GE central heat unit - mercury - please help lady diy attempt!

[nijoli]

NEW PROBLEM IS A FEW POSTS DOWN IN THIS THREAD -

Here are the stats off the device on the wall:

8403-171

3AAT80A5b11

30volt AC 1.5 AMP

8416

Here is the problem I am having:

The air worked fine all summer, and the heat worked for 15 minutes until my boyfriend said "Hey look! When you move the heating side, the air side moves, too!" and wiggled the temperature changing thingies back and forth. Immediatly the heat went off and the air won't come on, either

Picture of the device:

[dkpd1581]

Here is an easy fix to try.  Your control board possibly got mad at your boyfriend when he moved the t-stat back and forth between heat and cool mode - this is called short cycling.  Find the air hadler (the indoor unit where the filter gets changed) and turn off the power to it.  The disconnect may be a simple light switch, a larger box with a handle, or it all else fails - find the breaker in the box and turn it off. 

Once it is off, count to about 10 to give any electrical components time to power down and turn it back on.  This should reset any fault caused by messing with the t-stat.

If it does not work, let us know and we can move on from there....best luck.

1*

[nijoli]

THAT WORKED!

I am thrilled that I registered here and everyone is impressed with my skills.

Thank you so much - I hope you realize how much your expertise helps folks out and saves them money!

- Heather

[nijoli]

Same unit. Different Problem.

The stats of the device are shown in the above post but now *here* is the new (and way worse on an 80 degree day) problem:

The blue CHECK LITE is on and the a.c. is completely shut down. I unplugged the unit and shut off the breaker like last time but it was to no avail.

I felt the side of the device and it is ICE cold. Can they freeze up?

What to do? What to try?

Advice?

thanks in advance.

[dkpd1581]

Yes your machine can freeze up for a number of reasons:

1 Dirty clogged filter

2 Indoor blower motor bad and not turning

3 Indoor blower motor wheel dirty or damaged

4 Low refrigerant

Thaw the machine out

Change the filter

Go to the t-stat and switch the FAN to ON and see if it in fact comes on

Turn the AC on and see if the air comes out cold approximately 55F

Did you try running the AC when the outside temperatures were 65F?

Did you turn down the AC at the t-stat very low and leave it there by accident

There are numerous reason why a machine would freeze - and yes they will freeze several inches thick even in the dead of summer on 100F days. Start with the things in bold italics above and report back fix it girl.

[nijoli]

How do I thaw it out? Just leave it off for a few days?

"clueless"

[dkpd1581]

Turn the t-stat to OFF, turn the fan to ON, the fan will blow warm air over the frozen coil and eventually melt the ice (time depends on the degree of ice thickness).  While it is melting the ice, you will actually get some cooling effect - ever heard of and Ice Box - that old thing grandma used to tell you get your desert out of???

[nijoli]

This will sound crazy, but I went to do just what you suggested and found something weird.

I didn't hear anything happen when I turned the fan on, so I went into the utility closet and pulled the filter aside and felt the coils underneath and they ae no longer freezing cold like they were before and there is no ice at all. They are room temperature.

But it still isn't working.

So, I turned off the breaker (which is just beside the unit) and thought I would wait for you instructions.

(thanks so much for helping me, despite the fact that i am clueless)

[dkpd1581]

With the door closed on the air handling unit (they usually have a door interlock system that removes power when its opened) and the the t-stat set to ON, if there is nothing happening, no vibration, no noise, then you will most likely want to call someone to work on your unit - unless clueless means that you know how to use an electrical meter and have some fundamental understanding of electronics.  If not - make the call.