Page 17
Model
(Size)
20°F
25°F
30°F
35°F
flow
gpm
H/L
feet
flow
gpm
H/L
feet
flow
gpm
H/L
feet
flow
gpm
H/L
feet
200
17
1.6
14
1.0
11
0.7
10
0.5
300
26
3.5
20
2.3
17
1.6
15
1.2
400
34
6.3
27
4.0
23
2.8
19
2.1
Metric Equivalent
Model
(Size)
11°C
14°C
17°C
19°C
flow
lpm
H/L
m
flow
lpm
H/L
m
flow
lpm
H/L
m
flow
lpm
H/L
m
200
64
0.5
51
0.3
43
0.2
37
0.2
300
97
1.1
77
0.7
64
0.5
55
0.4
400
129
1.9
103
1.2
86
0.9
74
0.6
Notes:
gpm = gallons per minute, lpm = liters per minute,
H/L = head loss, ft = head loss in feet,
m = head loss in meters.
Maximum temperature rise is 35°F (19°C), as shown.
Head loss is for boiler’s heat exchanger only.
N/R = not recommended.
Table 8. Water Flow Requirements - MT2H.
Figure 5. Hydronic Piping — Multiple Boilers, Primary Secondary System.
4.B Water Connections — Water Heater
4.B.1 Water System Piping — Water Heater
Hot water piping should be supported by suitable
hangers or floor stands. Do not support piping with
this appliance. Due to expansion and contraction of
copper pipe, consideration should be given to the type
of hangers used. Rigid hangers may transmit noise
through the system resulting from the piping sliding in
the hangers. It is recommended that padding be used
when rigid hangers are installed.
This appliance can be used with several different
types of readily available storage tanks. A pump draws
water from the storage tank and pumps the water
through the heater and back into the tank. Pump-
mounted units have a circulating pump built into the
water heater. The pumps used are sized for the head
loss through the heater, plus 30 feet (9.1 m) of full-
sized piping (same size as boiler outlet) and a normal
number of fittings. Pumps used on pump-mounted unit
are sized for soft/normal or hard water, so make sure
a pump-mounted unit matches the water quality of the
installation.
Pipe the outlet from the heater’s relief valve
such that any discharge from the relief valve will be
conducted to a suitable place for disposal when relief
occurs. Do not reduce line size or install any valves in
this line. The line must be installed to allow complete
drainage of both the valve and the line.
Suggested piping diagrams are shown as
Figure 5,
Figure 6, Figure 7, and Figure 8
, and Figure 9. These
diagrams are meant only as a guide. Components
required by local codes must be properly installed.
The minimum inlet water temperature for this
appliance is 130°F (54°C) to avoid condensing on the
copper coils.
Mighty Therm
2
(200, 300, 400) Install & Operating