Water Source Heat Pumps FAQ

LV Models

LV Models

The fan runs, but the compressor is not operating. The UPM board's LED is blinking THREE times. What should be checked?

This indicates that a "Condenser Freeze Condition" has been detected.

A condenser freeze may only occur in heating mode when the water coil is now on the low pressure side of the refrigeration operation.

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For further details on all of the points below, please refer to the product's manual (available for download HERE).

1. Low (or no) Water Flow Through The Coil

a. Check water valves and pumps for correct operation.

b. Check for blockage in the water coil.

2. Low Water Temperature

a. Check the water temperature, is it below 40º entering?

b. Is the heat pump connected to a closed loop with antifreeze? If so, check that the "FREEZE 1" resistor on the UPM board has been cut to set the unit to antifreeze mode.

3. Low Refrigerant

a. Check refrigerant pressure with your gauge set.

4. Poor Water Heat Exchange

a. Check for scaled water coil.

The fan runs, but the compressor is not operating. The UPM board's LED is blinking FOUR times. What should be checked?

This indicates that a "Condensate Overflow Fault" has been detected.

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For further details on all of the points below, please refer to the product's manual (available for download HERE).

1. Poor Condensate Drainage

a. Check the condensate pan to see if the water level is high.

b. Check the drain line and pan for blockages, inadequate trapping, or double-trapping.

2. Blocked Return Air

a. Check air filter for clogging.

b. Check return air duct for blockages.

c. In free-return applications, check that there is adequate space between the return air opening and walls (or other obstructions).

The fan runs, but the compressor is not operating. The UPM board's LED is blinking SIX times. What should be checked?

This indicates that an "Evaporator Freeze Condition" has been detected.

An evaporator freeze may only occur in cooling mode when the air coil is now on the low pressure side of the refrigeration operation.

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For further details on all of the points below, please refer to the product's manual (available for download HERE).

1. Freeze Fault, Air Coil - No (Or Low) Air Flow

a. Check fan motor for correct operation.

b. Check air filter for clogging.

c. Inspect air coil for dirt or debris clogging.

d. Check duct work for obstructions (including if dampers are closed or blocked).

2. Freeze Fault, Air Coil - Blocked Return Air

a. In free-return applications, check that there is adequate space between the return air opening and walls (or other obstructions).

3. Freeze Fault, Air Coil - Low Refrigerant

a. Check refrigerant pressure with your gauge set.

The fan runs, but the compressor is not operating. There are NO blinks on the UPM board's LED.

This may indicate that the contactor is not energizing.

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For further details on all of the points below, please refer to the product's manual (available for download HERE).

1. Is The Thermostat Calling For Compressor To Operate And Is It Sending 24vac To The Heat Pump?

a. Ensure that thermostat is on and is calling for "Y".

b. Check "Y" connection from thermostat, and ensure that there is 24vac across "Y" and "C" terminals in heat pump when thermostat is calling.

2. Possible Loose Wire To Contactor Coil

a. Check wiring to ensure that there is 24vac across the contactor coil.

3. Potential Failed Contactor Coil

a. Test contactor with 24vac across "R" and "C".

b. Ohm out the contactor coil. Open circuit indicates that the coil has failed.

I hear noises when the heat pump Is running. What could they be, and can I reduce them?

When operating, there will of course be audible sounds coming from the unit itself, or even from the air ducts and water piping in your property.

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For further details on all of the points below, please refer to the product's manual (available for download HERE).

Air Flow Noise;

1. Poor Air Duct And/Or Grille Design

a. Ensure that all ductwork and grilles are correctly sized for the unit's air flow.

b. Check for blockages or damage to the air ducts and grilles.

2. Fan Speed Setting Too High

a. Consult the blower performance table in the product manual.

Structural Noise

1. Unit Not Mounted On A Full Anti-Vibration Pad

a. Mount the unit on a suitable anti-vibration pad.

2. Unit Has Been Connected With Solid Installation Hardware Instead Of Flexible Hardware.

a. All electrical conduit, water lines, and duct work connection to the unit should be flexible, as this will help prevent noises and vibrations from being transferred from the unit to the structure. Please refer to the manual for correct installation guidelines.

3. The Unit Is Physically Touching A Wall Or Other Part Of The Building

a. Adjust the unit's mounting location to avoid physical contact with any part of the building's structure.

Compressor Noise

1. Elevated Head Pressure Caused By High Water Temperature Or Low Water Flow Rate (in cooling mode)

a. If possible, reduce the water temperature or increase the water flow rate.

2. Scaled Or Dirty Water Coil

a. Descale and clean the water coil.

3. Elevated Head Pressure Caused By Low Air Flow (in heating mode)

a. Check the air filter for clogging.

b. Check the duct work for blockages or damage.

c. Increase the fan speed.

Water Hammer

1. Fast closing valves were used when installing the unit.

a. Replace the fast closing valves with a slow-close type instead.

Can the heat pump's fan speed be adjusted?

There are multiple motor types that are available when the customer is selecting the specifications for the LV heat pump, and all but one of them do offer fan speed adjustment (the 575v PSC motor option is single-speed only).

Safety Notice - This is a high voltage product and contains refrigerant. Only professionals who are qualified to work on such equipment should do so.

For fan speed adjustment details, please refer to the product's manual (available for download HERE).

Are there water quality requirements that must be followed?

Yes.

Please refer to this service bulletin for a description of the water quality requirements for our water source heat pump products; LINK

Can the water coil be acid cleaned?

Yes.

Please refer to this service bulletin for further details of how to clean the water coil; LINK