Can high humidity cause compressor not to run?
#1
10-01-15, 07:52 AM
Can high humidity cause compressor not to run?
My Sears air conditioner model 867.816940 (no heat pump) is 24,000 BTU cooling 900 sq. ft. and more than 25 years old but operating fine until yesterday when the outlet vents were blowing out no cool air. Outside temp was 83 degrees and humidity in 90 percent range.
Here's what I checked: intake vent clear, new filter turned right way, no ice on evaporator coils, blower fan running, fuses good, checked contactor and no obstruction (bugs) and it's only a few years old (I replaced it myself and all wires connected snugly). Outside condenser fan running but blowing no warm air, not removing anything from inside temp which was 76 degrees and going nowhere. After an hour of the unit running and making no progress, I decided to cut it off.
My guess was compressor either wasn't running or freon had escaped line. I had it recharged in the spring with freon and it has a small pinhole leak but always holds at least a year before needing more (leaks out during winter). I've got a multimeter good for testing up to 200 V but didn't know where to attach it to see if compressor was actually running or receiving good voltage but since outside condenser fan was running, I knew voltage was getting through contactor.
Here's the surprise--after leaving it off about an hour (again, no ice buildup), I turn it on and still blowing no cool air for about 30 minutes... then cool air starts blowing out and inside temp starts going down. Cool air blows until thermostat clicks it off. It begins running normally the rest of the evening, on then off. But for a couple of hours there was no cool air and I can't figure out what happened. I never jiggled any wires.
Does the high humidity have any role in this temporary failure? Where should I put multimeter test leads to see if compressor is running/getting voltage (I'm afraid of high voltage capacitators--do these just fail or can they intermittently work and not work)? Any ideas on what to look for would be appreciated.
Regards, Cletus
Here's what I checked: intake vent clear, new filter turned right way, no ice on evaporator coils, blower fan running, fuses good, checked contactor and no obstruction (bugs) and it's only a few years old (I replaced it myself and all wires connected snugly). Outside condenser fan running but blowing no warm air, not removing anything from inside temp which was 76 degrees and going nowhere. After an hour of the unit running and making no progress, I decided to cut it off.
My guess was compressor either wasn't running or freon had escaped line. I had it recharged in the spring with freon and it has a small pinhole leak but always holds at least a year before needing more (leaks out during winter). I've got a multimeter good for testing up to 200 V but didn't know where to attach it to see if compressor was actually running or receiving good voltage but since outside condenser fan was running, I knew voltage was getting through contactor.
Here's the surprise--after leaving it off about an hour (again, no ice buildup), I turn it on and still blowing no cool air for about 30 minutes... then cool air starts blowing out and inside temp starts going down. Cool air blows until thermostat clicks it off. It begins running normally the rest of the evening, on then off. But for a couple of hours there was no cool air and I can't figure out what happened. I never jiggled any wires.
Does the high humidity have any role in this temporary failure? Where should I put multimeter test leads to see if compressor is running/getting voltage (I'm afraid of high voltage capacitators--do these just fail or can they intermittently work and not work)? Any ideas on what to look for would be appreciated.
Regards, Cletus
#2
10-02-15, 04:53 AM
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#3
10-02-15, 05:25 AM
Member
High humidity should have no effect. I have run my AC most of the summer with outdoor humidity levels at 90-100%
Also you HVAC tech is breaking the law by recharging your unit with a known leak.
Also you HVAC tech is breaking the law by recharging your unit with a known leak.
#4
10-02-15, 05:56 AM
Member
Also you HVAC tech is breaking the law by recharging your unit with a known leak.
In Canada you must repair the leak first. In the USA it is permitted to fill residential systems without any leak repair.
#5
10-02-15, 06:05 AM
Member
Does the high humidity have any role in this temporary failure? Where should I put multimeter test leads to see if compressor is running/getting voltage (I'm afraid of high voltage capacitators--do these just fail or can they intermittently work and not work)? Any ideas on what to look for would be appreciated
#6
10-03-15, 01:50 PM
Member
Thanks for the clarification Bob, I thought it was law everywhere that a known leaky system must be fixed before it is recharged.
#7
10-03-15, 03:12 PM
Super Moderator
It is possible that your problem is related to the leak.
It could again be low on refrigerant, the leak could be on the low pressure side and some air has been drawn into the system or being repeatedly low could have overheated the compressor which could cause similar symptoms.
You may want to find a different service person who is willing to look a bit deeper into your problem.
It could again be low on refrigerant, the leak could be on the low pressure side and some air has been drawn into the system or being repeatedly low could have overheated the compressor which could cause similar symptoms.
You may want to find a different service person who is willing to look a bit deeper into your problem.
