Frozen coil, fan not running

[FMYStreetRacer]

hello everyone, this is my first post and i hope you guys can help. here's my story.

been having some problems with my home a/c. i have come home 2 times to my house hot as hell and the air handler not blowing air but the unit outside is on. the evap is also frozen solid. this happened 2 times a month apart. i talked to a guy that was a repair man and he said it was probly a capacitor for the fan motor. wich made sense but it wasn't happening allot just those 2 times. well i was going to get around to replacing the capacators but today my power went out for a split second. immediatly i thought to myself that i should go check on the a/c cause it was running when the power went out. run outside and sure enough the condensor unit outside was running but the air handler fan wasn't and you could already see the coil starting to freeze in the air handler.

now my question, what could be causeing this? shouldn't the thermastate shut the the condenser unit off when the coil starts to freeze? could it be the thermastat is bad? it's a digital one if that matters.

every time this happens i have to cut the breaker off for the a/c for a few seconds and flip it back on and it all works fine again.

[Jedi Appliance Guy]

The Force is telling me, either your evaporator fan relay is not closing when it should or your contactor outside is not opening when it should.  Today when it was "doing it" was your thermostat calling for cooling or not.  Every time this happens would be a good time to have your meter ready.

[FMYStreetRacer]

i would assume it was calling for cooling considering the a/c was running when the power went out. when the power came back on 2 sec. later the air handler fan did not start blowing but the outside unit turned on.

is there some sort of thermostat that i can buy that has a delay if the power goes out it will wait a few minutes to turn the unit's back on?

[Jedi Appliance Guy]

The Force says you need a multimeter.  You can get one at any walmart, home depot or lowes.  Even if it's probably a fan relay, you don't "KNOW IT" till you see 24 volts to the relay coil and the power interuption to the fan motor across the relay contacts.  2 measurements.  Knowing your make model and serial of both units couldn't hurt.  Pictures will help.  

[FMYStreetRacer]

i have a Matco meter. i guess what i'll have to do is find a way to make it to it every time. then go in a diagnois. maybe flipping the main power to my house off and on real quick will work.

Edit. i know the unit's are made by Colman...lol.

[Jedi Appliance Guy]

I don't work on enough Coleman's to picture one in my head and the Force has yet to send me a vision but, if you'll open it up and take a picture of the electrical compartment we may be able to show you where to measure.  I wouldn't mess with your main breaker to try and make it do it.

[FMYStreetRacer]

cool thanks for the help. one day when i get a chance i'll jump in there and pull the cover off.

[AccApp]

A Coleman is like a York, made by the same people in Norman,OK and also sold as other brands, Luxaire and Frazer-Johnston spring to mind and there may be others.

Problem could be anywhere: T-stat, wire from t-stat to A/H, sticking relay in condening unit (not likely from what you said but still a possibility)

Most t-stats do not have short-cycle protection for power outages, it sems like it would make sense to include it. It is often built-in to the condenser, but not your unit.

[doc_cottom]

[user=10049]FMYStreetRacer[/user] wrote:

the air handler not blowing air but the unit outside is on. the evap is also frozen solid.

Have you checked your air flow? Obstructed air return (like in filter), blower motor failing, collapsed duct work, or commonly a very dirty evaporator coil. My bet, and I'm sure service men will agree, a good cleaning the entire system will cure a high percentage of air conditioner problems. I seen one direct drive blower where the motor was running just fine, but the blower was only running about one-third the speed of the motor. The blower wheel hub had broken loose, but not completly.

Doc

[applianceman18007260692]

yore thermostat is inside the house right?

 how is it gonna know if yer outside unit is freezin up?

the problem is gonna be relateed to the inside blower unit not the condenser.

either the A-coil inside is dirty or the blower motor aint funtioning

I feel like the problem might be the relay

but i need more info

 is your unit a a gas or electric heater?

 

[chris auger]

That is not true, if the thermostat is not calling for cooling but the contactor is stuck closed the unit will freeze up.

Chris

[applianceman18007260692]

true dat:dude: