Why is my A/C condenser compressor overheating, causing compressor to turn on and off every 4 minutes?

Robert Moller

• 1524 Answers

SOURCE: Compressor freezes up at night and some during day.

You are being ripped off. The ambient (outdoor) temperature at night is low and therefore proper condensing does not take place causing the refrigerant to pool in the condenser and starving the evaporator. This causes a lower temperature in the evaporator resulting in "freeze up" which is often mistaken for a loss of refrigerant.
The proper thing to be done is to block off the condenser air causing the high side pressure to rise until the eqivillant of 110*F condensing temperature.
You can also install a low ambient kit which will cycle the compressor off when the temperatures fall

Posted on Jun 07, 2009

SOURCE: Carrier air handler tonnage?

That is a fairly large difference. It is usually ok to have the inside evap. coil and blower up to 1 ton larger than the outside condenser. That will make the unit slightly more efficient as well as less likely to freeze up on low airflow situations. It is not recommended to install a new condenser on an old evap coil. There has been a lot of changes to the design of the coils in the last little while. For example a 10 year old 2 ton coil may only have 3 cubic feet of volume but a new 2 ton coil may have 4 cubit feet of volume.

There are many factors that may have infulenced the decision on what size condenser to install. Many of which can only be done by visiting the home and doing alot of work, checking the duct sizing bioth supply and return, inspecting the insulation and windows of the home etc. etc. Most of the time that never gets done. You can blame the contractor for not doing a complete check, but at the same time you can blame the customer because many contractors that are that good loose the job to a cheaper bid that did not no any of the research. It is a catch 22 for everyone involved.

There is ALOT more to sizing equipment that many people think, sadly that also includes many HVAC contractors. Way too many people use "rule of thumbs" or flat out "guess".

Sorry for the rant but your queston can only be answered by a good well educated HVAC contractor visiting your home. That type of a contractor is getting hard to find these days in such a price competetive world.

Posted on Oct 14, 2008

SOURCE: Trane AC Compressor fan cycling on and off.

it depends on the tempareture you have set that is why it was going on and off

Posted on Sep 09, 2009

SOURCE: 3 ton condensor and 2.5 air handler

I hate to use rules of thumb but 500sqft per ton depending on your windows and insulation. you are probably ok with a 2.5 ton however it will not work with a 3 ton outdoor unit as you have figured out. depending on how long that ac has been in you may want to replace it with a 2.5 ton due to the damage to the compressor valves because of the mis match. or if the indoor is newer and the original system may have been a 3 ton then i would replace the A/H. and be prepared to replace the outdoor if the valves are to far gone. If the trane is a new high effiency 2 and the goodman is just a 10 SEER you may be able to have a txv installed on the trane unit and a kickstart device outside. but only if its a high effiency but their again if the A/C fails you couldnt have a high effiency 3 ton you would have to drop down to 2.5,

Posted on Sep 22, 2009

SOURCE: I have a 3 ton split system using a Rudd 3 ton

Both the other solutions are NOT proper Advice, i'm not saying this a put down, but if you want it to be right both of those answers are wrong
The truth is if you replace the condenser weather its a heat pump or strait cool, you need to match the equipment inside, ALWAYS use matched equipment otherwise your setting yourself up for failure. I've seen a ton of mechanics in my industry really mess people up by mis matching, Also you can install or service anything with refrigerant in it with out an EPA license. Trust me do it right, cause I hate having to tell people after its to late. Another thing these two are not telling you is that you need to match the metering device to the outdoor unit in order for it to work properly as well, and by the FLUSHING is risky on a coil, ok with line sets but risky with a coil.

Posted on Oct 01, 2010