IO-123090-GFW-020113
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©2013 AirMark
7) Air filter replacement: An air filter can restrict
the airflow of air to the fan coil if it is not
cleaned or replaced periodically. When
replacing the air filter, always replace with the
same type and size as originally furnished with
the unit.
GFW Hydronic Related General
Information
1) Equipment Sizing
Select an air handler with a heating output that
exceeds the space heating loss of the structure
and that has a cooling coil sized to match the
outdoor condensing unit.
Note:
The heating output of the air handler or hot
water coil will not be greater than the output of the
selected hot water heater. Therefore, if the water
heater is undersized the heating BTUH of the air
handler will be LESS than its rated output.
2) Water Heater Selection
The following sizing information should only be
used as a basic guide to adequate water heater
sizing because of variations in each family's
domestic hot water requirements. For additional
assistance in water heater sizing contact a
professional engineer.
Proper water heater sizing should consider both
the gallon capacity
AND
the BTU input of the water
heater.
a.
To determine water heater GALLON
CAPACITY: A minimum 40-gallon high recovery
and/or high efficiency gas or oil-fired water heater
is recommended. The following volume-sizing
guide is satisfactory in most areas of the country:
CFM
Min Water Heater
600-800 40
gal
1000-1200 50
gal
1400-1600
2x40 gallons piped together
High input 50 gallons (63-75k Btu)
72-75gallons
2000 105k
Btu
b.
To determine water heater BTU INPUT
(assumes a water heater recovery efficiency of
76%): For mild climates: BTU INPUT=structure’s
heat loss x 1.51. For colder climates: BTU
INPUT=structure's heat loss x 1.58.
3) Pump Replacement
a.
Disconnect electrical power to the unit before
servicing.
b.
Remove access door to reveal pump. Close
supply valve ("A") and return valve ("B"). Open the
air bleed valve to de-pressurize the system and
drain water.
c.
Remove the metal pump housing by loosening
the four screws on the pump. DO NOT UN-
SOLDER PUMP.
d.
Replace the new pump housing assembly and
reconnect components to the pump. Before
assembling, make sure that the runner on the o-
ring is in place on the pump housing.
e.
Purge the system of the air as described earlier
and re-connect the electrical power.
Common Problems and Solutions
1) Noisy Pump
System may not be totally purged of air. Purge the
system again as described in the start up section
above.
2) T&P valve on water heater weeps
This normally occurs when a backflow preventer
has been installed in the cold water supply line to
the water heater. An expansion tank may be
necessary to correct this problem. Please contact a
qualified plumbing professional for assistance.
3) Hot water is circulating through the water
coil during cooling cycle
The check valve may be stuck open and allowing
hot water to circulate through the coil.
4) Little or no heat from water coil
a. Purge the system
b. The inlet connections may be reversed at the
fan coil
c. Water heater thermostat is not set at proper
temp
d. Water heater thermostat is not calibrated
e. Dip tube in the water heater may not be installed
correctly or could be restricted.
f. Look for restrictions in heating system from water
heater to fan coil. Some water heaters are supplier
