My mini split unit operates but will not cool. What can I do to fix this problem?

A. Check filters in the indoor unit. If filters are dirty clean or replace.
B. Check to make sure there is no blockage around the indoor or outdoor unit.
C. Check for proper suction pressure.

1. Suction pressure should range between 60 and 70 PSI
2. If pressures are too high, you will have to remove small amounts by evacuating lines until suction pressure is in range.
3. If pressure is too low. You will need to add refrigerant. If the mini split unit “RUN Load Amps” are more than two times the stated “RUN Load Amps” on the label of the outdoor unit label, replace capillary assembly.
4. The mini split unit will also not cool in low outdoor temperatures. There are low ambient kits to help run your air conditioner in temperatures below freezing.

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Window Unit vs. Mini Split Efficiency

Written by:  Jackie S.

Problem:  Not a problem.  I have a Whirlpool 15,600 btu. window unit through the wall.  It cools to 70 degrees at a reasonable cost.  My question is can I expect an 18,000 btu. mini ductless to perform equally to my Whirlpool or better?  The sizing is right, I just don’t want to get too large or too small of a mini split air conditioner.

Solution: A mini split air conditioner will be a much more economical system than a window through the wall air conditioner.  Older window units are at or below 10 SEER.  Ductless mini split systems start at 13 SEER and at the 18,000 btu. size reach up to 16 SEER.  A 13 SEER unit will save over 30% on your utility bill versus a 10 SEER unit.  Also, mini split systems are much more quiet than a window unit.

Replacing Just the Evaporator of a Mini Split.

Written by Megan A:

Problem:

My inside evaporator will not come on.  I have checked the power, checked the fuses inside the cover, changed the batteries in the remote. Can I use the same compressor and just buy the inside unit or do I have to buy the compressor and evaporator. I have looked everywhere and can not find just the inside unit. I hate to throw away the compressor.

Solution:  After checking that power is indeed reaching the indoor evaporator and the fuse is still intact you most likely have a circuit board failure.  Many manufacturers call it a “PCB Board” and it is a relatively easy repair.  Call your manufacturer to purchase the correct part.  Most manufacturers will have a one year warranty on the circuit board.

If you need to purchase a new evaporator there should not be a problem swapping it with the older unit.  Make sure the model number of the new evaporator matches the old evaporator.  A HVAC installer will be needed to vacuum the line set and recharge the entire system’s refrigeration.  The only difficulty I see is if you have an older 10 SEER evaporator and the only thing available is the newer 13 SEER evaporators.  The two systems will not be compatible.  You will also have to find a distributor that will sell only the evaporator.