Mueller Model D Fre-Heater Installation and Operation Manual
Effective March 1, 1993
Part No. 8800430
Revised November 6, 2019
2.4 INSTALLING WATER PIPING
The Model “D” Fre-Heater is equipped with
3
⁄
4
" or 1
1
⁄
2
" connections for the cold water inlet and the hot water outlet,
depending on the specific model (refer to Table 1).
The water inlet connection is labeled “COLD” and the outlet connection is labeled “HOT.”
The pipe from the “HOT” outlet should go to the conventional water heating system, if one is being used. Please see
Figures 5 and 6.
FIGURE 5: TYPICAL HOT WATER DUMP VALVE PIPING
FIGURE 6: TYPICAL PLUMBING FOR FRE-HEATER WATER CONNECTION
6
Hot
Water
Outlet
Cold Water Inlet
Check
Valve
Water Dump Valve
N.O.
N.O.
N.C.
Mueller®
Fre-Heater®
Model
ERS 120-E
Only
Mueller
Fre-Heater
Hot
Water
Outlet
Cold
Water
Inlet
N.O.
N.C.
N.O.
Pressure
Temperature
Relief Valve
Drain
Hot Water Out
From Fre-Heater
(Optional)
Hot Water
In From
Fre-Heater
Conventional
Water
Heater
Hot
Water
Outlet
Pressure
Temperature
Relief Valve