Problem with Your Heat Pump? - Heatmasters
4 minutes read

Problem with Your Heat Pump?

Published by Steven Weiland

With this guide, you can determine common heat pump system issues and repair any as needed.

There is ice on my heat pump.

Outdoor heat pump coils maintain a temperature below 32 degrees Fahrenheit during normal heating operation, causing frost and ice to form from air moisture. If it is humid outside, more frost will form on the unit. Your heat pump has a built-in defrost cycle, which should melt off any frost.

If the frost fails to melt, continues to get thicker, or turns to solid ice, the defrost cycle is most likely malfunctioning. If your heat pump experiences any of these symptoms, call for a repair.

Steam is rising from my heat pump.

The typical heat pump system defrost cycle works like this:

  • A sensor will measure the operating temperature of outdoor coils – if they are below freezing, the unit will go into the defrost cycle every 90 minutes.
  • In this defrosting cycle, the outdoor fan stops, the compressor continues running and the unit switches to air conditioning mode. This process causes the outdoor coils to heat up and melt off any frost or ice that may have accumulated.
  • The back-up electric heating coils in the furnace come on in order to maintain the temperature inside the home while the system is in air conditioning mode. The light on your thermostat will indicate that this back-up heat is running.
  • This defrost cycle will typically last until the coils reach a predetermined temperature, or for 10 minutes, whichever comes first.

During this process you may see steam pouring off the outdoor unit that looks like clouds of smoke. It is a perfectly normal result of the melting frost on your heated coils.

Nothing on my heating system is working.

If this is the case, there is probably an electrical problem in the system. This is what you should do:

  • Check all circuit breakers, as they can sometimes be tripped even if they look like they are on. Reset the breakers by turning them all the way off and then back on again.
  • Make sure no power switches have been turned off. Many gas and oil furnaces have power cut-off switches mounted in your basement, or on the side of the furnace.

If all switches and breakers seem to be fine, call a professional to come take a look.

My unit is making a strange noise.

The only noises you should be immediately concerned about are banging, scraping, clanging or loud vibrations. Low humming, buzzing, and pressure relief noises are generally normal. If you hear any loud noises coming from the indoor or outdoor unit, turn the system off right away.

The back-up light on my thermostat is always on.

The back-up light is a signal that the back-up electrical coils in the furnace are energized. There are three times when this is normal:

  • As mentioned above, the heat pump system brings on the back-up heat when in the defrost cycle to compensate for the system being in air conditioning mode.
  • This back-up heat also comes on when the temperature inside falls more than two degrees below the setting on the thermostat. Similarly, the back-up heat will come on if you raise the thermostat more than two degrees.
  • As it gets colder outside, you will see the back-up light more often. This is due to the outdoor unit being unable to produce enough heat by itself to maintain the indoor temperature.

When outdoor air temperatures fall below 35 to 40 degrees Fahrenheit, expect this back-up light to turn on and off on a regular basis. If you notice the light on more than usual during milder weather, your outdoor unit may not be operating properly.

If it still seems that your unit is not working, contact Heatmasters for maintenance and repairs.

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