Learning About Furnaces

Troubleshooting A Ductless Mini-Split A/C With Moisture Buildup

A ductless mini-split air conditioner is a good choice for homes that want more efficient cooling without having to tear open walls to place new ductwork for a central unit. The ductless unit has an outside condensing unit, as do central units, but can have a few air handlers inside compared to the one for a central unit. So troubleshooting checks involve more parts, but work similarly to checks with a central unit.

If your ductless mini-splint air conditioner is showing signs of a moisture buildup in the air handlers, there are a couple of troubleshooting steps you can take – or leave the job to air conditioning contractors.

Icy Evaporator Coils

There is a set of coils called evaporator coils inside each air handler. The coils take incoming liquid refrigerant and convert it to gas so that the coils become cold. Hot air comes into the system through your vents, passes across the cold coils, and then is blown back into the house by a motorized fan.

An internal moisture buildup can happen when the coils become too cold and form ice. When the unit is turned off or into fan-mode, the ice melts. There's a drain in place to take care of the normal condensation made during cooling, but the ice can form big chunks or too much water for the drain to take care of it all.

If icy coils are a recurring problem, you need to call an HVAC technician. There's either a problem with your blower motor and fan or an imbalanced supply of refrigerant in your system. Both problems need to be fixed quickly to maintain a fully functional and efficient cooling system.

Clogged Drain

If the coils aren't icy but you're experiencing a water buildup, there's likely a problem with the drain in your air handler. There's a condensate pump inside that works to remove the accumulating moisture and flush it down a drain pipe. That pump can break or the pipe can experience a clog.

A broken condensate pump will need to be replaced by an HVAC technician. You can check to see if the drain pipe is clogged by unhooking the drain hose, holding it over a bucket, and then squeezing the hose to see if anything comes out.

If water doesn't run out freely, you have a blocked line that you can treat like an ordinary drain clog. If the water does run freely, it's likely the condensate pump that's the problem and you're back to needing an HVAC technician.

For more information, contact Century Heating & Air Conditioning Services or a similar company.


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