Dehumidifier frosting up

ctomas

Meaco dehumifier used in house temp on nest min 19deg, has started creating ice inside and tripping the electrics. Any ideas what’s the problem? Initially thought it was that i hadn’t cleaned the filter in a while so done they but happened again.

here it is opened up. Iced up on top section here. Setting at 50%rh

DC999

https://www.boards.ie/discussion/2058330287/dehumidifier-frosting-up

Won’t pretend to know. I’ve a Meaco too and has worked for 8 years and still going. I’ve seen aircon units do that (in an office I worked in before) and every time it was down to a leak so the refrigerant gas has escaped.

 The tripping is more important than the ice. Does it work on the air purifier and not trip it? That only draws like 50watts or something. That will only tell you if it’s working to any extent. It won’t freeze on that as it’s not dehumidifying of course.

 As you know, the compressor model doesn’t like running in a cold room. When you say the thermostat on the Nest is set at 19deg min, is the room actually at that temp or higher? Afaik mine does the defrost cycle around a room temp of 17C. As in have you tried it in a warmed room to see? That’s not going to explain it tripping though.

 

McHardcore

Is the fan running? Maybe its stopped, leading to the fins getting too cold.

Tow

I have seen icing happening were the thermostat probe on the fins had moved slightly. This caused the system not know the actual heat exchanger's temperature allowing it to get frosted up.

ctomas

Thanks for the reply.

Sorry, I should say that the unit trips after a few hours - at the point the ice builds up.

the room is always warmer than 19c it’s in the centre of the house and a warm area.

10-10-20

Sounds like the evap coil stat to me. The refrigerant/evap coil gets overdriven and ices-up if the stat is faulty and can't detect that it's running too cold. Once it finally cycles off then the residual heat off the compressor then melts the ice down on the wiring and it trips the RCD.

Find the stat on the evap coil and see if it's replaceable?

ted1

Probably a fault with a temperature sensor. They are meant to shutdown just before the build up of ice.

ctomas

Okay, thanks all so far!

I think I found the thermostat and appears to have some corrosions so cleaned up the two surfaces and now going to test it.

only problem is that the humidity is so low these days, it’s going to be hard to test!

DC999

https://www.boards.ie/discussion/comment/121595750#Comment_121595750

Hang wet clothes in the room. Put towels in a bucket of water. Boil a kettle in the room with the lid open. It will keep running - stay in the room for safety of course!

Tow

If the cleaning does not work and assuming the thermostat is working, you can also try moving it nearer to the area icing up. In my case the top of the heat exchanger was icing up