First Co UC-HW (without installed pump) User Manual
Page 5
CHECK VALVE
REPLACEMENT
Disconnect electrical power before
servicing the unit.
To replace the internal check valve,
close the isolation valves and relieve the
water pressure within the heating
loop.
Remove the four hex head screws secur-
ing the pump motor to the pump's volute
and remove. The check valve is located
in the volute.
Rotate the check valve to release and
remove from the volute.
HOT WATER COIL
2
3
HOT WATER
SUPPLY TO
HOUSE
HOT
WATER
HEATER
FLOW
FLOW
WATER SUPPLY
TO HEATER
FLOW CONTROL MODULE
CONSIST OF: PUMP, CHECK
VALVE AND BLEED VALVE
BLEED
VALVE
1)
ISOLATION VALVE: SUPPLY LINE
2)
ISOLATION VALVE: RETURN LINE
3)
FLOW
1
FLOW CONTROL
MODULE
TYPICAL PIPING SCHEMATIC
Figure 4
w / Flow Control Module
**MAINTENANCE UPDATES**
For a current copy of the
Maintenance Program log
on to www.fi rstco.com and
look under "Product Informa-
tion"
Reverse the above steps for reinstall-
ing a check valve, however make sure
that the pump or volute has the rubber
o-ring in place before assembling.