Lochinvar HS 50 Series 100, User'S Information Manual

29

TROUBLESHOOTING

Problem

Possible Causes

Corrections

Heat Pump is too noisy

1. 

Sheet Metal fasteners are loose.

2. 

Operating vibration is transferring to fl oor or 
building structure.

3. 

Blower pulley assembly loose or out of 
alignment

Tighten Fasteners

Place vibration dampers underneath unit

Tighten or align pulleys

Water on fl oor around the 

heat pump and or water 

tank

1. 

Tubing, valves, or fi ttings are leaking

2. 

Heat Pump is not leveled causing drain pan 
overfl ow

3. 

Condensate trap not installed properly

4. 

Drain pan overfl owing

5. 

Condensation forming on the bottom of unit 
(humid environments)

Repair leaks as necessary

Shim unit to level, See installation section

Condensate trap depth must maintain a water column 
during operation

Use pipe snake or compressed air to remove obstruction

Cover bottom of unit with foam insulation

Heat Pump is not running 

- Electrical issues

1. 

Circuit does not have adequate ampacity

2. 

Short circuit or loose connection in fi eld wiring

3. 

Short circuit or loose connection in the 
cabinet

4. Thermostat 

Failure

5. 

Defective anti-short cycle timer

6. Compressor 

burn-out

Refer to nameplate for unit requirements

Check fi eld wiring diagram, Tighten all connections

Check for loose wiring and tighten

Replace thermostat

Reset phase monitor

Replace Compressor (refer to compressor change-out 
page)

Heat Pump is not running 

- High Pressure Fault

1. 

Thermostat setting too high

2. 

Air temperature over 95

°

 F

3. 

Low water fl ow causes

a. 

 External Pump is not operating

b. 

Piping between the heat pump and storage 
tank exceeds 50 equivalent feet

c. 

Heat exchanger has scale buildup

d. Shut 

off  valves are partially closed

Thermostat setting should not exceed 160

°

 F

Keep heat pump off  until room temperature is back in 
operating range

Low water fl ow corrections

Replace unit pump

Reduce piping or add booster pump

Clean heat exchanger with a mild acid wash

Open all shut off  valves

Heat Pump is not running 

- Low Pressure Fault

1. 

Room temperature below 40

°

 F

2. 

Blower not operating at nameplate CFM - 
blower belt is broken or out of alignment 
fi lters are dirty

3. 

Unit does not have adequate clearances 
obstructing air fl ow

4. 

Loss of Refrigerant

Keep heat pump off  until room temperature is back in 
operating range

Correct air-fl ow issue

i. 

Replace or realign pulley assembly; tighten belt at 
the adjustable pulley

ii. Replace 

fi lters

iii. 

Relocate unit to allow for even air fl ow

Find source of leak, repair, and recharge

Water is never hot enough

1. 

Thermostat setting is too low

2. 

Heat pump/storage tank undersized for 
application

3. 

Heat pump is not properly connected to 
storage tank.

4. 

Unit cooling coil is over cooling the space

Set thermostat for storage tank to a higher temperature

Increase size of storage tank or install gas or electric 
heater to make up for shortfall

Refer to fi eld piping diagrams for recommended piping

If the room air temperature is too cool a) Use back up 
water heating  b) Duct  cool air to another space  c) duct 
warmer air from another space to the installed room

*Reset the heat pump by removing then restoring power to the unit at the breaker or from the manual switch. (There will be a three minute delay before heat 
pump restarts.) If the heat pump cuts out again on LOW or HIGH PRESSURE, additional troubleshooting is necessary to fi nd the cause. 

DO NOT CONTINUE TO RESET THE HEAT PUMP, AS CONTINUED SHORT-CYCLING MAY STRESS OR DAMAGE INTERNAL COMPONENTS