Water Furnace 502W12, Installation Manual

Page: 29 / 32

29
5 SERIES 502W12 INSTALLATION MANUAL
Should a major problem develop, refer to the following
information for possible causes and corrective steps.
If compressor won’t run:
1. The fuse may be open or the circuit breaker is tripped.
Check electrical circuits and motor windings for shorts
or grounds. Investigate for possible overloading. Replace
fuse or reset circuit breakers after fault is corrected.
2. Supply voltage may be too low. Check it with a
volt meter.
3. Control system may be faulty. Check control for correct
wiring of thermostat or aquastat and check the 24 volt
transformer for proper voltage.
4. Wires may be loose or broken. Replace or tighten.
5. The low pressure switch may have tripped due to one
or more of the following:
a) Heating
1) Plugged heat exchanger on source side
2) Water flow source side - (Low)
3) Water too cold source side
4) Low refrigerant
b) Cooling
1) Plugged heat exchanger on load side
2) Water flow load side - (Low)
3) Water too cold load side
4) Low refrigerant
6. The high pressure switch may have tripped due to one
or more of the following:
a) Heating
1) Plugged heat exchanger on load side
2) Low water flow load side
3) Water too warm load side
b) Cooling
1) Plugged heat exchanger on source side
2) Low water flow on source side
3) Water too warm source side
7. The compressor overload protection may be open.
Troubleshooting
8. The internal winding of the compressor motor may
be grounded to the compressor shell. If so, replace
the compressor.
9. The compressor winding may be open or shorted.
Disconnect power. Check continuity with ohm meter. If
the winding is open, replace the compressor.
If sufficient cooling or heating is not obtained:
1. Check control for improper location or setting.
2. Check for restriction in water flow.
3. Check refrigerant subcooling and superheat for proper
refrigerant charge and expansion valve operation.
4. The reversing valve may be defective and creating a
bypass of refrigerant. If the unit will not heat, check the
reversing valve coil.
If the unit operation is noisy:
1. Check compressor for loosened mounting bolts. Make
sure compressor is floating free on its isolator mounts.
Check for tubing contact with the compressor or other
surfaces. Readjust it by bending slightly.
2. Check screws on all panels.
3. Check for chattering or humming in the contactor or
relays due to low voltage or a defective holding coil.
Replace the component.
4. Check for proper installation of vibration absorbing
material under the unit.
5. Check for abnormally high discharge pressures.
6. Compressor rotation incorrect
Unit Heat Exchanger Maintenance
1. Keep all air out of the water or antifreeze solution.
2. Keep the system under pressure at all times. Closed
loop systems must have positive static pressure or air
vents may draw air into the system.
NOTES: If the installation is in an area with a known high
mineral content in the water, it is best to establish with
the owner a periodic maintenance schedule for checking
the water-to-refrigerant heat exchanger on a regular
basis. Should periodic cleaning be necessary, use standard
cleaning procedures. Generally, the more water flowing
through the unit, the less chance there is for scaling. Low
gpm flow rates produce higher temperatures through the
heat exchanger. To avoid excessive pressure drop and the
possibility of metal erosion, do not exceed gpm flow rate as
shown on the specification sheets for each unit.
Preventive Maintenance
Replacement Procedures
When contacting the company for service or replacement
parts, refer to the model number and serial number of the
unit as stamped on the serial plate attached to the unit.
If replacement parts are required, mention the date of
installation of the unit and the date of failure, along with an
explanation of the malfunctions and a description of the
replacement parts required.
In-Warranty Material Return
Material may not be returned except by permission
of authorized warranty personnel. Contact your local
distributor for warranty return authorization and assistance.