Operating instructions

21
PROBLEM
POSSIBLE CAUSE
CHECKS AND CORRECTIONS
Remote Hydronic Control or
Room Thermostat
Improperly located thermostat (e.g. near kitchen, sensing inaccurately the comfort
level in living areas).If thermostat has an anticipator, it should be set at 1.0 or 1.2.
Unit short cycles
Compressor Overload
Defective compressor overload, check and replace if necessary. If the compressor
runs too hot, it may be due to a insufficient refrigerant charge.
Aquastat
The differential is set to close on Aquastat. Increase differential setting to 15
o
F.
Wiring and Controls
Loose wiring connections, or control contactor defective.
Thermostat Improperly Set
Is it below room temperature? Check the thermostat setting.
Unit will not
Defective Thermostat
Check thermostat operation. Replace if found defective.
operate in
Incorrect Wiring
Check for broken, loose, or incorrect wires.
"heating"
Aquastat set Too High
Heat pump is trying to heat hot water to too hot of a temperature (over 120
o
F).
Reduce Aquastat setpoint.
Remote Hydronic Control or
Room Thermostat
Ensure that these products are properly configured according to their own
instructions for the “System Type” they are installed on.
Reversing Valve does not Shift
Defective solenoid valve will not energize. Replace solenoid coil.
Unit does not cool
(Heats Only)
Reversing Valve does not Shift,
the Valve is Stuck
The solenoid valve is de-energized due to miswiring at the unit or remote control -
correct wiring. Replace if valve is tight or frozen and will not move. Switch from
heating to cooling a few times to loosen valve.
Aquastat set Too Low
Heat pump is trying to cool water too low. Increase Aquastat setpoint.
Insufficient Antifreeze
Water is freezing in hydronic coil. Check antifreeze level and add antifreeze to obtain
correct freeze protection.
Noisy Operation
Compressor
Make sure the compressor is not in direct contact with the base or sides of the
cabinet. Cold surroundings can cause liquid slugging, increase ambient temperature.
Contactor
A "clattering" or "humming" noise in the contactor could be due to control voltage
less than 18 volts. Check for low supply voltage, low transformer output or extra long
runs of thermostat wires. If the contactor contacts are pitted or corroded or coil is
defective, repair or replace.
Rattles and Vibrations
Check for loose screws, panels, or internal components. Tighten and secure. Copper
piping could be hitting the metal surfaces. Carefully readjust by bending slightly.
Check that hard plumbing is isolated from building structures.
Water and Airborne Noises
Excessive water through the water-cooled heat exchanger will cause a squealing
sound. Check the water flow ensuring adequate flow for good operation but
eliminating the noise.
Cavitating Pumps
Purge air from ground loop or hydronic loop system.
Squealing Sound from Inside the
Cabinet
Purge air from the water side of the desuperheater heat exchanger or defective
desuperheater heat exchanger.