User guide

16
MAMM-WSHP-IOM-1KA (September 2011)
Performance Troubleshooting
Performance
Troubleshooting
Heating Cooling Possible Cause Solution
Unit doesn’t operate in cooling X X Low refrigerant charge Check superheat and subcooling
X X
Restricted metering de-
vice
Check superheat and subcooling– replace
X Defective reversing valve Perform RV touch test
X X Unit undersized
Recheck loads & sizing. Check sensible, cooling load and heat pump ca-
pacity
X X
Scaling in waterside heat
exchanger
Perform scaling check and clean if necessary
X X Inlet water too hot or cold Check load, loop sizing, loop backfill, ground moisture
High head pressure X
Reduced or no water flow
in cooling
Check pump operation or valve operation/setting. Check water flow; adjust
to proper flow rate
X Inlet water to hot Check load, loop sizing, loop backfill, ground moisture
X
Scaling in waterside heat
exchanger
Perform scaling check and clean if necessary
X X Unit overcharged Check superheat and subcooling
X X
Non-condensable in
system
Vacuum system, reweigh in charge
Low suction pressure X
Reduced water flow in
heating
Check pump operation or valve operation/setting. Check water flow adjust
to proper flow rate
X
Water temperature out of
range
Bring water temp within design parameters
X X Insufficient charge Check for refrigerant leaks