A/C Forming Ice. How Could I Repair It?

[Will2011]

Hi,

A couple of days ago, my a/c unit (mitsubishi) started to form ice inside the unit right after turning off the a/c. Now it's doing it like every day with a very loud sound. I tried to read the manual that comes with the unit, but I hardly understand Thai...

Any ideas on how to fix that before it explodes my entire bedroom?!

Thanks

[farang000999]

how about hire a thai to fix it for a pittance?

[Upnotover]

Probably just needs cleaning, lots of AC cleaning people about (depending on where you are that is).

[Will2011]

To hire anyone, if I need it to, I have to find out the root of the problem, so that I pretty much know what I'm dealing with.

is there a filter or something to change?

[Upnotover]

To hire anyone, if I need it to, I have to find out the root of the problem, so that I pretty much know what I'm dealing with.

is there a filter or something to change?

google "ac icing" and you find lots of advice, but most likely a 300 baht clean will do it.

[mogandave]

There should be a panel that pops out easily and once open the filter should slide out easily. Remember how it comes out as it goes back in the same way. To clean it, just rinse it out with a hand held shower. Use hot water is you have it. I can do mine easily in less than ten minutes. If you use the air quite a bit you should clean the filter regularly. I do the office every month and the house every few months.

If that does not help it is probably leaking refrigerant. Once the refrigerant gets low, it will start freezing up. You can have it recharged, but if the technician does not find and fix the leak this will only be a temporary fix. Sometimes the charge will last a year and sometimes just a few weeks.

How old is the unit?

[Semper]

Try posting in the diy housing forum, I bet you get better answers there.

[Naam]

A couple of days ago, my a/c unit (mitsubishi) started to form ice inside the unit right after turning off the a/c.

ice does and cannot form after turning the unit off! common cause of forming ice is lack of refrigerant. top up, problem solved.

[arkom]

I had similar problem with my a/c, had it cleaned and problem gone.

[angiud]

Call a technician.

Happen when a unit lack/wrong maintenance and proper cleaning

[Naam]

I had similar problem with my a/c, had it cleaned and problem gone.

no fairy tales please. cleaning does not stop forming ice. most probably the unit was cleaned and its refrigerant topped up. that's normally done when you call a contractor.

only in very rare cases when the filter is so dirty that airflow is extremely reduced ice can form. but that also means that the filter has not been cleaned for years (which is highly unlkely).

[Will2011]

Thanks guys, i'll try your suggestions and i'll let you know

[Will2011]

There should be a panel that pops out easily and once open the filter should slide out easily. Remember how it comes out as it goes back in the same way. To clean it, just rinse it out with a hand held shower. Use hot water is you have it. I can do mine easily in less than ten minutes. If you use the air quite a bit you should clean the filter regularly. I do the office every month and the house every few months.

If that does not help it is probably leaking refrigerant. Once the refrigerant gets low, it will start freezing up. You can have it recharged, but if the technician does not find and fix the leak this will only be a temporary fix. Sometimes the charge will last a year and sometimes just a few weeks.

How old is the unit?

The unit is 1yo. I popped out the cover but the filter seems to be fine. However, there's a metal grid beneath the filter and I can see that the top of it is all frozen with ice.

So it means that i have to top up with gas, doesn't it?

[Naam]

The unit is 1yo. I popped out the cover but the filter seems to be fine. However, there's a metal grid beneath the filter and I can see that the top of it is all frozen with ice.

So it means that i have to top up with gas, doesn't it?

the "metal grid" is the evaporator on which ice forms when refrigerant is mission or airflow is very lo. and YES have the unit topped up. not with "gas" but with liquid refrigerant

[Tywais]

and YES have the unit topped up. not with "gas" but with liquid refrigerant

Tell a Thai to fill it up with 'liquid refrigerant' and he's just going to stair at you in bewilderment - say 'gas mort' and bingo.

[Naam]

and YES have the unit topped up. not with "gas" but with liquid refrigerant

Tell a Thai to fill it up with 'liquid refrigerant' and he's just going to stair at you in bewilderment - say 'gas mort' and bingo.

they may say gas but they know that the bottle has to be turned upside down that liquid is sucked because otherwise it takes ages to top up

[Tywais]

and YES have the unit topped up. not with "gas" but with liquid refrigerant

Tell a Thai to fill it up with 'liquid refrigerant' and he's just going to stair at you in bewilderment - say 'gas mort' and bingo.

they may say gas but they know that the bottle has to be turned upside down that liquid is sucked because otherwise it takes ages to top up

Funny enough, I've watched them in the US turn the refrigerant bottle upside down but the many times I've seen Thai technicians recharge have yet to see one that does it.

[mogandave]

There should be a panel that pops out easily and once open the filter should slide out easily. Remember how it comes out as it goes back in the same way. To clean it, just rinse it out with a hand held shower. Use hot water is you have it. I can do mine easily in less than ten minutes. If you use the air quite a bit you should clean the filter regularly. I do the office every month and the house every few months.

If that does not help it is probably leaking refrigerant. Once the refrigerant gets low, it will start freezing up. You can have it recharged, but if the technician does not find and fix the leak this will only be a temporary fix. Sometimes the charge will last a year and sometimes just a few weeks.

How old is the unit?

The unit is 1yo. I popped out the cover but the filter seems to be fine. However, there's a metal grid beneath the filter and I can see that the top of it is all frozen with ice.

So it means that i have to top up with gas, doesn't it?

If it has to be topped off, it’s leaking. The leak needs to be found, or this will be on ongoing issue. Some guys don’t mind having someone come into their home and make a mess every several months, I do.

Installed correctly, the AC should work indefinitely without any service beyond cleaning the filter.

The mitsu is one of the best mini-splits out there, and if it is only a year old it could well still be under warranty.

[Naam]

and YES have the unit topped up. not with "gas" but with liquid refrigerant

Tell a Thai to fill it up with 'liquid refrigerant' and he's just going to stair at you in bewilderment - say 'gas mort' and bingo.

they may say gas but they know that the bottle has to be turned upside down that liquid is sucked because otherwise it takes ages to top up

Funny enough, I've watched them in the US turn the refrigerant bottle upside down but the many times I've seen Thai technicians recharge have yet to see one that does it.

i have to admit that i had to show it to the first "technicians" who cleaned and topped up some of the units. in the meantime i found a subcontractor whom i don't have to tell how to do his job. what still drives me crazy that there are leaks. in another home we have units which were installed in 1993 and never leaked in nearly two decades. one of the problems (caused by shoddy hard soldering) is that the couplings which are used in more "advanced" countries are bloody expensive in Thailand, therefore nobody uses them. not using couplings requires direct soldering of unit pipes to the laid pipes which is quite difficult. but that's were the leaks are or develop over time.

another reason is that solder sticks containing 30% silver, which were used in olden times, are financially out of reach.

[Pib]

Low on freon or the inside unit "coils/fins" are very dirty on the surface and/or withing the coils/fins. I guess it's possible for a really dirty filter to cause the problem but usually it's really dirty coils/fins...dirty coils/fins caused by not cleaning the filter often enough and/or a dirty/oily environment which will accelerate the problem of the coils/fins/filter getting dirty. When the coils/fins are really dirty(partially blocked) little airflow occurs through the coils/fins which basically allows the coils/fins to reach the freezing point and humidity/water will start freezing between/on the coils/fins blocking the air flow even more which just magnifies the freezing problem. Once the coils/fins are frooze-up pretty good and the unit/fan is still running the warm air hitting the ice sheet will start to melt the ice which usually produces enough water to overflow/overpower the water drain tray under the coils/fins which connects to the drain tube. When people don't feel the unit cooling due to the blocked/frooze-up coils/fins they many times turn off the unit and this will cause the ice to start melting and therefore people think there is a water leak when the unit is turned off. A good cleaning of the coils/fins may fix your problem. Low freon can also cause the same problem.

Edited August 16, 2012 by Pib

[Naam]

If it has to be topped off, it’s leaking. The leak needs to be found, or this will be on ongoing issue. Some guys don’t mind having someone come into their home and make a mess every several months, I do.

Installed correctly, the AC should work indefinitely without any service beyond cleaning the filter.

The mitsu is one of the best mini-splits out there, and if it is only a year old it could well still be under warranty.

right you are, but finding the leak is a problem especially if there are soldering points of a pipe which is under plaster in a wall.

cleaning just the filter is insufficient. watch the pitch black gravy which is the result of a thorough cleaning of evaporator and squirrel cage fan professionally done by foam. and that should be done every 2-3 years even when the units (as in my home) are fitted with electrostatic filters which are cleaned once a month.

by the way, perhaps i am lucky with my contractor, but there is no mess at all. they know their job.

[Pib]

When cleaning the evaporator with a foam type cleaner be sure to spray it on is such a way that the cleansing agent gets deep into the coils/fins before it starts foaming; just shooting it in such a way that the foaming action primary occurs on the top service of the coils/fins won't get the dirt & grim deeper into the coils/fins which are probably 1 to 2 inches in thickness. And be sure to rinse the foam well to rinse away the dirt/grim. A person can usually find foaming type A/C cleaners at places like Big C, Amorn, HomePro, etc., type stores. Amorn Electronic Stores also usually sells a cleansing agent called Smile F11 which is a clear A/C degreasing liquid and smells similar to fingernail polish remover. It costs about 70 baht per bottle (about the size of small beer bottle...I bought some just a week ago). Do a 50-50 mix with water in a spray bottle, and spray down the evaporator coils/fins real good....spray it on is such a way to avoid getting it on your wall, curtains, or anything else around the A/C. Let it set/work for about 5 minutes and then fill up that spray bottle with water and spray the coils/fins to rinse out the cleansing agent/dirt/grim. The drain tray at the bottom of the coils/fins should catch most of the drainage but putting an old towel/rag underneath the A/C to catch any that overflows is probably a good idea to protect anything like curtains, wallpaper, etc., under the A/C. Most any strong household cleanser can also be used...it really doesn't have to be anything special just for A/Cs although A/C cleansing agents are usually stronger than the average household cleaner.

Edited August 16, 2012 by Pib

[Sateev]

and YES have the unit topped up. not with "gas" but with liquid refrigerant

Tell a Thai to fill it up with 'liquid refrigerant' and he's just going to stair at you in bewilderment - say 'gas mort' and bingo.

they may say gas but they know that the bottle has to be turned upside down that liquid is sucked because otherwise it takes ages to top up

Funny enough, I've watched them in the US turn the refrigerant bottle upside down but the many times I've seen Thai technicians recharge have yet to see one that does it.

Refrigerant gas cylinders have siphon tubes, and should NOT be inverted or laid on their side when charging. You want LIQUID, not GAS. Even Rainman knows this.

[trogers]

I am surprised no one asked if there is smoking in this air-con room. Tar deposited on the coil/fins speeds the accummulation of dust/dirt and can cause icing.

Chemical cleaning of the coil/fins will be required to rid the tar.

Edited August 19, 2012 by trogers

[Pib]

Dogs/cats can cause a faster build-up on the coils/fins also as they are always shedding with fine hairs/particles finding their way in the room air circulation to the air con...and the filter don't stop all of them....I should know as the wife and I have 4 dogs. Years back when I lived in the States in my central air home, after about 8 years my York central air unit/evaporator started freezing-up/causing melting ice/water on the floor/etc. Freon pressure checks were good...but the evaporator would still ice over under the right temperature and humidity conditions. I had always changed/cleaned the filter approx every month, but after X-years stuff gets past the filter and finally clogged up the evaporator coils/fins. The coils/fins looked clean on the surface but you could tell when trying to shine a flashlight through them that light just wasn't getting through. I cleaned it with some foaming type cleanser and there was plenty of gunk/fine hair that was pushed out/cleaned by the foam. And when doing the flashlight test again, light would shine through. This cleaning fixed my evaporator icing problem.

[Stefanix]

Had the same problem recently on one of those cheapos from York. The reason was that the compressor outside was working permanently with full power, instead of being turned off as soon as the desired temperature is reached. So the indoor heat exchanger was cooled to the maximum, but this could not be distributed to the room. Same effect, ice eventhough the a/c was turned off with the remote. The cause was actually the control board inside the indoor unit. I am still waiting for the replacement. In the mean time I swapped the controller board with another one from a room we don't use so often.

[Naam]

Refrigerant gas cylinders have siphon tubes, and should NOT be inverted or laid on their side when charging. You want LIQUID, not GAS. Even Rainman knows this.

perhaps in your country, but not in Thailand.

[Will2011]

how about hire a thai to fix it for a pittance?

Alright. The company I contracted (as I wasn't able to do it myself) just left right now. They diagnosed that the A/c units were dirty. So they cleaned both units with high pressurized water machine and the two things outside. They also added refrigerant.

Total Damage: 1,200 BATHS + FREE DIRT ON THE WHITE WALLS! Cleaning was 800 B for both, and Refrigerant 400 B (20 B /lbs)

I feel like I was ripped off... What do you think?

[Naam]

how about hire a thai to fix it for a pittance?

Alright. The company I contracted (as I wasn't able to do it myself) just left right now. They diagnosed that the A/c units were dirty. So they cleaned both units with high pressurized water machine and the two things outside. They also added refrigerant.

Total Damage: 1,200 BATHS + FREE DIRT ON THE WHITE WALLS! Cleaning was 800 B for both, and Refrigerant 400 B (20 B /lbs)

I feel like I was ripped off... What do you think?

except for the dirt on the wall it was a fair price even though the price for refrigerant is much higher than you quoted. both your aircons couldn't have taken 20lbs as you claim.

i pay 400 Baht for a thorough cleaning but i always have at least 6-8 units to clean. and of course there's no dirt on the wall or the floor.

[Will2011]

So, i've been ripped off on the refrigerant. How many pounds do a/c units usually take?

Well, $45 for Thailand, I think it's quite a lot. If they have like 10 clients per day, they make good money. Who wants to become an a/c expert?