Hastings IHR SERIES Manual

Installation and Service Manual
“IHR/ISHR/HR/HRDV/R” SERIES
INDOOR/OUTDOOR SYSTEMS AND
INDIVIDUAL DUCT FURNACES
Notice
Read These Instructions Before Installation
Inspect unit on arrival for any shipping damage. This unit has been
test fired for at least 15 minutes to prove out all phases of operation.
If any part is missing or damaged, notify the carrier at once.
ISIRHS-1
February 2010
WARNING
FOR YOUR SAFETY
If you smell gas:
1. Open windows
2. Don’t touch electrical switches
3. Extinguish any open flame.
4. Immediately call gas supplier
FOR YOUR SAFETY
The use and storage of gasoline or
other flammable vapors and liquids in
open containers in the vicinity of this
appliance is hazardous.
WARNING: Improper installation, adjustment, alteration, service or
maintenance can cause injury or death. Read the installation, opera-
ting and maintenance instructions thoroughly before installing or
servicing this equipment.

TABLE OF CONTENTS
Page
HRDV Dimension………………………………………………………………………………………. 1
(IH) (ISH) (H) RHF (IH) (ISH) (H) RMU and ((IH (ISH) (H) RHV Unit Dimensions..................... 2-3
(H) RHF and (H) RHV Unit Dimensions with Optional Intake and Discharge
Plenums and Curbs……………………………………………………………........................... 3-4
(H) RMU and (H) RHV Unit Dimensions with Optional Discharge
Plenums and Curbs………………………………………………………………........................ 5-6
Shipping…………………………………………………………………………………………………. 6
Hoisting Unit……………………………………………………………………………………………. 6
Installation………………………………………………………………………………………………. 7
Location…………..……………………………………………………………………………………... 8-9
Electrical………………………………………………………………………………………………… 9
Venting………………………………………………………………………………………………….. 10-12
Gas Supply Piping……...……………………………………………………………………………… 13-14
Operation of Mechanical Modulating Valve…………………………………………………………. 15
Operation of Electronic Modulating Valve…………………………………………………………… 16
Maintenance…………………………………………………………………………………………… 16-22
Model and Serial Number can be found on equipment spec. plate located on
blower cabinet side.
Model # _____________________________________________________
Serial # ______________________________________________________
Date of Purchase ______________________________________________
Purchased from _______________________________________________

“HRDV DUCT FURNACE”
Dimensions
ISHRDV, IHRDV, HRDV MODEL NO.
100 125 160 210 250 300 400
A30 5/8 30 5/8 41 3/8 41 3/8 52 1/16 52 1/16 65 1/2
AA - - - - - - -
B18 18 28 3/4 28 3/4 39 1/2 39 1/2 52 7/8
BB - - - - - - -
C21 7/8 21 7/8 32 5/8 32 5/8 43 3/8 43 3/8 56 7/8
CC - - - - - - -
D6 6 6 6 6 6 6
DD (2) 6 (2) 6 (2) 6 (2) 6 (2) 6 (2) 6 (2) 6
NOTE: All dimensions in inches. Check installation manual for recommended clearances.
*Indoor Separated Combustion model will have (1) venter outlet and (1) combustion air inlet per duct furnace.
ISHRDV, IHRDV, HRDV MODEL NO.
500-A 500-B 600-A 600-B 800-A 800-B
A- 52 1/16 - 52 1/16 - 65 1/2
AA 104 1/8 - 104 1/8 - 131 -
B- 39 1/2 - 39 1/2 - 52 7/8
BB 87 3/4 - 87 3/4 - 114 5/8 -
C- 46 3/8 - 43 3/8 - 56 7/8
CC - - 69 5/8 - 74 5/8 -
D(2) 6 (2) 6 (2) 6 (2) 6 (2) 6 (2) 6
DD (4) 6 (4) 6 (4) 6 (4) 6 (4) 6 (4) 6
NOTE: All dimensions in inches. Check installation manual for recommended clearances.
*Indoor Separated Combustion model will have (1) venter outlet and (1) combustion air inlet per duct furnace.
1

2

R
ETURN AIR DUCT
C
ONNECTION - 1" FLANGES
T
URNED UP
F
LANGE AROUND
P
ERIMETER OF PLENUM
B
ASE FRAME SERVES AS
C
URB COUNTER FLASHING
R
EAR VIEW
S
IDE ELEVATION
FRONT VIEW
F
D
E
1
7-1/2
L
OUVER
A
SSEMBLY
R
EMOVABLE PANEL FOR DUCT
CONNECTION AND INSPECTION
D
RAIN PAN
F
RESH AIR INTAKE WITH BIRDSCREEN
O
PTIONAL
M
IXING
D
AMPERS
B
LOWER
S
ECTION
INLET
P
LENUM
DUCT
F
URNAC
E
BANK A
DUCT
F
URNACE
BANK B
D
ISCHARGE
PLENUM
REMOVABLE PANEL FOR
DUCT CONNECTION AND
INSPECTION
D
ISCHARGE AIR
D
UCT CONNECTION
-
1
" FLANGE TURNED
U
P
3
/8
F
1
7-1/2
1
-1/2
G
(IH) (ISH) (H) RHFA - (IH) (ISH) (H) RMUA (IH) (ISH) (H) RHFB - (IH) (ISH) (H) RMUB
(IH) (ISH) (H) RHVA (IH) (ISH) (H) RHVB
100 160 250 400 600 800 200 320 500 800 1000 1600
125 210 300 250 420 600 1200
A 73 80 80 83 90 90 103-1/2 110-1/2 110-1/2 113-1/2 120-1/2 120-1/2
B 30-5/8 41-3/8 52-1/8 65-1/2 131 131 30-5/8 41-3/8 52-1/8 65-1/2 131 131
C 13-3/4 13-3/4 13-3/4 13-3/4 15-1/2 15-1/2 13-3/4 13-3/4 13-3/4 13-3/4 15-1/2 15-1/2
D 19-1/2 30-1/4 41 47-3/8 113-3/8 113-1/8 19-1/2 30-1/4 41 47-3/8 113-3/8 113-3/8
E 68-1/2 75-1/2 75-1/2 78-1/2 85-5/8 85-5/8 98-7/8 105-7/8 105-7/8 108-7/8 116-1/4 116-1/4
F 17-7/8 28-5/8 39-3/8 52-3/4 114-1/2 114-1/2 17-7/8 28-5/8 39-3/8 52-3/4 114-1/2 114-1/2
G 21-7/8 32-5/8 43-3/8 56-3/8 118-5/8 118-5/8 21-7/8 32-5/8 43-3/8 56-3/8 118-5/8 118-5/8
H 14-1/4 16 19-3/8 19-7/8 19-3/8 19-7/8 14-1/4 16 19-3/8 19-7/8 19-3/8 19-7/8
J 6-1/2 6-1/2 6-1/2 10 11-3/4 11-3/4 6-1/2 6-1/2 6-1/2 10 11-3/4 11-3/4
N
OTES:
1
. Duct dimensions are approximate. Certified prints furnished on request.
Truck - Base unit factory assembled except for gravity vent caps and remote mounted controls
.
O
ptional roof curb, evaporative cooling air washer section or RHFA, RMUA, RHVA 500, 600, 800 and RHFB, RMUB, RHVB
1
000, 1200, 1600 Intake hood with birdscreen shipped in separate crate. Downstream duct furnaces on all 1000, 1200, 1600
m
odels shipped in separate crate.
S
HIPPING INFORMATION:
"
HR/R" OUTDOOR SYSTEMS
D
imensions - (H) RHF and (H) RHV Models with Intake and Discharge Plenums.
3

D
imensions - Roof Curbs for Intake and
Discharge Plenums.
O
UTLINE OF UNIT WITH PLENUMS
3
/8
B
LOWER SUPPORT
F
URNISHED FOR
(
H) RHVA 600 AND 800
A
ND (H) RHVB-1000
T
HRU 1600 MODELS
O
NLY.
O
UTLINE OF UNIT WITH PLENUMS
19-1/2
2
4-3/4
H
J
C
21-3/4
19-1/2
3
/8
R
OOF LINE
E
LEVATION
P
LAN VIEW
I
NLET
C
URB
1
6
B
LOWER
S
UPPORT
D
ISCHARGE
CURB
P
lenum-Curb Relationship
R
ear Support-Curb Relationship
U
NIT BASE SIDE
C
HANNELS
N
EOPRENE STRIP
1
" INSULATION
1
/2 X 3-1/8
N
EOPRENE SEALING
STRIP
1
" INSULATION
W
OOD NAILER
C
URB
F
RAME
P
LENUM FRAME
A
LL PARTS SHOWN ARE FURNISHED WITH CURBS
N
OTES:
1
. Inlet plenum is shown for units with mixing
dampers. This includes louver assembly,
drain pan and fresh air intake with birdscreen
.
For 100% return air applications, inlet plenum
furnished without louver assembly and drain
pan. Birdscreen is replaced with cover plate
.
2
. Duct Furnace Bank B furnished with (H)
RHFB - (H) RHVB models only.
3
. Standard flashing and mopping procedures
are recommended for curb openings and
gas and electrical roof penetrations.
4
. Deck curb available to provide covered island
under complete unit with openings for supply
and return air
(H) RHFB - (H) RHVA (H) RHFB - (H) RHVB
100 & 125 160 & 210 250 & 300 400 600 & 800 200 & 250 320 & 420 500 & 600 800 1000 & Up
A 20-15/16 31-11/16 42-7/16 55-7/8 117-7/16 20-15/16 31-11/16 42-7/16 55-7/8 117-7/16
B 24-7/16 35-3/16 45-15/16 59-3/8 120-15/16 24-7/16 35-3/16 45-15/16 59-3/8 120-15/16
C 74-3/4 81-3/4 81-3/4 84-3/4 92 105-3/16 112-3/16 112-3/16 115-3/16 122-7/16
D 82 89 89 92 99-3/16 112-7/16 119-7/16 119-7/16 122-7/16 129-5/8
E 126 133 133 136 143-3/16 156-7/16 163-7/16 163-7/16 166-7/16 173-5/8
F 17-3/16 27-15/16 38-11/16 52-3/16 113-15/16 17-3/16 27-15/16 38-11/16 52-3/16 113-15/16
G 3/8 3/8 3/8 3/8 1/4 3/8 3/8 3/8 3/8 1/4
H - - - - 23 - - - - 23
J - - - - 48 - - - - 60
4
A
B

"
HR/R" OUTDOOR SYSTEMS
D
imensions - (H) RMU and (H) RHV Models with Discharge Plenums Only.
F
RESH AIR INTAKE
W
ITH BIRDSCREEN
O
PTIONAL
INTAKE
DAMPER
B
LOWER
S
ECTION
DUCT
F
URNAC
E
BANK A
DUCT
F
URNACE
BANK B
D
ISCHARG
E
PLENUM
E
F
1
7-1/2
G
D
ISCHARGE AIR DUCT
C
ONNECTION - 1"
F
LANGE TURNED UP
R
EMOVABLE PANE
L
F
OR DUCT
C
ONNECTION AND
INSPECTION
F
LANGE AROUND PERIMETER
O
F PLENUM BASE FRAME
S
ERVES AS CURB
C
OUNTER FLASHING
S
EE NOTE
4
R
EAR VIEW
S
IDE ELEVATION
FRONT VIEW
D
imensions - Roof Curbs for Discharge
Plenums Only.
O
UTLINE OF UNIT WITH DISCHARGE PLENUM
B
A
3
/8
R
EAR SUPPORTS FOR
(
H) RMUA 600 AND 80
0
A
ND (H) RMUB-1000
T
HRU 1600
D
K
J
C
1
9-1/2
2
4-3/4
R
EAR SUPPORT FOR
(
H) RMUA-100 THRU
4
00 AND (H) RMUB-60
0
A
ND 800
P
LAN VIEW
O
UTLINE OF UNIT WITH
D
ISCHARGE PLENUM
1
6
D
ISCHARGE
CURB
ROOF LINE
E
LEVATION
P
lenum-Curb Relationship
PLENUM FRAME
1
" INSULATION
1
/2 X 3-1/8 NEOPRENE
SEALING STRIP
1
" INSULATION
CURB
F
RAME
W
OOD NAILER
R
ear Support-Curb Relationship
U
NIT BASE
S
IDE CHANNELS
NEOPRENE STRIP
3
-1/2"
A
LL PARTS SHOWN ARE FURNISHED WITH CURBS.
N
OTES:
1
. Duct Furnace Bank B furnished with RMUB-RHVB models only.
2
. Standard flashing and mopping procedures are recommended for curb opening, rear support, and gas and electrical
roof penetrations.
3
. Deck curb available to provide covered island under complete unit with opening for supply air.
4
. High air delivery may necessitate a second Fresh Air Damper and/or Intake Hood with Birdscreen. Check Pressure
Drop Chart on page 3 and Blower Motor Capability on page 4.
5
3
/8

(H) RMUA – (H) RHVA (H) RMUB – (H) RHVB
100 & 125 160 & 210 250 & 300 400 600 & 800 500 & 600 800 1000 & Up
A20-15/16 31-11/16 42-7/16 55-7/8 117-7/16 42-7/16 55-7/8 117-7/16
B24-7/16 35-3/16 45-15/16 59-3/8 120-15/16 45-15/16 59-3/8 120-15/16
C63 67 67 70 - 97-7/16 100-7/16 -
D23-3/16 33-15/16 44-11/16 58-1/8 - 44-11/16 58-1/8 -
E77-1/2 84-1/2 84-1/2 87-1/2 94-19/32 114-15/16 117-15/16 125-1/32
F99-1/2 106-1/2 106-1/2 109-1/2 116-19/32 136-15/16 139-15/16 147-1/32
G17-3/16 27-15/16 38-11/16 52-3/16 113-15/16 38-11/16 58-3/16 113-15/16
H3/8 3/8 3/8 3/8 1/4 3/8 3/8 1/4
J- - - - 33-1/16 - - 63-1/2
K- - - - 36 - - 36
SHIPPING
The unit is shipped by either common carrier or flat bed trailer. Consult with the factory on number of sections per load.
1. TRUCK – The intake hood with Birdscreen is shipped in a separate crate on all Outdoor (H) RHFA, (H) RMUA,
(H) RHVA-500, 600, and 800 and Outdoor (H) RHFB, (H) RMUB, (H) RHVB-1000, 1200 and 1600
systems. Downstream heaters of all Outdoor/Indoor (IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH)
(ISH (H) RHVB-1000, 1200, and 1600 are shipped in a separate crate.
2. The remote control panel, when provided, is shipped unmounted.
HOISTING UNIT
1. The weight of the systems is shown in Table I.
TABLE I
Unit MaximumWeight,Lbs.*
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 100 1115
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 125 1155
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 160 1200
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 210 1285
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 250 1560
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 300 1625
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 400 1840
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 600 3350
(IH) (ISH) (H) RHFA, (IH) (ISH) (H) RMUA, (IH) (ISH) (H) RHVA – 800 3880
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 200 1445
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 250 1525
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 320 1610
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 420 1800
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 500 2025
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 600 2125
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 800 2545
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 1000 4520
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 1200 4800
(IH) (ISH) (H) RHFB, (IH) (ISH) (H) RMUB, (IH) (ISH) (H) RHVB – 1600 5765
*This weight is the maximum that would be encountered on the system with all available options installed. If
a specific weight is required, contact the manufacturer, or consult catalog.
2. At least four (4) lines (minimum) and suitable spreaders should be used to lift the unit, or flat platform lift with
proper lifting weight ability should be used. Unit must be slinged properly with multiple lifting points to prevent
the unit from sagging.
3
. On units with either inlet or discharge plenums, or both, suitable slings must be provided for support beneath
the unit. A minimum of four support slings are required. Additional sling supports may be needed for long
pieces of equipment.
WARNING – The mechanical or structural engineer should becontacted before moving unit across the roof deck.
6

INSTALLATION
1. The unit may be installed on a field fabricated mounting frame or support, a factory roof curb mounting frame or
a slab. The following items are important in this regard:
A. Be sure that roof joist or support will not interfere with discharge and return air ducts.
B. Be sure frame or support is square, level and not twisted.
C. Field fabricated frame, support, or slab must be high enough to prevent any form of moisture from enter-
ing unit.
D. All joints on frame must be sealed with caulking compound.
E. Field fabricated curb should be insulated with at least 1 ½” thick rigid type insulation.
F. The roof curb should be counterflashed and sealed before unit is installed.
G. HRDV duct furnace must be installed on the positive side of air supply blower. The blower must provide
air through-put within range specified on the appliance spec plate.
2. The discharge and return air duct (if required) should be correctly sized for securing to factory installed plenums,
when provided, or to unit. Duct connection(s) exposed to the weather must be watertight. A weather tight seal
must be provided where duct(s) comes through the roof.
3. An HRDV duct furnace shall be installed with an inlet duct which will provide air distribution equivalent to a straight
run of duct having the same cross-sectional area as the inlet connection and not less than 2 equivalent diameters in
length.
4. Installation of HRDV duct furnaces shall specify that the ducts connected to the duct furnace shall have removable ac-
cess panels on both upstream and downstream sides of the duct furnace. These openings shall be accessible when
the appliance is installed in service, and shall be of such size that smoke or reflected light may be observed inside the
casing to indicate the presence of leaks in the heating element. The cover for the opening shall be attached in such a
manner as to prevent leaks.
WARNING
INSTALLATION PRECAUTIONS:
NOTE: GUARANTEE OF THIS EQUIPMENT IS SUBJECT TO CONFORMANCE WITH THE FOLLOWING:
1 Heater Location Requirements:
a. Outdoor units with poor venting, pilot outage, and other undesirable operating conditions may be caused by a
negative pressure condition or high pressure zones created by walls or other obstructions. Therefore, the furnace
must be located as far as possible from the source of such turbulence and at least six feet from the edge of the roof.
b. Indoor units must NOT be operated in the presence of CHLORINATED SOLVENTS. Even slight traces of chlorine
combined with products of combustion will cause serious damage.
c. Indoor units must have adequate COMBUSTION AIR. If heaters are installed in a closed room, provide outside
opening of one square inch per 1,000 BTU for combustion air alone.
d. Indoor units must not operate in an area with a negative air pressure condition. Provide adequate MAKE-UP AIR.
e. Indoor units installed where there is sawdust, lint, soot, dirt, etc., areas of high air contamination, must be cleaned
FREQUENTLY or serious damage will result. Refer to section on CLEANING for recommended frequency.
2. WARNING: Installer/Service Technician must remove burner tray to inspect burner assemblies, to insure proper
alignment. Prior to installing gas supply line to unit gas inlet, remove the “L” locking bracket and disconnect the
electrical connections and slide the burner tray out of the heater. Once inspection is completed, replace the burner
tray assembly and install the “L” locking bracket. Failure to perform this inspection could result in fire,
explosion, loss of warranty, or even death.
3. Firing rate must NOT be increased above the BTU input shown on the specification plate.
4. For U.S. installations at elevations above 2,000 feet (610 M), the appliance shall be derated 4 percent for each 1,000
feet (305 M) of elevation above sea level. For Canadian installations, appliances are certified for altitudes of 0 to
2,000 feet (0-610 M) and 2,000 to 4,500 feet (610-1,370 M). High altitude ratings may be obtained by a change in
orifice size and/or manifold pressure. Contact the manufacturer or gas company before changing spud sizes or
pressure regulator setting. Use ½ inch socket wrench to remove spuds. NOTE: L.P. GAS UNITS ARE EQUIPPED
WITH SPECIAL TAPER REAMED SPUDS WHICH MUST NOT BE RESIZED IN THE FIELD.
5. Air starvation is a common cause of heat exchanger burn out. Air handling system design MUST POSITIVELY
ASSURE adequate and evenly distributed air flow through the heat exchanger. See ILLUSTRATIONS on page 15.
6. The furnace must be installed downstream from or on the POSITIVE PRESSURE SIDE of the air circulating blower
7

7. Air flow through the furnace may be in either direction. However, on units with an air distribution baffle assembly, the
air flow must enter the furnace from the baffle side. If entering air is desired from the opposite side, the baffle
assembly must be relocated to that side of the heat exchanger. High SCFM models do not require this baffle
assembly and are recognized by the suffix letter “H” in the furnace model number. (Example: IHRDV-400HME).
8. High SCFM model furnaces require heating air temperature rise be maintained at between 10º to 60º F. On units with
the baffle assembly temperature rise must be maintained between 40º to 100º F. Units must not be adjusted to obtain
temp. rise above thee ranges.
9. Filters, if used, must be cleaned or replaced as often as is necessary so as not to restrict air delivery.
10. Furnaces installed in areas of high air contamination may require FREQUENT cleaning. Refer to section on
CLEANING for recommended frequency.
11. The (I) (IS) HRDV furnaces are design certified for operation with modulating or two-stage gas controls. When either
modulating or two-stage controls are ordered, a thermostatic type fan control switch must NOT be used. With these
gas controls, constant fan operation, simultaneous fan and gas valve operation, or a fan time delay relay must be
employed.
12. If a fan control is not used, the blower must operate continuously or whenever the gas valve opens.
NOTE: AS AN ADDED PRECAUTION, INSTALL EITHER AN AIR PROVING SWITCH OR A
SINGLE POLE, NORMALLY OPEN RELAY IN THE ELECTRIC GAS VALVE CIRCUIT. THE
AIR PROVING SWITCH WOULD SENSE AIR CIRCULATION THROUGH THE SYSTEM.
THE RELAY WOULD BE ENERGIZED BY THE LOAD SIDE OF THE BLOWER MOTOR
STARTER. EITHER SWITCH WOULD THEN ACTIVATE THE GAS VALVE TO OPEN, BUT
ONLY WHEN THE BLOWER WAS OPERATING.
13. The high limit control switch is a safety control that provides protection if furnace overheats due to blower failure,
restricted air flow, or faulty controls. If unit overheats the limit switch breaks the circuit to the electric gas valve and
closes gas supply. When the temperature of the heat exchanger drops to a safe degree, the limit switch automatically
rests and permits the gas valve to open again. Cause of trouble must be corrected IMMEDIATELY to avoid serious
damage to the furnace. The limit switch is a safety control, NOT AN OPERATING CONTROL.
14. Special precautions for furnaces used in conjunction with AIR COOLING and MAKE-UP AIR SYSTEMS:
a. Type 409 STAINLESS STEEL heat exchangers may be used in all applications, but is recommended for make up
air systems where inlet air temperature is ABOVE 40º F.
b. If furnace is used in either make-up air or air cooling applications, significant quantities of condensate may form.
15. Field installed ductwork on the unit discharge end must be secured to the flanges on the heat exchanger and not on
unit front cabinet. Failure to properly install could cause fire, explosion, damage to equipment or even death.
16. Venting (I) ISHRDV indoor duct furnaces. Venting must be installed by a qualified installer in accordance with all local
codes. In the absence of local codes, venting must be installed in accordance with the latest edition of the National
Fuel Gas Code, ANSI Z223.1/NFPA#70, Part 7, venting of equipment. In Canada, venting must be in accordance
with the latest edition of the Natural Gas Installation Code CAN/CGA-B149.1; propane installation code CAN./CGA-
BA49.2. A built-in power venter is provided – do not connect into any additional mechanical draft systems operating
under a positive pressure. Improper installation can create a hazardous condition such as explosion, fire, carbon
monoxide poisoning, resulting in property damage, personal injury or death.
INSTALLATION:
· Regulations:
Installation of this appliance must conform to applicable federal, state, and local codes and regulations, and with guidelines established by
A.G.A (American Gas Association), NFPA(National Fire Protection Association), N.E.C. (National Electrical Code), the National Board of Fire
Underwriters and CAN/CGA B149. Listed are codes appearing in this text, the Associations, and their addresses where they may be
obtained.
1. The National Fuel Gas Code 2. All NFPA codes, National Electrical Code
Contact: American Gas Association (Administrative) Contact: National Fire Protection Association, Inc.
1515 Wilson Boulevard Batterymarch Park
Arlington, Virginia 22209 Quincy, Massachusetts 02269
3. Standard of National Board of Fire Underwriters 4. Canadian Gas Association
Contact: National Board of Fire Underwriters Contact: Canadian Gas Association
85 John Street 178 Rexdale Boulevard
New York, New York 10036 Etobicoke, Ontario, Canada M9W 1R3
LOCATION
NOTE: AMERICAN INSTALLATIONS MUST CONFORM WITH THE NATIONAL FUEL GAS CODE
(AMERICAN NATIONAL STANDARD ANSI Z223.1/NFPA54 – “Latest Revisions”) AND ALL
APPLICABLE GOVERNING BUILDING CODES. CANADIAN INSTALLATIONS MUST CONFIRM
WITH CAN/CGA B149 – “Latest Revisions”.
8

1. The (I) (IS) HRDV Furnace has been designed for INDOOR OR HRDV FOR OUTDOOR INSTALLATIONS.
2. Refer to items 1, 2, 5, 6, 9, 10 12, 15, and 16 of INSTALLATION PRECAUTIONS.
3. REQUIRED MINIMUM CLEARANCES to combustible material are as follows:
CLEARANCES/INSTALLATION
Outdoor Models
The minimum clearances from combustible material are as follows:
Control Side – Width of Unit
Opposite Control Side – 6 inches (18” recommended for servicing)
Top of Unit – Unobstructed
Discharge and Return Air Sides – 12 inches
Bottom – 0 inches
For installation downstream from refrigeration systems.
CLEARANCES/INSTALLATIION
Indoor Models
The minimum clearances from combustible material are as follows:
Control Side – Width of Unit
Opposite Control Side – 6 inches (18” recommended for servicing)
Top of Unit – 6 inches
Discharge and Return Air Sides – 12 inches
Bottom – 0 inches
For installation downstream from refrigeration systems.
* See section on ILLUSTRATIONS for dimensions of individual furnaces.
4. Install in airplane hangars in accordance with the current ANSI/NFPA 409 - “Latest Revisions”, Standard on Aircraft
Hangars, and in public garages in accordance with the current ANSI/NFFPA BB - “Latest Revisions”, Standards for
Garages, and with CANI-B149 Codes. A clearance of 10 feet must be provided from the bottom of the heater to the
top surface of wings or engine enclosures of the highest aircraft to be housed in the hangar and a minimum clearance
of 8 feet from the door in other sections such as offices and shops connected with hangar and in public garages.
Also, the heaters must be so located that they will be protected from damage by aircraft, cranes, scaffolding, etc., and
must be accessible for servicing and adjustment. Standard ANSI/NFPA 88 A, B - “Latest revisions” specifies that the
heater must be so located that the clearance to combustible materials conform with NFPA Nos. 52 and 54 and that
such material must not attain a temperature over 160º by continued operation of the heater.
5. If two furnaces are to be used in a side by side application, they must be installed so that the ENDS OPPOSITE the
control access doors ADJOIN.
6. A 4-inch frame is an integral part of the appliance and may be installed directly on the floor or roof or other
combustible construction. For ease of service and safe operation, however, it is suggested that the furnace be located
above the installation surface on a field fabricated base and should be high enough to prevent any form of moisture
from entering the unit.
7. Be sure that the roof joists or other obstructions will not interfere with the discharge and return air ducts.
8. The discharge and return air ducts should be correctly sized for securing to the furnace and all connections exposed
to the weather must be moisture tight. A high temperature caulking (250ºF) or sheet metal flashing may be used for
this purpose. A weathertight seal must be provided where ducts enter through the roof. Field installed ductwork on
the unit discharge end must be secured to the flanges on the heat exchanger and not on unit front cabinet.Failure to
properly install could cause fire, explosion, damage to equipment or even death.
9. Provide tight fitting inspection panels in duct work both upstream and downstream close to the furnace. These panels
must be large enough so that the heat exchanger can be easily inspected.
ELECTRICAL
1. Unit must be electrically grounded and all wiring must be done in accordance with applicable local codes and the
National Electrical Code, ANSI/NFPA 70, and/or the CSA C22.1 Canadian Electrical code, if an external electrical
source is utilized.
2. In order to determine the size of the power supply lines, check the electrical specification plate located on the
unit for ampere requirements.
3. On units not ordered with a disconnect switch, it is recommended that a weatherproof disconnect switch be
mounted on or near the unit.
4. Connect power supply lines from main disconnect switch to unit disconnect switch.
5. Install thermostat (RHF and RHV only) or remote control station if supplied according to wiring diagram.
6. Thermostats and remote control stations must be installed in a suitably protected and secure location to prelude
tampering and damage. Thermostats must not be exposed to physical shocks or jarring either before or after
installation.
9

VENTING
1. The (I) (IS) HRDV model furnace is equipped with a power venter and is complete as received.
2. No further venting of unit is required for outdoor installation (HRDV).
3. Indoor units (I) or (IS) are equipped with a blocked vent switch (VS-1) to shut off the main burners in the event the
vents are blocked sufficiently to prevent proper operation of the burners. The blocked vent switch is factory set and
should not be adjusted. If the blocked vent switch is determined to be the reason for the burners to shut off, consult
factory service agent for instructions before attempting to place furnace back into operation.
4. Venting is required on all indoor installations ISHRDV, and IHRDV units – See drawings “S-136” and “S-137” for
recommended arrangements.
a. Positive pressure flue vent is recommended for installations inside building. Provide for the ISHRDV and IHRDV
Series. For the requirement of positive pressure flue vent, review local codes.
b. Pitch vent pipe up toward outlet, ¼” per foot for condensate drainage.
c. Type “B” gas vent is recommended for flue venting above roof lines or external wall penetrations.
d. Straight vertical runs out through the roof are preferred. Vertical stack must be a minimum of five feet high.
e. Vertical flue stacks shall be terminated with an approved cap.
f. The maximum horizontal vent pipe length for these heaters is shown in table II. A total equivalent horizontal vent
pipe length can be calculated using equivalent straight pipe lengths for tees and elbows reducing the maximum
horizontal vent pipe length by six feet for each sweep elbow, two and one half feet for termination tee, and ten
feet for each short radius elbow.
g. Termination vents with screens require periodic cleaning to prevent the loss of proper venting, which can trip the
blocked vent switch.
h. A gradually tapered vent pipe transition is required for (I)ISHRDV-100, (I)ISHRDV-125, and (I)ISHRDV-160 units
when using 4 inch vent pipe.
i. When possible, locate horizontal vent hoods that do not face the direction of prevailing winds to diminish the
possibility of back draft situations.
j. For U.S.A. standards vent systems must conform to the latest edition of the National Fuel Gas Code
(NFPA#54) and the latest edition of NFPA #211, or as follows:
· Not less than 7 feet above grade when located adjacent to public walk ways.
· AT least 3 feet above any forced air inlet located within 10 feet.
· At least 4 feet below, 4 feet horizontally from or 1 foot above any door, window or gravity air inlet into
any building.
· At least 1 foot above grade, or at least 1 foot above the normally expected snow accumulation level.
· Directed such as to not jeopardize people.
· At least 4 feet from electric meters, gas meters, regulators and relief equipment.
· Sealing or shielding of exposed surfaces with a corrosion resistant material may be required to prevent
staining or deterioration of building materials, and
· Not less than 2 feet from an adjacent building.
k. In Canada vent systems must conform to the latest edition of the Natural gas and Propane Installation Code
(CAN/CGA-B149.1 or CAN/CGA-B149.2), or as follows:
· A venting system shall not terminate underneath a veranda, porch, or deck, or above a paved sidewalk
or a paved driveway that is located between two buildings, and that serves both buildings.
· The exit terminals of mechanical draft systems shall not be less than 2.14m above grade when located
adjacent to a paved sidewalk or driveway.
· A venting system shall not direct flue gases towards brickwork, siding, or other construction, in such a
manner that may cause damage from heat or condensate from the flue gases.
· A vent system shall not direct flue gases so as to jeopardize people, overheat combustible structures, or
enter buildings.
· A venting system shall not terminate within 1.8m of the following:
· A window, door or mechanical air supply inlet of any building, including soffit openings.
· A gas service regulator vent outlet.
· A combustion air inlet.
· A property line.
· A direction facing combustible materials or openings of surrounding buildings
· A venting system shall not terminate within 1m of the following:
· Above a gas meter/regulator assembly within 1m horizontally of the vertical centerline of the regulator.
· An oil tank or an oil tankfill inlet.
· The inside corner of an L-shaped structure.
· A venting system shall not terminate within .3m of the following:
· Above grade level or any surface that may support snow, ice, or debris.
10

1
3
7
"
VENTING"
INDOOR DUCT HEATER WITH SEPERATED COMBUSTION
OR INDOOR HEATING SYSTEM
P
ositive pressure vent flu
e
r
equired inside building
8
" Dia. Vent
P
ipe Type "B"
r
ecommended
1
1

1
4
"VENTING"
INDOOR DUCT HEATER
OR INDOOR HEATING SYSTEMS
8
" Dia. Vent
P
ipe Type "B"
r
ecommended
P
ositive pressure vent flu
e
r
equired inside building
7
1
2

TABLE II
I(S)HRDV HORIZONTAL FLUE SIZING
Unit Type Flue Pipe Diameter Maximum Length of Flue Pipe
I(S)HRDV-100 4.0 IN 82.0 FT
I(S)HRDV-125 4.0 IN 82.0 FT
I(S)HRDV-160 4.0 IN 82.0 FT
I(S)HRDV-210 6.0 IN 72.0 FT
I(S)HRDV-250 6.0 IN 72.0 FT
I(S)HRDV-300 6.0 IN 72.0 FT
I(S)HRDV-400 6.0 IN 72.0 FT
Gas Supply:
NOTE: PIPING MUST CONFORM TO STANDARDS OF THE NATIONAL BOARD OF FIRE UNDER-
WRITERS, CAN/CGA B149 AND ALL APPLICABLE GOVERNING CODES. INSTALL MANUAL MAIN
SHUT-OFF VALVE UPSTREAM OF APPLIANCE GAS TRAIN, OUTSIDE OF THE CONFINES OF THE
APPLIANCE IN ACCORDANCE WITH CURRENT INSTALLATON CODES.
1. Suggested pipe sizing for direct line from meter or propane tank is found in Table III. These sizes are based on 6” to 7”
w.c. pressure at the meter for natural gas; 11” w.c. for propane gas, with .3” w.c. pressure drop schedule 40 pipe and
fittings.
TABLE III
Input in 1000’s
BTU Hr.
Maximum Distance
from Meter Natural* Propane*
50 feet ¾” ½”
100 to125 100 feet 1” ¾”
60 feet 1” ¾”
150 to 175 100 feet 1 ¼” 1”
30 feet 1” ¾”
120 feet 1¼” 1”
200 to 250
250 feet 1½” 1¼”
75 feet 1¼” 1”
300 200 feet 1½” 1¼”
50 feet 1¼” 1”
400 to 420 100 feet 1½” 1¼”
35 feet 1 ¼” 1 ¼”
500 80 feet 1 ½” 1 ¼”
300 feet 2” 2”
50 feet 1½” 1¼”
600
200 feet 2” 2”
30 feet 1½” 1¼”
800 125 feet 2” 2”
80 feet 2 ” 2”
1000 200 feet 2½” 2”
50 feet 2 ” 2”
1200 150 feet 2½” 2¼”
30 feet 2 ” 2”
80 feet 2½” 2½”
1600
250 feet 3” 3”
The BTU input and output of these systems are listed in Table IV. See page 10.
*On units receiving inlet gas pressure in excess of 14” w.c., a high gas pressure regulator must be provided for each
heater section.
2. For larger installations or longer piping runs, consult gas company.
3. If more than ½ PSIG (14 in. W.C.) pressure is available, a high pressure regulator would be required. Pipe sizing may
be reduced. On heating systems with more than one duct furnace, multiple high gas pressure regulators may be
required.
4. Refer to items (3) and (4) of INSTALLATION PRECAUTIONS.
5. Pipe joint compound should be resistant to the action of L.P gas.
6. Install a DIRT TRAP (tee, nipple, and cap) at connection to each furnace.
7. For ease of servicing, an additional union and manual gas valve should be installed adjacent to the furnace exterior.
An approved, readily accessible manual gas valve should be joined to a ground joint type union immediately upstream
and connected to the appliance manifold piping.
13

8. A 1/8 N.P.T. plugged tapping, accessible for test gage connection, must be installed immediately upstream of the gas
supply connection to the appliance.
9. The furnace must NOT be operated without a leak limiting orifice installed in the unit pressure regulator vent, if
applicable.
10. The appliance and its individual shutoff valve must be disconnected from the gas supply piping system during any
pressure testing of that system at test pressures in excess of ½ PSIG.
11. The appliance must be isolated from the gas supply piping system by closing its individual manual shutoff valve during
any pressure testing of the gas supply piping system at test pressures equal to or less than ½ PSIG.
NOTE: CHECK ALL GAS CONNECTIONS FOR LEAKS. A SOAP SOLUTION SHOULD BE USED FOR THIS
PURPOSE. NEVER USE A TORCH OR FLAME OF ANY KIND.
TABLE IV
Unit BTU/Hr. Input
per Heater
Total BTU/Hr.
Input
Total BTU/Hr.*
Output
(IH) (ISH) (H) RHFA, RMUA, RHVA – 100 100,000 100,000 76,000 (80,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 125 125,000 125,000 95,000 (100,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 160 160,000 160,000 121,600 (128,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 210 210,000 210,000 159,600 (168,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 250 250,000 250,000 190,000 (200,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 300 300,000 300,000 228,000 (240,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 400 400,000 400,000 304,000 (320,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 600 300,000 600,000 456,000 (480,000)
(IH) (ISH) (H) RHFA, RMUA, RHVA – 800 400,000 800,000 608,000 (640,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 200 100,000 200,000 152,000 (160,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 250 125,000 250,000 190,000 (200,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 320 160,000 320,000 243,200 (296,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 420 210,000 420,000 319,200 (336.000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 500 250,000 500,000 380,000 (400,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 600 300,000 600,000 456,000 (480,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 800 400,000 800,000 608,000 (640,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 1000 250,000 1,000,000 760,000 (800,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 1200 300,000 1,200,000 912,000 (960,000)
(IH) (ISH) (H) RHFB, RMUB, RHVB – 1600 400,000 1,600,000 1,216,000 (1,280,000)
Honeywell Modusnap Valve
Model Size: 400
Temperature Settings of Controls
(Modusnap Valve, TL and DC)
(TL) SET THIS CONTROL TO 110 DEGREES, THERE IS NO OTHER SETTING ADJUSTMENT.
(This control is to protect the modusnap valve bulb from exceeding 120 degrees.)
(DC) SET THIS CONTROL TO 2 TO 3 DEGREES ABOVE MODUSNAP VALVE SETTING.
(MODUSNAP VALVE) SET THIS CONTROL 2 TO 3 DEGREES ABOVE ROOM THERMOSTAT SET POINT.
(This is to allow for temperature loss through duct work and room loss.)
MODUSNAP VALVE SETTINGS
Dial # 1 2 3 4 5 6 7 8 9
Degrees 60 65 70 75 80 85 90 95 100
(ROOM THERMOSTAT) SET AT ANY TEMPERATURE OCCUPANT WANTS, JUST SO LONG AS THE MODUSNAP
VALVE IS SET PROPERLY.
* All IH, ISH and H series units are 80% efficient
14

OPERATION
When the unit is in the winter mode, the fan is on bringing outside air into the building. The furnace is on and the
modusnap valve is set at 73 degrees (room set a 70 degrees – example), the modusnap valve is modulating at this point
maintaining the discharge of 73 degrees. When the room thermostat calls for more heat, the bypass valve opens and full
rate of gas is supplied to burner for full heat until the room thermostat is satisfied. (NOTE: In the event the discharge
temperature gets up to 110 degrees, the “TL” will cycle the bypass valve during the room override mode.) When the room
thermostat is satisfied, the furnace will return to discharge temperature of 73 degrees when the heat exchanger cools
down from the high fire condition.
The 400 Model has an additional bypass without any valve control. This is called a minimum rate tube (M.R.T.). During
mild weather, the Modusnap valve will cycle on minimum flow while the M.R.T. is flowing gas. For its control the “DC” will
cycle the main shut off valves to maintain discharge temperature. (There is no gas flow to burner when “DC” is satisfied
unless the unit has a room override option on the “DC” circuit.)
ALL MODEL SIZES SMALLER THAN THE 400
OPERATION:
Settings are the same as above except less the M.R.T. and “DC” control.
VALVE ADJUSTMENTS
(See bulletin MT2035 for additional M/MR valve information)
Note: High Fire Adjustment should be checked whenever Low Fire Adjustment is changed.
Disconnect wire from amplifier terminal 3, remove cover plate (2).
15
High Fire Adjustments:
(A) Using the maximum adjustment screw (4), set
manifold pressure to furnace manufacturer’s
specifications.
(B) Replace cover plate (2) on Modulator-Reg-
ulator valve and reconnect wire to amplifier
terminal 3.
.
Low Fire Adjustments:
(A) Remove maximum adjusting screw (4),
spring (5), and plunger (8). A small magnet
is useful for this purpose.
CAUTION: The plunberis a precision part.
Handle carefully to avoid marring or picking
up grease and dirt. Do not lubricate.
(B) Using minimum adjusting screw (9), set
manifold pressure to furnace manufacturer’s
specifications.
(C) Replace plunger and spring retainer, spring,
and maximum adjusting screw in proper
order.
1. TOP HOUSING
2. COVER PLATE
3. SEAL GASKET
4. MAXIIUM ADJUSTMENT SCREW
5. MAXIMUM ADJUSTMENT SPRING
6. SOLENOID
7. MINIMUM ADJUSTMENT SPRING
8. PLUNGER
9. MINIMUM ADJUSTMENT SCREW
10. MINIMUM ADJUSTMENT SCREW STOP

ELECTRONIC IGNITION:
All (I) (IS) HRDV series furnaces are equipped with a solid state design, intermittent pilot ignition system. This electronic
system consists of an ignition control module, combination pilot burner/igniter-sensor (sensor or flame rod) assembly, and
igniter-sensor lead. Activated by the units 24V transformer and controlled by a field installed thermostat or controller,
module will first perform a safe-start check which tests its internal components for a false pilot flame condition. If
satisfactory, the module then energizes the pilot gas valve to open and generates 15,000 V peak capacitive discharge
ignition spark to ignite pilot burner. When pilot is established, the flame monitoring circuit of module responds to the
presence of flame detected by the flame rod and discontinues ignition spark. The main gas valve is then energized to
open, pilot lights main burners, and burner operation continues until call for heat is satisfied. Module then deactivates both
pilot and main gas valves and unit shuts down.
Two types of ignition control modules are utilized. A non 100% shutoff design is used with natural gas ONLY. It provides
continuous spark for pilot ignition, but if pilot does not light, trouble must be isolated and corrected. A 100% shutoff design
may be used for natural and L.P. gas. It provides a 90 second gas trial for pilot ignition. If pilot does not light within the trial
time, module deactivates pilot valve (100% safety lockout) but continues spark for pilot ignition. This system may be reset
at the thermostat or controller and trial for ignition resumed. If pilot still fails to ignite, trouble must be isolated and
corrected.
Preliminary Circuit Analysis
In order to diagnose the cause of problems in this
system, it is necessary to determine certain values. It is
helpful to have an AC and DC voltmeter and an
ohmmeter capable of reading 0 to 15,000 ohms. For
ease in troubleshooting, it is necessary to rewire the
system, replacing the discharge air sensor with a 4500
ohm, ½ watt test resistor.
Modulating Function Test:
Connect a DC voltmeter to amplifier terminals 1 and 2. If
more convenient, the meter may be attached to the MR
valve terminals. Rotate temperature selection knob to
maximum setting – the DC volts should read zero. The
voltage should gradually increase to at least 20 volts
when the temperature selector is slowly rotated to its
minimum (generally over a 3º to 4º range).
Automatic Valve Function:
After the electronic modulation function is tested, a
voltage reading must be taken across the automatic gas
valve. These voltage readings will be approximately 24 V
AC with the temperature selection knob at maximum
setting, zero volts AC with the selector at minimum
setting. The relay switching action should occur when
the modulating voltage is between 15 and 19V DC.
If these voltage readings are observed as noted, it is
proved that the amplifier and temperature selector are
operating properly.
After testing, remove the resistor and reconnect the
discharge air sensor.
Maintenance
CLEANING:
NOTE: SOOT, DIRT, ETC. WILL PREVENT PROPER COMBUSTION. FOR NORMAL AIR CONDTIONS, CLEAN
UNIT PRIOR TO HEATING SEASON WITH A PERIODIC INSPECTION AT LEAST ONCE A MONTH
THROUGHOUT THE DURATION OF THE SEASON AND CLEAN AS NECESSARY. IN HEAVILY
CONTAMINATED AREAS, INSPECTION AND POSSIBLE CLEANING MAY BE REQUIRED MORE FREQUENT-
LY DURING THE HEATING SEASON. CLEAN FLUE TUBES, BURNERS AND PILOT BEFORE THEY
BECOME BADLY FOULED.
·Cleaning Flues:
1. Outdoor units:
a. Remove burner drawer assembly. To accomplish, close manual gas valve to unit and break main gas supply at
union. Cut furnace electrical supply. Unscrew the two quick fasteners at the bottom of the control access panel.
Pull bottom of panel away slightly and allow panel to drop. Remove panel and disconnect applicable electric
wiring. Remove retaining “L” tab at the end of the burner drawer and slide drawer assembly out of the furnace.
b. Remove the screws holding top panel and lift panel off.
c. Remove the screws from bottom flange of the collector box cover and lift cover off.
16

d. Remove the screws from bottom flange of the collector box. Remove the two screws from the venter motor
support at the right heater leg and disconnect the three conductor cables at the junction box. Lift collector box off.
(Power venter assembly will remain attached to the collector box.)
e. Lift flue baffles from tubes.
f. Clean the inner surfaces of flue tubes using a 1-1/2” or 1-3/4” long-handled wire brush. Clean and replace flue
baffles.
g. Remove dirt from bottom pan and clean burners before replacing drawer assembly. (Be sure to reinstall “L” tab
after drawer assembly is installed in the heater.)
1. Indoor Units:
a. Disconnect exhaust flue from unit flange.
b. Disconnect separated combustion air flue from unit flange (ISHRDV models only).
c. Remove the (4) screws holding the top portion of the burner control vestibule door around the power venter outlet.
d. Remove burner control vestibule door by turning bottom latches on door.
e. Pull the door away by pulling the bottom rail on the door outward.
f. On some models a (2) piece door is provided. (2) screws hold the top portion of the door in place. Remove
screws and remove top door portion.
g. Remove burner drawer assembly. To accomplish, close manual gas valve to unit and break main gas supply at
union. Cut furnace electrical supply. Unscrew the two quick fasteners at the bottom of the control access panel.
Pull bottom of panel away slightly and allow panel to drop. Remove panel and disconnect applicable electric
wiring. Remove retaining tabs at each end of the burner drawer and slide drawer assembly out of the furnace.
h. Remove the screws holding top panel and lift panel off.
i. Remove the screws from bottom flange of the collector box cover and lift cover off.
j. Remove the screws from bottom flange of the collector box. Remove the two screws from the venter motor
support at the right heater leg and disconnect the three conductor cables at the junction box. Lift collector box off.
(Power venter assembly will remain attached to the collector box.)
k. Lift flue baffles from tubes
l. Clean the inner surfaces of flue tubes using a 1-1/2” or 1-3/4” long-handled wire brush. Clean and replace flue
baffles.
m. Remove dirt from bottom pan and clean burners before replacing drawer assembly. (Be sure to reinstall “L” tab
after drawer assembly is installed in the heater.)
·Cleaning Burners:
1. Burners can be removed from drawer assembly by raising front of burner, pushing burner forward against the
hold-down clip until venturi end of burner is free of support. Remove burners next to pilot last and replace these
burners first.
2. Remove ribbon cotter pin and carefully pry ribbon from slot.
3. Clean ribbon with brush and blow off dust.
4. Replace ribbon and cotter pin.
5. Replace burners, making certain that they seat properly in place.
6. Failure to re-seat burner assemblies properly could result in fire, explosion, equipment damage or death.
·Cleaning Pilot:
1. Disconnect tubing from pilot body, remove igniter lead and detach pilot burner assembly from support.
2. Remove pilot orifice fitting.
3. Using a small brush, clean pilot burner assembly, orifice, and flame rod. Blow off loose particles.
4. Assemble and install in original position.
5. Adjust pilot flame to surround flame rod tip about 3/8”. Flame must be soft – not hard, noisy, or yellow.
17

·Additional Maintenance Procedures:
1. Motors should be relubricated according to the manufacturer’s lubrication instructions.
2. Filters must be cleaned (cleanable type) or replaced (throw-away type) with like filters as often as necessary so as not
to restrict air delivery.
3. Twice a year check belts and sheaves for alignment and belt tension.
4. When a belt is replaced, shorten center distance between sheaves by loosening motor bolts and sliding motor on
support. On units requiring multiple belts, use a matched set.
5. The following procedure is recommended for tensioning belts:
A. Measure span length “X” shown in Figure I.
B. At the center of span length “X”, apply a force perpendicular to the span and large enough to deflect belt 1/64” for
each inch of span length.
Example – The required deflection for a 40” span would be 40/64” or 5/8”.
C. Compare the force applied with the values given in Table V. If force is between the minimum and maximum
range shown, the drive tension should be satisfactory. A force below the minimum value indicates an
undertensioned belt and a force that exceeds the maximum value indicates an overtensioned belt.
6. Lubricate main fan bearing with a high grade lithium base grease. Perform at least every quarter (three months)
or schedule according to equipment use.
TABLE V
Deflection Force
Belt Cross Section
(marked on belt) Motor Pulley Pitch Diameter Minimum Maximum
3.0” – 3.6” 2.62 lbs. 3.25 lbs.
3.8” – 4..8” 3 lbs. 4 lbs.
A
5.0”- 7.0” 3.25 lbs. 5 lbs.
3.4” – 4.2” 3 lbs. 5 lbs.
4.4” – 5.6” 4 lbs. 5.87 lbs.
B
5.8” – 8.6” 5.25 lbs. 7.87 lbs.
FIGURE I
LUBRICATION INSTRUCTIONS FOR MOTORS
Some small motors have sealed-for-life bearings which require no relubrication. Regreasable bearings are shipped with a
high quality, wide temperature range grease in the bearings.
Motors can be regreased by stopping the motor, removing drain plug and pumping new grease into fill hole. Run motor
with drain plug removed until excess grease has been discharged (minimum 10 min.). Stop motor and replace drain plug.
Units that operate at speeds greater than 1800 RPM should be lubricated on a more frequent maintenance schedule
depending on duty cycle. Use a low pressure grease gun and avoid overgreasing.
18