First Co EVBQ (Variable Speed) - Manual (Page 7)

CAUTION: An expansion tank may be required if a back-flow preventer is installed in the system. Failure to
follow this CAUTION could result in product and property damage.
Hot Water Coil Piping
Hot water coil connections are 3/4 inch nominal (7/8” OD) copper.
The hot water supply to the fan coil will be on the right when facing the fan coil upright and from the front.
All piping between the water heater and fan coil unit should be copper and should not exceed 200 feet of total piping. It is
recommended that 3/4” nominal (7/8” OD) piping should be used on 18 to 48EVBQ units to prevent excessive head pressure
losses. (Consult the factory for other piping applications.)
CAUTION: When connecting piping to fan coil units, do not bend or reposition the coil header tubing for
alignment purposes. This could cause a tubing fracture resulting in a water leak when water pressure is
applied to the system. Failure to follow this CAUTION could result in personal injury or product and property
damage.
Hot water coil sweat connections:
1. Review hot water coil piping precautions.
2. Insert water lines into hot water coil headers.
3. Solder copper joints with low temperature - non lead solder.
4. When all connections are complete, pressure test the system with water. Repair any solder joint leaks and gently
tighten any leaking valve packing nuts and piping accessories as required.
It is also recommended that all piping be adequately insulated to prevent freezing when piping is run in an unconditioned space.
Failure to follow this could result in product and property damage due to frozen water line breakage.
CAUTION: Hydronic systems are not designed to hold pressurized air and should only be tested with water.
Failure to follow this CAUTION could result in personal injury or product and property damage.
Figure 4 - Piping Connections
HOT
WATER
HEATER
WATER SUPPLY
TO HEATER
3
HOT WATER
SUPPLY TO
HOUSE
2
HOT WATER COIL
FLOW
FLOW
BLEED
VALVE
FLOW CONTROL
MODULE
1
FLOW
1) FLOW CONTROL MODULE
CONSIST OF: PUMP, CHECK
VALVE AND BLEED VALVE
2) ISOLATION VALVE: SUPPLY LINE
3) ISOLATION VALVE: RETURN LINE
7