QHM06LX Haier Window AC frozen on the top part of the evaporator

[jazzwineman]

Model Number

QHM06LX

Brand

GE

Age

Less than 1 year

This is the second Haier 6000 BTU (QHM06LX) unit I have gotten. I use this for zone cooling in my window near the kitchen and dining area as I do have Central air, but those areas are the furthest from the Central AC.

The first one lasted 2 summers and then started to freeze up at all temperatures. Either it developed a leak from nowhere or there was some internal mechanical problem. I clean the filter every week, keep the evaporator fins clean as well as the condenser fins. In winter I put a protective cover over the whole outside part as I do a more more robust install or weather and bugs would get around the unit with the windows I have. I regularly use coil cleaner on the condenser coils. There is zero problem with airflow at any location in the AC.

So I bought last summer another one just the same as before. Did my same robust install and then this winter kept it covered again.
Started it at the beginning of summer here in Texas and everything worked fine. Since I get the west sun in the afternoon in that area and I run it at high and set at 64 so that is runs al the time.

The other day it was 99. i was gone for about 70 minutes and came in and found it frozen on the top part of the evaporator and in the unit the suction filter and line to the compressor was covered in ice. It was a simple procedure in hot temps to unfreeze. I had cleaned the filter the night before and the evaporator coils/fins look brand new.
I then unplugged the unit, got my coil cleaner, sprayed it on the condenser coils/fins, let it do it's work and then hosed it off well and cleaned up the tray where bugs or pieces of leaves sometimes fall.

Started it up and all seemed to work well for the rest of Wed, Thursday and Friday.
Then Saturday in the middle of the afternoon with the temp at 99 degrees the same freeze up. The unit is clean, the coils and fins are clean, the front blower blades are clean, the condenser fan is 90% clean. Clearly there is either a malfunction of some sort or a coolant leak has come about from nowhere. It seems to operate in the defined specifications and the air coming out of the vents is about what I would expect using my IR temp monitor. Today I set it at 70 and left for about 90 minutes and it was starting to freeze again when I got back. Now if I turn it on and the condenser comes on, then 2 or 3 of the copper pipes going to the evaporator want to frost up quickly.
Apparently there is a serious reliability problem with these units and there seems to be no valid reason for it to freeze up being this new.

The only thing I might mention is that one of the vents of the Central Ac us nearby and may lower the temp of the air going over the evaporator coils. Could that be a problem?

Does anyone have a suggestion as to what could be the problem if not the machine. I have run it allowing water to drip and run it with the plug in for water to hit one the condenser coils. Would that make a difference.

Any help is highly appreciated.

Thanks

Tom in Dallas/Plano

 

[Dan O.]

If it was low on refrigerant it would stop cooling the last part of the evaporator and never freeze past it to the tubing to the compressor.

If the inside air isn't too cool (which would cause freezing of the evaporator), air flow through the evaporator could be responsible. Ensure the fan is operating at full speed and also it's blades are clean.

Otherwise, I don't know about your model but we have previously encountered imported units that had very dense fins on the evaporator coil and when they got sweating, we assumed it limited air flow through the coils (like waterboarding) causing a freeze up. We couldn't find any other reason for it.

We could only advise the customer to keep the fan on high speed, try to limit the running of the compressor somewhat to allow the condensation to drain off the evaporator between running and to make sure the A/C is tilted to aid adequate (or increased) drainage.

When you clean it you might want to clean the evaporator coil as well. Even fine particles on the coil could retard drainage from its surface, possibly enough to effect air flow through it when it gets sweating a lot (i.e. in humid conditions).

Good luck!


Dan O.

 

[jazzwineman]

Thanks. I have indeed cleaned the evaporator coils with some coil clean and a toothbrush and small coil cleaning brush, but got next to nothing and they are blue and look brand new. Does the fact that it seems to freeze at the top of the evaporator coils and not the bottom tell you that is has a Freon leak or would that be normal and I just get to it before it has a chance to freeze all the way. There is an ac vent within 15 inches of the window unit. Could that cause the air going into the coils to be too cold. I put my IR temp reader on the front of the unit and the air going in was at 63-64 degrees. I always keep it on high speed. It has never been lower. I can reach the fan when the front is off and cleaned all of them, but they were only slightly dirty in certain spots and not sure if it affected the speed.

Thanks

Tom

 

[Dan O.]

Does the fact that it seems to freeze at the top of the evaporator coils and not the bottom tell you that is has a Freon leak

It depends on how gas is fed through the evaporator. Usually the refrigerant enters the bottom passes of the evaporator first and exits at the top of the evaporator and then onto the compressor. If yours is different ...

Anywhere frost is accumulating means there IS refrigerant there. Loss of refrigerant = less of the evaporator cooling. See the paragraph above as to where that would be noticed first.

There is an ac vent within 15 inches of the window unit. Could that cause the air going into the coils to be too cold. I put my IR temp reader on the front of the unit and the air going in was at 63-64 degrees.

It might. The colder the air entering the evaporator, the less evaporation of the refrigerant takes place. That refrigerant will then travel to the further parts of the evaporator and possibly continue to the tubing to the compressor.

There are 'scoops' you can buy for furnace ducts to direct the exiting air. Maybe try one of those to stop the cold air from being sucked right into the A/C.



Try turning the a/c thermostat back a bit to allow the compressor to cycle a bit and not run continually.

Dan O.

 

[jazzwineman]

Thanks. Worth a try.

What do you think of room AC's?

TBB

 

[Dan O.]

What do you think of room AC's?

*By "room A/C" I assume you mean "window A/C" as they are designed to cool a single room.

I've never had any problems with them. They're certainly better than portable models.


*If you mean some other type of unit, please be specific.

* Edited Aug.12, 2021

Dan O.