Air Conditioner Condensing Unit Frozen - Richard - Early last month we turned our air conditioner on and it worked fine for a few days. Then I noticed it was getting a little warm in the house so I went around and checked the Air Conditioner.

Air Conditioner Condensing Unit Frozen | AC Repair

Air Conditioner Condensing Unit Frozen | HVAC Troubleshooting

Old Condenser

Air Conditioner Condensing Unit Frozen | AC Repair - Of course, I checked the thermostat first and then the air filter. I went up into the attic to look at the air handler. I did not notice anything out of the ordinary that I am not used to seeing but I am not an expert. Then I went out to the condensing unit on the back patio and I saw some ice inside the condensing unit.

The compressor and all the pipes connecting to the compressor were a block of ice and frozen solid. I turned everything off and called the HVAC contractor I am used to dealing with. They told me they would send someone out to take care of it. A few hours after making the call I got a call from the technician. He told me it is probably very little he could do for me now as we would have to let the ice melt before he could properly troubleshoot the problem.

We agreed for him to come the next morning to check it out. He told us to leave the air handler blower fan on but make sure the condenser was off. He told me to go to the breaker box and turn the condensing unit off and use the thermostat for Fan Only operation. We did exactly as he said.

Air Conditioner Condensing Unit Frozen - Frozen Air Conditioner | The Disaster

To make a long story short sometime during the night the pan(s) under the air handler filled with water and spilled over.

frozen air conditionerEventually, the ceiling became waterlogged and caved in all over our living room furniture. It was a mess and terribly upset my wife. It’s been a few weeks and we have finally got everything back to normal again including having the air conditioner repaired. What I want to ask is: Should I ask the contractor to pay for the ceiling and cleaning up the mess?

I had no idea the air handler would flood over like that and make a mess of my living room? He was the professional so shouldn’t he have known? I just keep thinking he should of at least warned us that this would be a possibility? I like your advice and often recommend your site to others. Can you please sort this out for me? Thanks - Carl

Air Conditioner Condensing Unit Frozen | Advice

Carl……….I have seen this happen before but not in the order that it happened to you. I often tell people to do the same thing. Especially when I get a call and the customer tells me there is ice on their condenser or air handler. Sometimes the ice is on the pipes or refrigerant lines. Furthermore, if you can visibly see the ice on the outside or the inside there is probably a ton of ice inside the air handler where the evaporator coil is frozen solid.

When you find a frozen compressor or one with as much as you describe inside the condensing unit I can guarantee you have a frozen evaporator coil. Evaporator coils inside the air handler unit. The freezing can be for various reasons. However, a frozen air conditioner whether the evaporator coil is frozen or the condenser is frozen is not good. It will not function properly until you get rid of the ice and fix the problem. Furthermore, the problem of what caused the air conditioner to freeze up in the first place. Lastly, this is another example of water damage caused by an air conditioner.

Heat Pumps Freezing in Cooling Mode

Air Conditioner Condensing Unit Frozen | AC Repair

Now we could also be talking about a heat pump system in cooling mode. Heat pumps can freeze up in cooling mode also as a heat pump is an air conditioner in cooling mode. Heat pumps also freeze up in the winter but that is for different reasons than the cause of it freezing up in the summer or when the heat is operating in the cooling mode and the condenser or evaporator coil freezes up.

In this situation, whether you have a heat pump or an air conditioner the cause of the condensing unit freezing can be the same problem from the heat pump to the air conditioner. Lastly, in cooling mode, either an air conditioner or a heat pump should never produce ice or freeze up the condensing unit.

Troubleshooting the Problem of Ice in the Condenser - Airflow and the Evaporator Coil

One thing I always tell my customers is that airflow is very important. If you do not have airflow across the evaporator coil then your air conditioner or heat pump will not cool. I have written this before and I can’t repeat it enough. Make sure you have enough airflow because the evaporator coil needs to be absorbing heat from the air passing over the coil. If it does not then you are simply wasting energy.

It comes down to a few things here but the homeowner can check these things to find out for themselves if it is the problem except under the circumstance of when the evaporator coil is completely frozen over.

  1. Frozen Air Conditioner Evaporator CoilDirty Filters - the homeowner can make sure that the air filters are not clogged and preventing the proper amount of airflow from going through the system. Dirty and clogged air filters will cause an air conditioner or heat pump to freeze up.
  2. Collapsed or broken ductwork can also cause a problem with airflow. Perhaps the cable man came over to fix something or some other work was being done and they accidentally did something to cause a problem with the ductwork. It has happened before in my experience so don’t rule it out.
  3. A bad blower fan motor. Happens from time to time. A bad run capacitor or even the blower motor failing altogether could be the problem.

Air Conditioner Condensing Unit Frozen - Additional Issues to Look for

Another issue that could cause the air conditioner to freeze up is the condenser will continue to run when the air handler shuts off. That is an electrical problem that keeps the condenser running when the air handler shuts down normally as it should. The problem is in the condenser and quick fix by an HVAC technician.

Other than that what would cause the evaporator coil or the condensing unit to freeze up is a low Freon® or refrigerant charge. I say Freon® only because a lot of people refer to their refrigerant as Freon®. Technically it is a specific type of refrigerant that could include Freon®. In that case, a refrigerant leak check is in order to make sure the refrigerant does not leak out again. A repair of a refrigerant leak is specialized and can take some time but a true professional can take care of the problem and offer you a warranty on their work.


Air Conditioner Condensing Unit Frozen | AC Repair

Now, Carl, as far as your ceiling is concerned it is nearly impossible to see every possibility with every customer. I am only guessing but it could be the drain on your air handler was clogged. The condensation drain that drains the condensate off the evaporator coil can become plugged up and spillover. It is possible that both primary and secondary condensation drains became clogged. In that case, a float switch should have been installed in the secondary drain pan so that in the event that the pan overflowed it would kill power to the unit.

Who did your annual maintenance? Furthermore, if no one then you can only blame yourself. If it was done recently it’s time to ask the contractor that did the annual maintenance on the air conditioner. I would say turn it into your homeowner’s insurance and leave it there. Lastly, good luck Carl and I hope my answer helps you.

High Performance HVAC articles on air conditioner repair and diagnosis can be found here.

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