
Optional Equipment
Dimensions
Nomenclature
Equipment
Minimum Clearance to
Combustible Construction
Humidifier (HUM)
Electronic Air Cleaner (EAC)
UV Lamp
Cooling Coil
Warranty
* In order to receive full warranty coverage on the Hyrdronic Furnace when connected to any other type or
brand of product other than a Rinnai tankless water heater, the flow rate through the Hydronic Furnace
must not exceed a maximum of 5 GPM.
Rinnai will repair or replace the covered product or any part or component that is defective in materials or
workmanship as set forth.
Rinnai will pay reasonable labor charges associated with the repair or replacement of any such part or
component.
All repair parts must be genuine Rinnai parts. All repairs or replacements must be performed by an
individual or servicing company that is properly trained, state qualified or licensed to do the type of repair.
Parts: 5 years * / Labor: 1 year *
CABINET
20 gauge
prepainted
galvanized steel
fully insulated
HEAT
EXCHANGER
copper tube
aluminum fin
PUMP
high-head
low-flow
integrated check valve
BLOWER
ASSEMBLY
multi-speed motor (ECM)
Connect an auxiliary 2.5 FLA, 2.5 LRA @ 115 VAC max Humidifier.
Connections are made via the “HUM” quick connects. The humidifier
output is on whenever a heating demand is being satisfied. The
contacts of this output are isolated to allow application of 24 VAC or
115 VAC to one terminal and the humidifier load to the other.
Connect an auxiliary Electronic Air Cleaner; rating shall be max 1.0
Amp @ 115 VAC. This output is energized whenever any of the four
blower speeds are energized. Connections are made via 0.250 x
0.032” male quick connect terminals labeled "EAC" and "N3".
Connect an auxiliary UV lamp (if required); rating shall be max 1.0
Amp @ 115 VAC. This output is energized whenever any of the four
blower speeds are energized. Connections are made via 0.250 x
0.032” male quick connect terminals labeled "UV" and "N2".
Can accomodate most brands of evaporator A-coil for cooling
applications.
FIELD-SUPPLIED ACCESSORIES
capable of interfacing with the Rinnai Hydronic Furnace:
37AHB Series Hydronic Furnace
37AHB Series Hydronic Furnace
37AHB Series Hydronic Furnace
Accessories
Heating Capacities
THERMOSTATS
Programmable, 5-2 days;
both A/C and heat pump
versions
FLOW SENSOR *
For domestic hot water priority
* Supplied with the unit
ANTI-SCALD MIXING
VALVE
To maintain safe domestic
hot water temperature
FILTER RACK
and BOTTOM FILL PLATES
For modification to allow side-entry
return airflow
Factory available from Rinnai
CONTROL
BOARD
integrated
microprocessor based
FILTER
37AH B 045 08 K A 5
Multi-position
5 = Yes
2 = No
Engineering Digit
Denotes minor change
Voltage Code (V-Ph-HZ)
K = 115 - 1 - 60
L = 240 - 1 - 50 (export models)
Model
37AH - Multi-speed Hydronic Furnace
Series
A - Unit with PSC Motor
B - Unit with ECM Technology
Nominal Heating Capacity (BTU/h)
045 = 45,000
060 = 60,000
075 = 75,000
090 = 90,000
Cooling / Heating
Air Flow Range (CFM)
08 = 800 (650-800)
12 = 1200 (650-1200)
14 = 1400 (1000-1600)
16 = 1600 (1200-1750)
6"
17 13/16"
1"
18 5/16"
1"
C
B
34"
A
22"
E
1 3/8"
D
17 13/16"
2 1/8"
TOP/PLENUM
zero
SIDE
zero
BACK
zero
SIDE
zero
FRONT
zero
BOTTOM
zero
SERVICING
24” (610 mm)
Nominal heating capacities as tested with Rinnai tankless water heaters.
For final rated capacities refer to the Air Delivery and Performance
Tables in the Operation and Installation Manual.
AHB45 (BTU)
AHB60 (BTU)
AHB75 (BTU)
AHB90 (BTU)
120º F
27,700
36,400
43,700
54,900
130º F
33,300
45,100
52,900
63,900
140º F
40,100
50,800
61,600
76,200
150º F
47,700
59,700
70,400
86,600
160º F
51,200
68,100
78,900
96,300
in.
mm
in.
mm
in.
mm
in.
mm
in.
mm
37AHB04508KA5 (AHB45)
14
355.6
18
457.2
12
304.8
10 - 1/2
266.7
19
482.6
37AHB06012KA5 (AHB60)
17 -1/2
444.5
18
457.2
16
406.4
16 - 11/16
423.9
19 - 1/4
489
37AHB07514KA5 (AHB75)
21
533.4
18
457.2
20
508
18 - 11/16
474.7
19 - 1/2
495.3
37AHB09016KA5 (AHB90)
24 - 1/2
622.3
18
457.2
24
609.6
21 - 1/8
536.6
19
482.6
UNIT SIZE
A
B
C
D
E
C
M
Y
CM
MY
CY
CMY
K
37AHB spec sheet inside (7-2010).ai 7/23/2010 11:58:33 AM
37AHB spec sheet inside (7-2010).ai 7/23/2010 11:58:33 AM