Manual 2100-479
Page 9 of 11
TroubleshooTing The Mechanical sysTeM
HEAT PUMP — HEATING
LOW SUCTION — LOW HEAD PRESSURE
1. Restrictedairowthroughoutdoorcoil.(Restrictedwater
owthroughwatercoil.)
2. Defective outdoor motor. (Defective water pump.)
3. Low outdoor air temperature. (Low water
temperature.)
4. Frozen outdoor coil. (Frozen water coil.)
5. Restricted liquid line, dryer, metering device, etc.
6. Low charge.
7. Low indoor air temperature.
HIGH SUCTION — LOW HEAD
PRESSURE
1. Defective or broken valves.
2. IPR valve open.
3. Defective reversing valve.
LOW SUCTION — LOW HEAD
PRESSURE
1. Restrictedairowoverindoorcoil.
2. Defective indoor fan motor.
3. Low indoor temperature
4. Iced indoor coil.
5. Restricted liquid line, dryer, metering device, etc.
6. Low charge.
7. Low ambient entering air temperature. (Low entering
water temperature to water coil.)
HIGH SUCTION — LOW HEAD
PRESSURE
1. Defective or broken valves.
2. IPRV valve open.
3. Defective reversing valve.
AIR CONDITIONING AND HEAT PUMP — COOLING
LOW SUCTION — HIGH HEAD
PRESSURE
1. Partial restriction and then overcharged.
HIGH SUCTION — HIGH HEAD
PRESSURE
1. High entering outdoor air temperature. (High entering
water temperature.)
2. Lowairowoutdoorcoil.(Lowwaterow.)
3. Overcharged.
4. Air in system.
5. Restricted outdoor coil. (Restricted water coil.)
6. High indoor air temperature.
Water source heat pump.
LOW SUCTION — HIGH HEAD
PRESSURE
1. Partial restriction and then overcharged.
HIGH SUCTION — HIGH HEAD
PRESSURE
1. High entering outdoor air temperature. (High entering
water temperature.)
2. Lowindoorairow.
3. Overcharged.
4. Air in system.
5. Restricted air coil.
6. High indoor air temperature.
Water source heat pump.