-3-
If a steel hydropneumatic tank is in place, replace it with a properly sized diaphragm
expansion tank. Otherwise, significant heat transfer problems can occur by causing air to
be trapped in the heat exchanger. If the boiler system has an existing expansion tank and the boiler temperatures
are being changed, resize the existing diaphragm expansion tank.
Use care when using a torch near the top cover and heat exchanger plate. It is recommended
that the front half be removed prior to soldering to avoid potential damage.
3. Required Components And
Accessories Checklist
Boiler Return
Cold Water
Inlet
Retaining Screws (2)
Heat Trap
Boiler Supply
Hot Water
Outlet
15
10
5
0
0
2
4
6
8
Head Loss (Feet)
Flow (Gallons Per Minute)
HYDROMAX
®
Components
(Single Wall Shown)
Two-Piece Cover Removal and Installation
Heat Exchanger Pressure Loss
MODEL
CIRCULATOR
PERFORMANCE ZONE VALVE
SHUTOFF
VALVES
RELIEF VALVE
THERMAL
EXPANSION
TANK
HM-41
4 GPM @ 6 FT
3/4" Full Port
4
Included
2.0 Gallon
HM-80
4 GPM @ 6 FT
3/4" Full Port
4
Included
4.4 Gallon
Removing Front Half:
Depress both tab buttons to
detach one side at a time.
Installing Front Half:
Align bottom groove of cover
onto metal retaining ring.
Beginning with one side,
align pin and push until both
tabs lock. Repeat for other
side, ensuring all tabs are
fully engaged.
Removing Entire Cover:
Remove front half, loosen
both retaining screws and
remove rear half.
Tab Buttons (4)
