Forest (Whirlpool) 6,200 BTU portable air conditioner

[Tamerlane]

Hi there, I have had this unit for a about three years and it seems to be continually freezing up now. It did this once before a while back but obviously because I hadn't cleaned the filter for a long time. More recently, it froze again so I cleaned the (already pretty clean) filter. Froze up again, so I removed the cover and discovered the inside rear fins were fairly clogged up with dust, so I cleaned this up too, thinking I had finally found the possible source of the problem.

Well, again tonight it has frozen up so I am out of ideas. The fan spins normally and the unit otherwise cools effectively. I don't want to replace it because it installs in a bedroom 5 feet from the pillow, and I had trouble finding a model as quiet as this one.

Thanks for any advice.

[RegUS_PatOff]

... continually freezing up now.

pictures ?

[Budget Appliance Repair]

Maybe the evaporator is still not completely clean. If you had never cleaned it will be clogged pretty good all the way thru, sometimes the evaporator can be separated into two sections to aid in cleaning bad clogged fins. Be careful to not bend any of the tubing sharply, just gentle bends.

[Tamerlane]

I don't have a picture of the freezing because, strangely, it has not happened again. I will attach a pic when/if it reoccurs. The night of my first post, after the ice thawed, I removed the front A/C cover with filter for the night, and thankfully the unit did not freeze in the night. The next day I carefully cleaned up the front coils and restored the cover (without filter this time), and so far so good.

But the freezing seems to happen only when the compressor stays on for an especially long time, after the A/C is turned on and has to cool a hot room.

I will keep monitoring but it sounds like the prime suspect is still blockage of air flow?

[Tamerlane]

Okay, froze up again tonight, after maybe 20-30 minutes of cooling off the room at the end of the day. Here's a photo:

[RegUS_PatOff]

nice picture . .

yea, that's froze-up. . .

and although the top Coil isn't frosted

(which may indicate a system leak, but nothing to worry about for now)

This looks like a sign of an air- flow problem

Is the Fan perhaps stopping, after awhile, at times ?

A/C model number ?

[Tamerlane]

Hello and thanks for following up. Sorry I was out of town. To answer the last question first, the A/C model number is Forest Air 13-04590 6200 BTU, which is a rebadged Whirlpool ACQ068PS.

When I got back last night the bedroom was nearly 90 degrees. I thought for sure the A/C would ice up again, since it usually does when the compressor runs so long. Fired it up and the compressor ran some 3+ hours straight getting to temperature, then on and off overnight. But no ice at all on the coils (just lots of condensation)! It's strange because the freeze up in the pic above started after the compressor was on for a much shorter period. The only difference I can think of is that last night the front grille & filter were completely off with coils exposed as in the picture. I don't know if that adds some evidence to the air flow theory.

On that theory, I wonder if my cleaning was not proper or thorough after ~3 years use. I admit I didn't use coil cleaner. I removed the cover, discovered the front evaporator coils a little dusty and rear (condenser?) coils even more dirty. Rightly or wrongly I used a strong vacuum with brush attachment on each coil surface and, well, now they at least look clean. As for the fan, I think it's working properly and running whenever the compressor is on, turning off only in power saving mode when the compressor turns off. I say I think because when the unit is installed I can't directly see the fan blade, but I can hear and feel the fan running and see the blower spinning.

As for the alternative leak theory, I completely missed noticing the top coil not frozen in the picture. I wish I could say for sure this is what always happens but I would have to wait for freezing again. The only other bit of info I should mention about a possible leak is something I forgot to mention. There were a couple weeks this summer when I thought I was noticing a funny smell right after the compressor turned off. I haven't noticed the smell since so I figured it was nothing.

Is there anything else I should do about air flow? I could leave the grill off to avoid freezing but this is not ideal. Or should I put the grill & filter back and try to get it to freeze, and see if the top coil stays unfrozen?

[Tamerlane]

Just to update my last post, there goes my hope that leaving the grill off would keep me frost free! New pic with even thicker ice layer, also showing no freezing on top coil.

[appl.tech.29501]

The vacuum aint gonna cut it. To properly clean the condensor the fan shround has to be removed and the condensor may have to be lifted out of the base and turned slightly to access it. You have to use coil cleaner . (outside or evaporator coil, inside of condensor coil) and rinse throughly. If that dont fix your problem chunk the unit and buy another...$100 unit aint worth a whole lotta time.

[jb8103]

When I got back last night the bedroom was nearly 90 degrees. I thought for sure the A/C would ice up again, since it usually does when the compressor runs so long. Fired it up and the compressor ran some 3+ hours straight getting to temperature, then on and off overnight. But no ice at all on the coils (just lots of condensation)! It's strange because the freeze up in the pic above started after the compressor was on for a much shorter period.

Due to the intermittent nature of the problem, I suspect a failure in the metering device. Yours is almost certainly a capillary tube or a piston (I couldn't find any tech data on this model) with no moving parts. Obstruction maybe, like tiny bits of brazing flaking off? I dunno. I do agree with appl.tech.29501 that these window units are disposable units.

[Tamerlane]

Well, I took another stab at cleaning, this time with coil cleaner. We'll see how it turns out. I would have chunked it long ago if most air conditioners weren't so loud.

I am guessing that fixing a capillary tube or piston is beyond my expertise. Fingers are crossed, I'll let you know what happens.

[RegUS_PatOff]

still looks like an air-flow problem ...

intermittent / slow Fan ?

[jb8103]

still looks like an air-flow problem ...

intermittent / slow Fan ?

Good point.

[applianceman18007260692]

This unit uses electronics to control the temp. The unit does NOT need any gas with all that ice there. What you probably have is a bad thermistor. Test it. Get a glass of ice water. With the ac working normally and all thawed out drop the end of the thermistor in a glass of ice water. the cold water should shut down the compressor. If the compressor stays going then you have verified the problem. Click here for photo

[Scottthewolf]

I'm with the applianceman, it looks like a thermistor problem.

[applianceman18007260692]

In the photo i don't even see your thermistor. I worked on one once where there was small children around. Somebody had yanked the thermistor right off the window unit

[jb8103]

What are you pointing at in the second photo?

[Bobice]

Let's ask a dumb question ? Are you running the unit @ maximum cooling with the fan on low ? This is definately an airflow issue.