6
16
33
1
/
4
22
1
/
8
12
1
/
2
5
18
3
1
/
4
2
THERMOSTAT CONN
(ELECTRICAL CONN
ON OTHER SIDE)
GAS
CONN
3/4 NPT PIPE
TO DRAIN
26
1
/
4
1
/
2
C
11
7
/
8
6
INLET
OUTLET
3
1
/
8
MIN
19
K
AUTOMATIC
VENT DAMPER
(FIELD INSTALLED)
B
A
Fig. 1: Dimensions
Model
No.
Input
MBH
Heating
Capacity
M
BH
Net
I=B=R
R
ating
Piping Connections
A B C
K
Vent
D
ia.
Water
NPT
Gas NPT
H
-0042
4
2
3
5
3
0
1
in.
1
/2 in.
1
1 in.
5
3/4 in.
5
1/2 in.
4
in.
H-0066 66 54 47 1 in. 1/2 in. 11 in. 5 3/4 in. 5 3/4 in. 5 in.
H-0090 90 74 64 1 in. 1/2 in. 11 in. 5 3/4 in. 5 3/4 in. 5 in.
H-0135 135 109 95 1 1/4 in. 1/2 in. 18 in. 6 1/4 in. 6 1/4 in. 6 in.
H-0180 180 148 129 1 1/4 in. 1/2 in. 18 in. 6 1/4 in. 8 in. 7 in.
Table A: Specifications