Why Is One Wall Unit in My Ductless System Not Heating?


The ductless heating and cooling system (a.k.a. ductless mini split heat pump) has done wonders for many homes that wouldn’t have been able to enjoy central comfort otherwise. Ductless systems are excellent for other purposes as well, such as add-on rooms, home renovation, new home construction, and eliminating hot and cold spots in homes no other HVAC system can reach.

If you enjoy ductless heating in Olympia, WA, we hope you won’t have to call us for repairs during the season. But even the best ductless mini split heat pump can malfunction. During the winter, you may discover that one of the wall units in your home isn’t sending out heat. The good news is that you won’t have to worry about losing heat in the rest of the house while this one is broken. The bad news is that you still need that one unit fixed!

Reasons for a Non-Working Ductless Wall Unit

We’ll run through a few of the basic reasons you may have a wall unit that’s not doing its job. In some cases, it may be a simple problem you can remedy yourself. In others, it’s best to call for help. Ductless heat pumps are complex refrigeration systems and require training, expertise, and special tools to repair.

  • Dead batteries in the remote: You operate the wall units using individual remotes so you don’t have to keep getting on a step ladder to make adjustments. When a wall unit isn’t responding to the remote, the first thing to do is to check the batteries in the remote. Put in fresh ones and try to adjust the unit again.
  • Broken fan: The blower runs using a motorized fan that pulls air into the top of the unit and then sends it across the refrigerant coil to be either heated or cooled. The motor can wear down and burn out. You may hear a warning sound ahead of the failure, like a screeching or shrieking sound. If you hear grinding when you try to start the wall unit, stop using it right away. You need technicians to replace the broken motor.
  • Dirty coil: The coil in the unit is where heat is released to warm up the air (or, in cooling mode, where heat is absorbed). If the coil becomes dirty or develops mildew over it, it will lower the heating power of the coil. The unit has a plastic filter to trap contaminants, but if the filter is clogged up or damaged, it will interfere with the coil. Technicians need to remove the coil to clean it.
  • Lost connection: A set of conduits from the back of the unit pass through the wall and connect to the outdoor cabinet. The conduits include a power line, refrigerant line, and condensate line. If any of these break, it will leave the wall unit malfunctioning.

You can trust our technicians to solve any problem with your ductless system. We are both electricians and HVAC professionals, so we’re in a unique position to solve issues with ductless mini split heat pumps. We’re the company to trust in Tacoma and the Puget Sound area.

Resicon LLC is committed to improving the lives of our customers. Request a free consultation today.

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