If you’ve ever experienced an HVAC breakdown in the middle of winter, you know that it’s not just a luxury but a necessity to get it up and running. Fortunately, most of the time you don’t need a whole new HVAC heating system to fix the problem.
One reason why heating systems malfunction during winter is because the unit gets iced up. There are quite a few reasons for the unit to get iced over, some of them solved by the homeowner (although more of them do require a HVAC technician). Let’s find out how to handle an iced-over unit.
How an HVAC Heat Pump Works
The truth is that HVAC systems are designed to self-defrost whenever it’s needed. This means that a thin layer of white frost or light ice may cover the heat pump in your Nashville, TN HVAC unit, but if it’s not just caked in ice and you aren’t having any heating problems, you don’t need to worry. When this thin layer develops, the system should kick into defrost mode.
A defrost cycle should only take up to 10 minutes, as this helpful blog post explains. What happens is that the unit shuts off the outside fan, allowing the refrigerant circulating inside the system to get very warm, melting the ice. You may see your thermostat running on auxiliary heat at this time—the system actually switches over to air conditioning to allow the outdoor evaporator to become a condenser, and the back-up heat warms your air until defrost is done. When the outdoor sensor reaches a certain temperature, the system switches back over to normal heat and a “whoosh” sound is heard from the outdoor unit. This is the refrigerant reversing direction.
Your heat pump is very efficient, but sometimes adverse situations cause it to ice up and malfunction. You want to catch such a condition as early as possible to avoid losing the unit entirely. The warning signs described in this post say that when you notice airflow problems in the house, it’s time to take a look at the HVAC unit. When you notice that your house isn’t heating properly and it’s been a cold Nashville winter, it’s a good idea to step out to the HVAC unit.
Reasons for Icing Over
There are a lot of reasons your heat pump may be icing over. Let’s look at the ways you can make a DIY repair:
- Outdoor coil is blocked by snow or leaves—clean it out
- Unit is sunk into the ground—raise it up to allow ice and condensation to drain off
- A leaking gutter is allowing excess water to fall on the heat pump and freeze over—fix the gutter
- Freezing rain—the top of the unit can freeze over, so go out with a water hose to wash away the ice
However, if none of the above seem to be occurring with your unit, it’s time to call in a professional. The problem can be things like malfunction of heat pump controls, low refrigerant charge, or a worn-out motor, all of which require the attention of a HVAC technician.
If you’re noticing heating problems in your house, you may want to do a quick inspection of the HVAC unit to ensure that no ice is coating the heat pump.
Has your HVAC ever iced up in winter?
Even though most of our winters in Nashville tend to be mild, we do have sudden strong ice storms and moments of random freezing rain. It’s a good idea in these times that if your house suddenly doesn’t feel warm like it used to, go out and look at the HVAC unit to check for ice. You don’t want to lose it to ice in the middle of winter!
Have you ever needed an HVAC technician out to fix the heating on your unit? Has your heat pump ever iced over? Tell us your experience—we want to know, and we’ll respond right away!