 Installation Codes for
Gas Burning Appliances and Equipment and with Stan-
dard C.S.A. C22.1 Canadian Electrical Code, Part 1 and
Part 2, and/or local codes.
BOILER SHIPMENT: Each boiler is shipped in a single
carton. There is a vent damper packed separately with
the boiler.
MODEL HC-D BOILER DIMENSIONS
1 1/4"
RETURN
A
DIMENSIONS
BOILER
MODEL
HC-65
HC-85
HC-100
HC-120
HC-145
HC-165
A
19 1/2"
23 3/4"
27 1/4"
29"
23 3/4"
23 3/4"
B
12 3/4"
16"
12 3/4"
12 3/4"
12 3/4"
12 3/4"
C
16 1/2"
30 1/2"
33- /4"
32 1/2"
16 1/2"
16 1/2"
D
39 5/8"
43 7/8"
57 7/8"
64 1/8"
65 1/8"
43 7/8"
E
5"
5"
5"
6"
6"
7"
PRESS./RELIEF VALVE
HC-85, 100, 120
GAS VALVE
1 1/2" SUPPLY
HC-65, 145, 165
5 1/2"
1 1/2" SUPPLY
HC-85, 100,120
CIRCULATOR
(PACKAGED
BOILERS)
AIR ELIMINATOR
TAPPING
EXPANSION TANK
TAPPING
DRAIN
VALVE
HI-LIMIT AQUASTAT
TEMP./PRESS. INDICATOR
PRESS./RELIEF VALVE
HC-65, 145, 165
3 5/8"
VENT DAMPER
SPILL
SWITCH
ROLLOUT SWITCH
E
C
D
A
B21 3/4" 7 3/4"
DANGER: Indicates an imminently hazardous sit-
uation which, if not avoided, will result in death,
serious injury or substantial property damage.
WARNING: Indicates a imminently hazardous sit-
uation which, if not avoided, could result in
death, serious injury or substantial property dam-
age.
CAUTION: Indicates a imminently hazardous situa-
tion which, if not avoided, may result in minor
injury or property damage.
NOTE: Used to notify of special instructions on
installation, operation or maintenance which are
important to equipment but not related to personal
injury hazards.
The following terms are used throughout this manual to bring attention to the presence of potential hazards
or to important information concerning the product:
WARNING: Installers must follow local regulations
with respect to the installation of CO detectors and
follow the manufacturer's stated maintenance
schedule for this boiler!
ATTENTION: Observer les règlements règional à
l'egard des détecteurs de monoxyde de carbone et
observer entretien de manufacturier pour cette
chaudière!

3
SECTION 1: BOILER INSTALLATION
STEP 1: LOCATING & SETTING THE BOILER
PROCEDURE A: Check that provisions for combustion air are in accordance with National Fuel Gas Code
ANSI Z223.1-latest edition and all applicable local codes.
In Canada, follow CAN/CGA B149.1 or .2 installation codes.
If boiler is installed in an unconfined space,adequate air
will be available via normal infiltration.
If boiler is installed in a confined space (a space with a
volume of less than 50 cubic feet per 1000 Btu/hr of gas
input for all fuel burning equipment) or building construc-
tion is unusually tight, adequate air for combustion must
be provided by two openings: one located about 6" below
the ceiling, the other about 6" above the floor. When
communicating directly with the outside, each opening
must have a minimum free area of one square inch per
4000 Btu/hr of gas input. When ventilation air is provided
by openings in doors, etc. to adjoining spaces having
adequate infiltration, each opening must have a minimum
free area of one square inch per 1000 Btu/hr of gas
input.
NOTE: Boiler employs atmospheric combustion.
Combustion air must not be contaminated with halo-
genated hydrocarbon vapors, aerosol propellants or
freon; otherwise, heat exchanger will be subject to
corrosion, reducing boiler life.
FRONT
CLOSET
(6")
TOP
48"
AAAAA
SIDE
VIEW
REAR
(6")
W/O CIRC.
24" WITH
CIRCULATOR
(RECOMMENDED
FOR SERVICING)
6"
LEFT 6"
RIGHT
VENT
DAMPER
FRONT
VIEW RECOMMEND
MORE FOR
ACCESS TO
VENT DAMPER
POSITION
INDICATOR
6"
6" FIGURE 1.1
PROCEDURE B: Check mini-
mum clearances to com-
bustibles are proper as
shown. Local requirements
may specify greater clear-
ances & must be adhered to.
Boiler shall be installed such
that the gas ignition system
components are protected
from water (dripping, spray-
ing, rain, etc.) during appli-
ance operation and service
(circulator replacement, con-
densate trap, control replace-
ment, etc.).
NOTE: Do not loosen tie rods on absorption unit. They accommodate thermal expansion. Loss of boiler
structural integrity and water leaks/damage may result.
CAUTION: Locate boiler so horizontal connecting flue pipe is as short as possible. Maximize height of verti-
cal flue connector.
WARNING: Never install boiler on combustible flooring without combustible flooring pan or on carpeting as
heat damage and/or fire may result.
WARNING: This boiler must be supplied with com-
bustion air in accordance with Section 5.3, Air for
Combustion & Ventilation, of the latest revision of
the National Fuel Gas Code, ANSI Z223.1 and all
applicable local building codes. Failure to provide
adequate combustion air for this appliance can result
in severe personal injury or death!
PROCEDURE C: Check component positioning.
1. Remove all packing material from boiler.
2. Check that burners and controls are in the proper
position.
3. Check proper seating of baffle grid inside of dome
opening (see Figure 1.2).
BAFFLE GRID
DOME
TOP VIEW FIGURE 1.2

4
STEP 2: INSTALLING & PURGING WATER PIPING
PROCEDURE B: Install supply and return water pip-
ing. For Models HC-65, 145 & 165, supply outlet is
at rear of boiler and vent fitting assembly tapping is
at front of boiler.
If boiler is installed above level of radiation, a low
water cut-off must be used.
ALL EXTERNAL PIPING MUST BE SUPPORTED BY
HANGERS, NOT BY BOILER OR ACCESSORIES.
PRESS. REDUCING
(FILL) VALVE
DRAIN VALVE
SHUT-OFF
VALVE
SHUT-OFF VALVE
SHUT-OFF
VALVE
SHUT-OFF
VALVES
CIRCULATOR
FIGURE 1.4
NOTE: Boiler must not be used without forced circulation, as overheating or failure of cast iron sections may
result.
PROCEDURE A: Install vent tapping assembly, components and relief valve discharge piping. For Models
HC-65, 145 & 165, supply outlet is at rear of boiler and vent fitting assembly tapping is at front of boiler.
Relief Valve Discharge Piping: Must terminate 6"
above floor & be same size or larger than valve out-
let.
CAUTION: Piping must be installed from relief valve
discharge so there will be no danger of scalding per-
sonnel.
PRESS. RELIEF
VALVE
RELIEF VALVE
DISCHARGE
PIPING
VENT
FITTING
ASS'Y.
AIR VENT
MAY BE PIPED TO
EITHER SIDE OF BOILER
VERTICAL EXPANSION TANK
ARRANGEMENT (PREFERRED)
1/2" NPT TAPPING HORIZONTAL EXPANSION
TANK ARRANGEMENT
MAY BE SCREWED
INTO TAPPING
FIGURE 1.3
WARNING: No valve of any type may be installed
between boiler & relief valve to prevent accidental
explosion from over-pressure.

5
CAUTION: To prevent damage due to excessive con-
densation, one of the following piping options
should be used.
SYSTEM BYPASS
For systems using a circulator on the return as either a sin-
gle zone, or multiple zones with zone valves, install a sys-
tem bypass line between the supply and return on the suc-
tion side of the circulator (see Figure 1.5). Install a metering
valve in this bypass line to regulate the amount of flow that
will be diverted to the return. A plug valve offers the best
control for this application. Although other valves may be
less expensive, a plug valve will be easier to set accurately.
In the absence of a flow indicator, set the metering valve
using temperature as a guide. The accompanying dia-
gram suggests one scenario. This addition requires only
two tees, a plug valve, and a small amount of pipe and
offers the simplest approach to reliably control condensa-
tion. For this system and those that follow, be aware that
you are using a percentage of the pump capacity to
blend, but the friction loss for the entire pump flow has
been reduced. In most cases, the standard pump pack-
aged with the boiler has enough capacity to feed the
baseboard distribution system and the bypass line.
PUMP AWAY BYPASS
For systems that use a single circulator to pump away
from the boiler, the bypass should be installed on the dis-
charge side of the circulator (see Figure 1.6). Full tem-
perature water supplies the baseboard distribution sys-
tem as before. Half of the circulator’s volume moves
through the bypass, blending and heating the cooler
return water. Again, the cost of installing the bypass is
small and setting it by temperature can be accomplished
with a contact thermometer.
PUMPED BLEND
An additional circulator can also be used to provide a
return water temperature blend. This method works well
with systems with multiple zones with circulators (see
Figure 1.7). The dedicated bypass circulator provides a
strong blending flow without diminishing the flow avail-
able to any heating zone. Any residentially sized circula-
tor is adequate for this purpose.
Each of these bypass solutions also has the added ben-
efit of increasing circulation in the boiler which will maxi-
mize tankless coil output and increase the accuracy of
temperature sensing controls.
REVERSE ACTING AQUASTATS
An alternative for existing systems experiencing condensa-
tion that does not require re-piping the boiler utilizes a
reverse acting aquastat, one that makes on temperature
rise. This approach works best in single zone systems.
Wired in series with the circulator, this control holds the cir-
culator off until the boiler reaches an acceptable tempera-
ture and then starts system circulation (see Figure 1.8).
SUPPLY RETURN
50%
120°F
100%
140°F
100%
160°F
50%
160°F
50%
160°F
SYSTEM
BYPASS FIGURE 1.5
SUPPLY RETURN
50%
120°F
100%
140°F
100%
160°F
50%
160°F
50%
160°F
PUMP AWAY
BYPASS
FIGURE 1.6
SUPPLY RETURN
100%
120°F
200%
140°F
200%
160°F
100%
160°F
100%
160°F
PUMPED
BYPASS
FIGURE 1.7

6
PROCEDURE D: Completely fill & purge
heating system. Make sure that all heat-
ing system manual air vents are closed.
1. Check flow direction arrows on hydronic
components are facing in proper direction.
2. Attach hose to drain valve "B" and close
valve "A". Open valves "C", "D", "E" and "F"
and drain valve "B". Fill system with water
until water runs out of the hose in a steady
stream (no visible air bubbles).
3. Close valves "C" and "D". Open valve "A".
When water runs out of the hose in a steady
stream (no visible air bubbles), close drain
valve "B".
4. Open valves "C" and "D".
VALVE “B”
VALVE “C”
VALVE “A”
VALVE “D”
VALVE “E”
VALVE “F”FIGURE 1.10
FOR WATER TREATMENT & FREEZE PROTECTION REQUIREMENTS,
SEE "SECTION 3: MAINTENANCE" IN THIS MANUAL
If a hot water boiler is installed in connection with a water
chiller, the chilled water must be piped in parallel with the
boiler, using appropriate valves to prevent the chilled
medium from entering the boiler (see Figure 1.9). When
boilers are connected to heating coils located in air han-
dling units where they may be exposed to refrigerated air
circulation, such boiler piping system shall be equipped
with flow-control valves or other automatic means to pre-
vent gravity circulation of the boiler water during the cool-
ing cycle.
PROCEDURE C: For combination heating and cooling installations only.
NOTE: VALVES "H" OPENED ON HEATING WITH "C" VALVES
CLOSED REVERSE PROCEDURE ON COOLING.
EXP. TANK VENT ROOM
UNIT
DRAIN CHILLER
BOILER
H
C
PUMP
RELIEF
VALVE
FILL
VALVE
DRAIN
C
H
BOILER FIGURE 1.9
The most commonly available reverse acting aquastat is
a Honeywell L4006B. The aquastat should be mounted
in an immersion well directly installed in the boiler. The
use of heat conductive grease (Honeywell part #
972545) in the immersion well is strongly recommended
for fast and accurate temperature response. Set this
adjustable aquastat to make at no less than 130°F.
While this method can cause the circulator to cycle more
frequently, setting the aquastat’s differential to the maxi-
mum (25-30°F) will minimize short cycling.
reverse
aquastat
N.O.
T
Tt'stat
GV
115 volts
24 volts
circulator
operating
aquastat
N.C.
REVERSE
AQUASTAT
SET AT 120° F FIGURE 1.8

7
STEP 3: VENTING THE BOILER
NOTES: Additional venting and chimney requirements are provided on page 8.
For boilers equipped with intermittent pilot install plug supplied in damper
package into damper vane hole. For standing pilot boilers discard plug.
PROCEDURE B: Install vent damper. (For French version, see Appendix A at rear of manual.)
FLOW DIRECTION
ARROW POINTS UP
MOUNT
VENT DAMPER
OVER
DRAFTHOOD
MAKE SURE
MOTOR IS
LOCATED
ON LEFT SIDE
1. Mount damper on top of draft hood.
FIGURE 1.12
ATTACH LOWER
PORTION OF
VENT DAMPER
TO DRAFTHOOD
WITH 1/2" OR
SHORTER SCREWS
OR POP RIVETS
2. Secure damper to draft hood.
FIGURE 1.13
PLUG INTO MOLEX
RECEPTACLE ON FRONT
OF BOILER
PLUG INTO MOLEX
RECEPTACLE INSIDE
DAMPER MOTOR VENT
DAMPER
WIRE
HARNESS
3. Connect wire harness.
FIGURE 1.14
PROCEDURE A: Mount draft hood and spill switch
on boiler.
1. Install draft hood on boiler. If draft hood shroud has a
hole near the relief opening, mount draft hood so hole
faces to the front of the boiler.
2. HC-D boilers are equipped with factory-mounted spill
switch harness/mounting bracket assembly; spill switch is
provided in bag on boiler front.
3. Install mounting bracket on outside surface of draft
hood shroud with the screws provided (HARNESS
MUST BE ON OUTSIDE OF SHROUD). Install spill
switch in hole in shroud (on outside surface) with the
screws provided.
INSTALL
SWITCH
IN OPENING
ON DRAFTHOOD
CONNECT
WIRE
LEADS
INSTALL
MOUNTING
BRACKET
ON DRAFTHOOD
FIGURE 1.11
4. Plug wiring leads from harness/bracket assembly onto
flat terminals on spill switch.
NOTE: Boiler will not operate unless wiring leads to
spill switch are connected.
DANGER: Only the boiler may be served by the vent damper. Do not use it to vent an additional appliance;
this will cause fire or carbon monoxide poisoning.
DANGER: Draft hood and vent outlet must not be altered, as proper operation would be jeopardized;
flame rollout, fire or carbon monoxide poisoning will result.

8
ADDITIONAL VENTING REQUIREMENTS: When con-
necting to gas vents or chimneys, vent installations shall
be in accordance with Part 7, Venting of Equipment, of
the National Fuel Gas Code, ANSI Z223.1-latest edition,
or applicable provisions of the local building codes.
Vent connectors serving appliances vented by natural
draft shall not be connected into any portion of mechani-
cal draft systems operating under positive pressure.
When two or more appliances vent into a common flue,
the area of the common flue should be at least equal to
the area of the largest flue plus 50% of the areas of the
additional flue or vent connectors.
When an existing boiler is removed from a common vent-
ing system, common venting system is likely to be too
large for proper venting of appliances remaining connect-
ed to it. At time of removal of existing boiler, following
steps shall be followed with each appliance remaining
connected to the common venting system placed in oper-
ation, while other appliances remaining connected to
common venting system are not in operation:
1. Seal all unused openings in common venting system.
2. 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.
3. Insofar as is practical, close all building doors and win-
dows and all doors between the space in which the appli-
ances remaining connected to the common venting sys-
tem 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 maximum speed. Do not operate a summer
exhaust fan. Close fireplace dampers.
4. Place in operation the appliance being in-spected. Fol-
low the lighting instructions. Adjust thermostat so appli-
ance will operate continuously.
5. Test for spillage at draft hood relief opening after 5
minutes of main burner operation. Use the flame of a
match or candle, or smoke from cigarette, cigar or pipe.
6. After it has been determined that each ap-pliance
remaining connected to common venting system properly
vents when tested as outlined above, return doors, win-
dows, exhaust fans, fireplace dampers and any other
gas-burning appliance to previous conditions of use.
7. Any improper operation of the common venting system
should be corrected so installation conforms with the
National Fuel Gas Code, ANSI Z223.1-latest edition.
When resizing any portion of the common venting sys-
tem, the common venting system should be resized to
approach the minimum size as determined using the
appropriate tables in Appendix G in the National Fuel
Gas Code, ANSI Z223.1-latest edition. For Canada, the
provisions of CAN/CGA B149.1 or .2 shall apply.
ADDITIONAL CHIMNEY REQUIREMENTS: Chimney
condition is of paramount importance for a safe and effi-
cient boiler installation. All installations must include a
chimney inspection by a qualified individual or agency.
Chimney construction materials must be compatible with
the fuel being used.
Particular attention should be paid on all oil-to-gas con-
versions.Soot may have accumulated in chimney and/or
degraded chimney liner. Most utilities require complete
chimney cleaning. Others may require installation of new
liner, spill switches or other chimney upgrades. Check
with local utility for required safety precautions.
AAAAA
MAXIMUM
6-FT
APART
PITCH 1/4"
PER FOOT
SECURE
FLUE PIPE
TO VENT
DAMPER
USE VENT SUPPORT(S) AS REQUIRED TO PREVENT SAGGING
INSTALL
FLUSH
WITH
INSIDE
CHIMNEY
LINER
SEAL
WITH
FURNACE
CEMENT
SINGLE WALL
OR TYPE B
FLUE PIPE
HC-65 = 5"
HC-85 = 5"
HC-100 = 5"
HC-120 = 6"
HC-145 = 6"
HC-165 = 7"
PROCEDURE C: Install flue pipe between vent
damper and chimney (6" minimum clearance
required between flue pipe and combustibles).
FIGURE 1.15
DANGER: A chimney which does not meet modern
safety standards will result in a fire or deadly carbon
monoxide poisoning of the building residents.

9
STEP 4: INSTALLING & TESTING GAS PIPING
Maximum Capacity of Pipe in Cubic Feet of Natural Gas per Hour for Gas Pressures of
0.5 Psig or Less and a Pressure Drop of 0.3 Inch Water Column
(Based on a 0.60 Specific Gravity Gas)
Nominal
Iron Pipe
Size,
Inches
Internal
Diameter
Inches
Length of Pipe, Feet
10
32
72
132
278
520
1,050
1,600
3,050
4,800
8,500
17,500
20
22
49
92
190
350
730
1,100
2,100
3,300
5,900
12,000
30
18
40
73
152
285
590
890
1,650
2,700
4,700
9,700
40
15
34
63
130
245
500
760
1,450
2,300
4,100
8,300
50
14
30
56
115
215
440
670
1,270
2,000
3,600
7,400
60
12
27
50
105
195
400
600
1,150
1,850
3,250
6,800
70
11
25
46
96
180
370
560
1,500
1,700
3,000
6,200
80
11
23
43
90
170
350
530
990
1,600
2,800
5,800
90
10
22
40
84
160
320
490
930
1,500
2,600
5,400
100
9
21
38
79
150
305
460
870
1,400
2,500
5,100
125
8
18
34
72
130
275
410
780
1,250
2,200
4,500
150
8
17
31
64
120
250
380
710
1,130
2,000
4,100
175
7
15
28
59
110
225
350
650
1,050
1,850
3,800
200
6
14
26
55
100
210
320
610
980
1,700
3,500
1/4"
3/8"
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
2-1/2"
3"
4"
.326
.493
.622
.824
1.049
1.380
1.610
2.067
2.469
3.026
4.026
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquifi
Petroleum Gases (at 11 Inches Water Colum Inlet Pressure)
(Based on aPressure Drop of 0.5 Inch Water Column)
Nominal
Iron Pipe
Size,
Inches
Length of Pipe, Feet
10
275
567
1071
2205
3307
6221
20
189
393
732
1496
2299
4331
30
152
315
590
1212
1858
3465
40
129
267
504
1039
1559
2992
50
114
237
448
937
1417
2646
60
103
217
409
834
1275
2394
70
96
196
378
771
1180
2205
80
89
185
346
724
1086
2047
90
83
173
322
677
1023
1921
100
78
162
307
630
967
1811
125
69
146
275
567
866
1606
150
63
132
252
511
787
1498
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
FIGURE 1.16
PROCEDURE A: Select gas pipe size which will result in a pressure drop of less than 0.3" W.C. for natural
gas or 0.5" W.C. for propane, following example below.
Example: Boiler Model HC-120D is to be installed. Distance from existing gas meter to installation site is 20 ft.
What pipe size must be used? Local utility indicates heating value of natural gas being supplied is 1020 Btu per
cu.ft. Determine cubic feet of gas per hour for above boiler model:
120,000 Btu per hour = 117.6 cu.ft. per hour
1020 Btu per cu.ft.
1. Find 20 ft. in upper portion of the table for natural gas under "Length of Pipe, Feet" heading.
2. Moving down the column, match required capacity. Higher capacity acceptable. In our case it is 190 cu.ft.
3. Move to left-hand column "Nominal Iron Pipe Size, Inches"; read required pipe size. In our case it is 3/4".
10 20 30 40 50 60 70 80 90 100 125 150 175 200
10 20 30 40 50 60 70 80 90 100 125 150
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquefied
Petroleum gases (at 11 Inches of Water Column Inlet Pressure)
(Based of a Pressure Drop of 0.5 Inch Water Column)

10
DANGER: Before placing gas piping into service, carefully test it to assure every joint is gas tight. Bubble
test all joints with a soap solution. NEVER TEST WITH AN OPEN FLAME AS FIRE OR EXPLOSION MAY
RESULT.
For any pressure testing in excess of 1/2 psi, the boiler
and its individual shutoff valve must be isolated from the
piping system by disconnecting them and capping the
outlet(s). For any pressure testing equal to or less than
1/2 psi, the boiler must be isolated from the piping sys-
tem by closing its manual shutoff valve.
Minimum pressure required at the gas valve inlet is 5"
W.C. for natural gas and 11" W.C. for propane. Maxi-
mum pressure allowable at the gas valve inlet is 12" W.C.
If the gas pressure is above this limit, a pressure regula-
tor must be installed. If the gas pressure is below these
limits, contact the local utility.
PROCEDURE C: Test gas piping.
WHEN TESTING IS COMPLETED, CLOSE MAIN GAS SHUT-OFF VALVE
& SET BOILER COMBINATION GAS VALVE IN "OFF" POSITION.
PROCEDURE B: Connect gas piping from meter to
boiler following good piping practices. Pipe joint
compound must be compatible with the fuel (NG or
LP) being used. Check local codes and utilities for
any requirements.
All piping must be supported by hangers, not by
boiler or accessories.
AAAAAAAAA
RISER TO OTHER
APPLIANCES
BEAM
PIPE CLAMP GAS
METER
GAS
VALVE
UNION
SEDIMENT
TRAP
MANUAL MAIN
SHUT OFF
VALVE
FIGURE 1.17
STEP 5: WIRING THE BOILER
All electrical wiring must be in accordance with require-
ments of authority having jurisdiction or, in absence of
such requirements, to National Electric Code NFPA-70-
latest edition. If external source is utilized, boiler must be
electrically grounded in accordance with the require-
ments of authority having jurisdiction or, in absence of
such requirements, with National Electric Code NFPA-
70-latest edition. UL listed power limited circuit cable is
almost universally approved for safety controls on heat-
ing equipment, either internally or externally, without pro-
tection of conduits or raceway.
For Canada, all electrical connections are to be made in
accordance with Standard C.S.A. C22.1 Canadian Elec-
trical Code, Part 1 and Part 2 and/or local codes.
NOTE: If any original wire supplied with the boiler
must be replaced, use similar wire of 105 C rating.
Otherwise, insulation may melt or degrade, exposing
bare wire.
NOTE: Boiler transformer must not be used to power
external accessories (i.e., zone valves, relays, etc.).
Otherwise, boiler transformer will be overloaded and
will burn out.
A separate 115V (60Hz) power supply is recommended
for the boiler. Use standard 15-amp fuse and 14-gauge
wire from power supply to boiler. Follow the wiring dia-
gram for your particular installation as shown in Figures
1.18 through 1.24.
WARNING: Turn off electric power supply before ser-
vicing. Contact with live electric components can
cause shock or death.

11
FIGURE 1.18: WIRING DIAGRAM & OPERATION
SEQUENCE FOR BOILERS WITH IID &
VENT DAMPER
FIGURE 1.19: WIRING DIAGRAM & OPERATION
SEQUENCE FOR BOILERS WITH IID,
VENT DAMPER & L8148E AQUASTAT RELAY

12
FIGURE 1.20: WIRING DIAGRAM & OPERATION
SEQUENCE FOR BOILERS WITH IID, VENT DAMPER
& DUAL AQUASTAT L4081A
FIGURE 1.21: WIRING DIAGRAM & OPERATION
SEQUENCE FOR BOILERS WITH IID, VENT DAMPER,
R8285 CONTROL CENTER & DUAL AQUASTAT L4081A

13
FIGURE 1.22: WIRING DIAGRAM &
OPERATION SEQUENCE FOR BOILERS WITH IID,
VENT DAMPER, & DUAL AQUASTAT L4081B

14
R1: AQUASTAT RELAY - L8148E
GV: GAS VALVE
ZV1: ZONE VALVE
ZV2: ZONE VALVE
ZV3: ZONE VALVE
T2: 24V TRANSF.
TH1: ZONE T'STAT
TH2: ZONE T'STAT
TH3:ZONE T'STAT
TH
TR GV
TH
TR
TH1
N
H115V
ZV1
ZV2
ZV3
YEL RED
YEL
YEL
YEL
YEL
YEL
RED
RED
RED
RED
RED
T2
R1
TV T
2
W
B1 B2
C1 C2
L1 L2 N
H115V
TO CIRC.
TH2
TH3
FIGURE 1.23: WIRING DIAGRAM FOR ZONING WITH ZONE VALVES
FIGURE 1.24: WIRING DIAGRAM FOR ZONING WITH CIRCULATORS
C2
C1
231 4
T
T
23
14
X
XTX
TX
TH1 TH2
ZR1 ZR2
N
H
115V
TH TR
GV
T1
TO
ADDITIONAL
ZONES
H1
C1: ZONE CIRCULATOR
TH1: ZONE T'STAT
C2: ZONE CIRCULATOR
TH2: ZONE T'STAT
ZR1: ZONE RELAY (RA832A
OR EQUIVALENT)
ZR2: ZONE RELAY (RA832A
OR EQUIVALENT)
H1: HI-LIMIT AQUASTAT
GV: GAS VALVE
T1: 24V TRANSFORMER
T2,T3: TRANSF. (IN RELAYS)
1R-1, 1R-2: ZR1 CONTACTS
2R-1, 2R-2: ZR2 CONTACTS
FACTORY WIRING
FIELD WIRING T1
115V 1R-2 2R-2
H1
BOILER CIRCUIT
1R-1
T2
2R-1
T3 TH2 TH1
ZR1 ZR2
CIRC.
1CIRC.
2
115V
BLACK
WHITE EXTERNAL CIRCUIT
GAS VALVE
COIL

15
SECTION 2: START-UP & OPERATION
Safety Controls
Spill switch (see Figure
2.1) detects the escape
of combustion products
through the draft hood
relief opening and inter-
rupts the power to the
gas valve preventing
unsafe boiler operation.
Escape of flue products
could be caused by a
blocked or collapsed
chimney or by inade-
quate chimney draft.
This is a manual re-
set-type device and
can be reactivated by
depressing the spill
switch reset button.
Flame rollout switch (see
Figure 2.1) prevents
flame rollout from the boiler combustion chamber,
caused by blocked boiler flue passageways, by interrupt-
ing power to the gas valve to prevent unsafe boiler oper-
ation. This is either a single use device, which must be
replaced if it is tripped, or a manual reset-type device
that can be reset by depressing the reset button. Flue
passages must be inspected by a qualified installer if
problem occurs, prior to switch being replaced or reset.
START-UP & ADJUSTMENTS
Safe lighting and other performance criteria were met
with the gas manifold and control assembly provided on
the boiler when the boiler underwent tests specified in
ANSI Z21.13-1991.
1. Bleed all heating system air vents, starting on lowest
floor. Open vents one at a time until water squirts out.
Close vent and repeat procedure with remaining vents.
FLAME
ROLLOUT
SWITCH
SPILL
SWITCH
FIGURE 2.1
2. Make sure boiler combination gas valve is in OFF
position. Then, open main gas shutoff valve, allowing gas
to flow to boiler.
3. Set thermostat heat anticipator at .8 amp when ther-
mostat is controlling boiler directly. When zone con-
trolled, set heat anticipator to amp draw of zone valve or
circulator pump relay.
4. Set thermostat to call for heat and turn on electrical
power to boiler. Observe that vent damper position indi-
cator has rotated to open position (see Figure 2.2).
Damper must be in
open position when
boiler main burner is
operating. In case of
a damper malfunc-
tion, the damper
blade may be manu-
ally placed in the full
open position to per-
mit burner operation.
To accomplish this,
first disconnect elec-
trical power and then
separate the vent
connector from the
damper. Manually (using hand tools if required) rotate
the blade until the end switch closes. Reposition and
reconnect the vent connector to the boiler before turn-
ing on the electrical power.
5. Allow circulator to run 15 to 30 minutes, which should
purge any leftover air from system. Check automatic air
vent for the proper operation and entire system for any
leaks. Make sure all air is purged from system before
lighting boiler.
6. Set thermostat to no longer call for heat. Observe that
damper position indicator rotated to closed position.
7. Set thermostat to lowest setting and light boiler follow-
ing lighting instructions in Figure 2.4. Boiler is equipped
with flame rollout switch to shut down boiler in case of
sustained flame roll-out or excessive heat behind front
panel. If switch opens, see the information on "Safety
Controls" on this page.
8. Observe pilot and main burner flame (see Figure 2.3).
All burner ports should be ignited and burn with a steady
blue flame.
DAMPER POSITION INDICATOR
MUST BE IN VISIBLE LOCATION
FOLLOWING INSTALLATION.
OPEN
CLOSED
FLOW DIRECTION
FIGURE 2.2
DANGER:If flame rollout switch or spill switch trips
repeatedly during start-up or operation, it indicates
a hazardous condition to be corrected immediately.
WARNING: If boiler cannot be restored to normal
operation after resetting of spill switch, or if flame
rollout switch has tripped, do not attempt to put the
boiler in operation. Immediately contact a qualified
service professional.
WARNING: Keep boiler area clear and free from com-
bustible materials, gasoline and other flammable
vapors and liquids. Otherwise, fire or explosion may
result.

16
9. Boilers are shipped from the factory with the primary
air shutters on the main burner wide open. It is recom-
mended these air shutters be left in the wide open posi-
tion unless there is lifting of the flame above the burner
ports. If there is lifting, the air shutters should be gradu-
ally closed until the lifting is eliminated. It may also be
necessary to adjust the primary air shutters if the input
rate is reduced by a change in the orifices.
10. After boiler has been in operation for about 10 min-
utes, check gas input rate to boiler as follows:
a. Make sure that all appliances served by meter are
turned off during timing of gas input rate to the boiler.
b. Measure the time in seconds it takes for the boiler
to use10 cubic feet of gas. Divide 36,000 by the num-
ber of seconds (this is the number of cubic feet of gas
used per hour). Multiply this figure by the heating
value of the gas to obtain Btu input per hour.
Example: An HC-120D boiler takes 5 minutes, 6 sec-
onds to use 10 cubic feet of natural gas. Local utility
indicated heating value of the natural gas being sup-
plied is 1020 Btu/cu ft. Therefore:
6+ (5x60) = 306 seconds
36,000 x 1020 = 120,000 Btu/hr
306
Therefore, the boiler input is correct.
NOTE: Before calculating the input of the heating
equipment, obtain the heating value of the gas from
the local utility.
11. If boiler input needs to be corrected, adjust the com-
bination gas valve pressure regulator. (Regulator is fac-
tory set at 3.5" W.C. for natural gas or 10" W.C. for
propane.) Turn adjusting screw clockwise to increase
gas flow (increase input). Turn adjusting screw counter-
clockwise to decrease gas flow (decrease input). In no
case, should final manifold pressure setting vary more
than .2" W.C. from factory-set pressures. If rated input
cannot be obtained with regulator adjustment, gas sup-
ply pressure or orifice size may be the cause. Consult
your local utility and Hydrotherm.
12. The gas burner orifices supplied with the boiler have
been carefully designed to provide the correct gas input
rate for most gas conditions typically found in the U.S.
Occasionally, however, the local gas characteristics may
not allow the unit to be properly adjusted for input. If this
is the case, the local utility or Hydrotherm may recom-
mend the orifices be changed. When changing orifices,
follow the procedures in Section 3 of this manual.
13. Start and stop boiler several times by raising and
lowering the thermostat setting.
14. After the boiler has been firing long enough to raise
the boiler water temperature to above the minimum set-
ting of the high limit, check the high limit by turning its
setting from maximum to minimum setting. This should
turn the boiler off. Return high limit to desired setting.
15. With the boiler firing, disconnect the wire connected
to the "PV" terminal on Honeywell S8600 control. Gas
valve should close.
Q345ALB
INTERMITTENT
IGNITION PILOT
MODELS
NORMAL PILOT FLAME
NORMAL
(HARD FLAME) LIFTING
(TOO MUCH AIR) YELLOW
TIPPING
(MARGINAL)
MAIN BURNER FLAMES
YELLOW
FLAME
(TOO LITTLE AIR)
FIGURE 2.3
WARNING: Never leave the job with yellow burning
flames. This condition indicates poor combustion
and will quickly carbonize the boiler, reducing effi-
ciency and boiler life. It may also be an indication of
improper venting or combustion air supply. If
unable to adjust flame properly, consult your local
utility. Failure to comply with this warning can result
in severe personal injury or death!

17
WARNING
If you do not follow these instructions exactly, a fire or explosion may result
with property damage, personal injury, or loss of life.
A. This appliance is equipped with an ignition device which
automatically lights the pilot. Do NOTtry to light the pilot by
hand.
B. BEFORE OPERATING, smell all around the appliance area
for gas. Be sure to smell next to the floor because some gas is
heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any phone
in your building.
• Immediately call your gas supplier from a neighbor's
phone. Follow the gas supplier's instructions.
• If you cannot reach your gas supplier, call the fire
department.
C. Use only your hand to turn the gas control knob. Never use
tools. If the knob will not turn by hand, don't try to repair it, call a
qualified service technician. Force or attempted repair may
result in a fire or explosion.
D. Do not use this appliance if any part has been under water.
Immediately call a qualified service technician to inspect the
appliance and to replace any part of the control system and any
gas control which has been underwater.
OPERATING INSTRUCTIONS
Intermittent Pilot - Honeywell VR8204
Natural or Propane Gas
1. STOP! Read the safety information above.
2. Set the thermostat to lowest setting.
3. Turn off all electric power to the appliance.
4. This appliance is equipped with an ignition device which
automatically lights the pilot. Do NOTtry to light the pilot by
hand.
5. Turn gas control knob clockwise to "OFF". Do not force.
6. Wait five (5) minutes to clear out any gas. Then smell for
gas, including near the floor. If you then smell gas, STOP!
Follow "B" in the safety information above. If you don't smell
gas, go to next step.
7. Turn gas control knob counterclockwise to "ON".
8. Turn on all electric power to the appliance.
INLET
GAS CONTROL KNOB
SHOWN IN "OFF" POSITION
GAS ON
OFF
9. Set thermostat to desired setting.
10. If the appliance will not operate, follow the instructions "TO
Turn Off Gas To Appliance" and call your service techni-
cian or gas supplier.
TO TURN OFF GAS TO APPLIANCE
1. Set the thermostat to lowest setting.
2.Turn off all electric power to the appliance if service is
to be performed.
3. Turn gas control knob clockwise to "OFF". Do not
force.
FIGURE 2.4

18
SECTION 3: MAINTENANCE
This boiler has been designed to provide years of trou-
ble free performance in normal installations. Examina-
tion by the homeowner at the beginning of each heating
season, and in mid-heating season, should assure con-
tinued good performance. In addition, the boiler should
be examined by a qualified service professional at least
once every year.
NOTE: Boiler is not for use in systems where water
is replenished. Do not draw water from system for
cleaning. Minerals in water can build up on heat
transfer surfaces and cause overheating and subse-
quent failure of cast iron sections.
NOTE: If boiler is equipped with a low water cutoff,
follow manufacturer's maintenance instructions.
WATER TREATMENT
Water treatment is recommended in areas where water
quality is a problem. A local water treatment company
should be consulted to determine the requirements for
your particular system and locality.
FREEZE PROTECTION
Where absolutely necessary, system antifreeze can be
utilized. It must be compatible with hydronic heating sys-
tems. System must be designed to accommodate nec-
essary changes in heat transfer, pump head, flow rate &
expansion. For more information, consult The Hydronics
Institute Technical Topics Number 2A publication.
NOTE: Never use an RV-type antifreeze protection
solution nor an automotive-type antifreeze as dam-
age to the boiler and other system components may
result.
BEFORE EACH HEATING SEASON
1. Remove and inspect draft hood and vent piping (con-
necting draft hood to chimney or vent) for obstructions,
soot accumulation, rust or corrosion. Clean and replace
as necessary. Check tightness of joints; seal all joints
where necessary.
2. Check boiler flue passageways in the boiler sections
for any blockage or soot accumulation. Remove draft
hood, jacket top and cast iron dome. Using a flash light,
examine all flue passageways.
a. If passageways are free of soot and obstructions,
replace dome and seal with furnace cement or high
temperature silicone adhesive/sealant.
b. If passageways need cleaning, remove burners as
described in paragraph 3 below. Insert long-handle
bristle flue brush down between section tubes and
upward through sections from combustion chamber in
both diagonal directions to remove carbon from fin-
ned surfaces. Vacuum debris. Replace dome and
seal with furnace cement or high temperature silicone
adhesive/sealant.
c. Reinstall jacket top panel and draft hood.
3. Check and clean burner assembly. Remove burner
access panel. To remove burners, lift up and to rear until
burners are disengaged from orifices. Brush top of burn-
ers with soft bristle brush; blow out with air or vacuum.
4. Check gas manifold for proper position and reassem-
ble burners to the manifold. Line up holes in burners
with the orifices and slide assembly back into position.
BE SURE TO REINSTALL BURNER WITH PORTS ON
THE TOP SURFACE (UPRIGHT).
5. When a low water cut-off has been utilized, follow the
manufacturer’s maintenance instructions. As a mini-
mum, test electronic control operation at least once a
year. Float type controls should be flushed twice a year.
6. Lubricate circulator motor according to manufacturer's
instructions. This information may be contained in label-
ing on the pump frame.
7. Follow "System Start-Up & Adjustments" procedures
in Section 2 of this manual.
DANGER: To avoid fire and explosion hazards: Do
not store anything against boiler or allow dirt/debris
to accumulate in area immediately surrounding boil-
er. Keep boiler area clear and free from combustible
materials, gasoline and other flammable vapors and
liquids. Do not allow lint, paper or rags to accumu-
late near burners. Do not place clothing on boiler to
dry. Do not obstruct the flow of combustion and
ventilation air.

19
HOW TO CHANGE ORIFICES
1. Shut off power supply and gas supply to the boiler.
2. Remove burner access panel. To remove burners, lift
up & to rear until burners are disengaged from orifices.
3. Check orifices for proper drill size. Size is stamped
onto the body of the brass orifice. The size can also be
checked by using a pin gauge (see Figure 3.1). All ori-
fices are screwed into the manifold and may be removed
by using a 5/8" wrench or socket. 4. Reverse above procedures to install orifices & burn-
ers. BE SURE TO INSTALL BURNERS WITH BURNER
PORTS ON TOP SURFACE (UPRIGHT).
MODEL
HC-65
NAT. GAS
DRILL SIZE
2.60MM
32
37
40
35
32
L.P. GAS
DRILL SIZE
52
49
1.65MM
1.55MM
51
1.85MM
HC-85
HC-100
HC-120
HC-145
HC-165 FIGURE 3.1
NO HEAT
1. Blown fuse or circuit breaker.
2. Power switch turned off.
3. IID system malfunction.
4. Vent damper not open.
5. Circulator not running.
6. Air in lines and radiation.
7. Tripped rollout switch.
8. Tripped spill switch.
INSUFFICIENT HEAT
1. Incorrect t'stat anticipator setting.
2. Hi-limit control setting too low.
3. Boiler undersized or underfired.
4. Insufficient radiation.
5. Air traps in lines or radiation.
OVERHEATING
1. Wrong thermostat anticipator set-
ting.
2. Bad thermostat location.
3. Bad thermostat.
ODOR, EXCESSIVE MOISTURE IN
BUILDING
1. Leak in piping.
2. Carbon build-up in flueways.
3. Blocked chimney.
4. Downdrafts- incorrect termination
YELLOW FLAME, CARBON
BUILD-UP
1. Unit overfired.
2. Air shutter misadjustment
3. Wrong orifices.
4. Burning in burner mixing tube.
5. Inadequate combustion air.
6. Inadequate draft (flue blockage).
NOISE
1. Ignition-incorrect air shutter adjust-
ment
2. Whistle due to burr on orifices.
3. Burner "fluteing" -air shutter open-
ing too wide.
TROUBLESHOOTING
CAUTION:
Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dan-
gerous operation.
Verify proper operation after servicing.
Orifice Size
Model # Fuel Type Orifice Qty. Sea Level 2000 ft. 3000 ft. 4000 ft. 5000 ft. 6000 ft. 7000 ft. 8000 ft. 9000 ft. 10000 ft.
HC-65D,E NG 2 2.60mm 39 40 41 41 42 42 43 43 44
HC-65D,E LP 2 52 52 53 53 53 53 53 54 54 54
HC-85D,E NG 2 32 33 34 35 35 36 36 37 38 40
HC-85D,E LP 2 49 50 50 50 51 51 51 52 52 52
HC-100D,E NG 3 37 38 39 39 40 41 42 42 43 43
HC-100D,E LP 3 1.65mm 52 53 53 53 53 53 54 54 54
HC-120D NG 4 40 41 42 42 42 43 43 44 44 46
HC-120D LP 4 1.55mm 54 54 54 54 54 54 55 55 55
HC-125E NG 4 39 40 41 41 42 42 43 43 44 44
HC-125E LP 4 1.60mm 1.60mm 53 53 53 53 53 54 54 54
HC-145D,E NG 4 35 36 36 37 37 38 39 40 41 42
HC-145D,E LP 4 51 51 52 52 52 52 53 53 53 54
HC-165D,E NG 4 32 33 34 35 35 36 36 37 38 40
HC-165D,E LP 4 1.85mm 50 50 50 51 51 51 52 52 52
EQUIVALENT ORIFICE SIZES AT HIGH ALTITUDES (INCLUDES 4% INPUT REDUCTION FOR EACH 1,000 FEET)
NOTE: For orifice part numbers, see "Orifice Part Numbers" chart on page 24.

20
APPENDIX A
S'ASSURER QUE
LE MOTEUR SOIT
SITUÉ A GAUCHE
1. Monter le volet de ventilation sur la partie
supèrieure du coupe-tirage.
'
MONTER LE VOLET
DE VENTILATION
AU-DESSUS DU COUPE-
TIRAGE.
LA FLÈCHE DE DIRECTION
DE L'ÈCOULEMENT POINTE
VERS LE HAUT
FIGURE 3.2
MÈTHODE D' INSTALLATION B: pour le volet motorisé de ventilation.
DANGER: Le volet de ventilation doit servir seulement à la chaudière. Ne pas l utiliser
pour ventiler d'autres appareils; sinon cela pourrait provoquer un incendie ou causer un
empoisonnement par le monoxyde de carbone.
2. Fixer le volet de ventilation au coupe-tirage.
FIGURE 3.3
ATTACHER LA PARTIE
INFÉRIEURE DU VOLET
DE VENTILATION AU
COUPE-TIRAGE À L'AIDE
DE VIS DE 1/2 po OU PLUS
COURTES OU DES RIVETS
AVEUGLES.
FIGURE 3.4
FAISCEAU DE FILS
DU VOLET DE
VENTILATION.
3. Brancher le faisceau de fils.
ENFICHER DANS LA PRISE
MOLEX SUR LE DEVANT
DE LA CHAUDIÉRE.
ENFICHER DANS LA PRISE
MOLEX À L'NTERIÉUR DU
MOTEUR DU VOLET DE
VENTILATION.
LE REGISTRE DOIT ÊTRE EN
POSITION OUVERTE LORSQUE
LE BRÛLEUR PRINCIPAL EST EN
MARCHE.
OUVERTE
CLOS
SENS DE DEBIT
FIGURE 3.5