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Cool Touch Air Conditioning and Heating Blog

Diagnose Your AC Unit

Here are instructions on how to troubleshoot your air conditioning system. To diagnose your air conditioner or HVAC system in an ordered, methodical and proven way to get the answers you need, you have to take some time, get educated, and this will save you a lot of money. Commission based A/C techs love nothing more than an ignorant consumer. They can sell you anything from a surge protector to float switch, even up to a new unit for a simple run capacitor or burnt wire.

Experienced HVAC companies will take the time to explain things and provide the best service possible with honesty and integrity.

First question in the diagnosis:

1) Is air blowing from the registers? Yes or no

If yes, then go through this check list:

A) Is the condenser fan motor and compressor also operating?
B) If all motors are operating and you are getting warm to ambient air than probably a refrigerant issue.
C) That can come in the form of low refrigerant, slow leaks, big leaks,
leaking reversing valve if the heat pump is clogged.
D) If air is warm at registers check condenser fan motor and compressor.
E) Does the condenser fan blade turn freely with a long-handled screwdriver? or is it binding up?
– binding up usually means it is seized up
– test the run cap first before replacing the condenser fan motor
F) Compressor may or may not start back up if run cap on fan motor is popped
– it has an internal overload protection that must reset at appx 115 degrees to operate again.

2) Is there air at the registers?
A) It may be cool but very low airflow
– dirty evap coil
– leak in ductwork
– very dirty filter
– if this is the case the compressor and outdoor fan motor will probably trip on overload

Referring back to question #1 above, if the answer is No then review this check list:

A) when you operate the thermostat does any other modes work (fan to on or heat)?
B) Is there ice on the big copper pipe (suction line) when the outdoor unit (compressor, condenser fan motor) comes on?
C) If yes than shut off the system.
D) If No and all other modes are shut down, this maybe an issue with:
– control problem
– change batteries in t-stat
– float switch backed up
– 5amp fuse in air handler (there is a reason it popped – gotta find out why)
– transformer blew (it happens)
– bad wiring
– main breaker for whole unit

This is just a short list to help get you going and to provide steps in the proper way to diagnose your air conditioner. If you feel you need an expert please don’t hesitate to call one of our experienced techs at Cool Touch to come out and give you a hand. Choosing the right AC company to help you with a complex problem is very important so feel free to browse our customer reviews section.

Cool Touch 623-584-3762

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