How to repair a Rubydry dehumidifier

[lemel_man]

I purchased a 2nd hand Rubydry DH600 dehumidifier which ran fine for the first two weeks, collecting about 4-5 ltrs/day. Then one morning I found it had stopped with the warning light on and the Mid light flashing. Since the on/off button was inoperative I pulled the mains plug. After re-inserting it I pressed the on/off button and it started running properly again, only to fail a couple of nights later with the same fault. I followed the same procedure and got it working again, but when it happened again the following day, the error was hard. This time I couldn't get it running so I called a company called Dry-it-Out who suggested checking for a blown fuse or that the drum was still rotating. Both were OK so I switched it off until I got some more information.

Several days later I demonstrated the error to a friend but, much to my surprise, it started running properly when I connected the mains lead. Its now been running properly for 48 hours, collecting about 4 ltrs/day on the Mid setting. Can anybody shed any light on this intermittent problem?

[Harry Bloomfield]

lemel_man explained on 19/02/2010 :

Might it have simply shut itself down because it had been especially cold over night?

[js.b1]

I believe they are made/imported by EHS in Manchester. Look at the bottom rear of the unit, you may find a telephone number, if not search online.

They have a full exploded parts-diagram with every part listed, and I believe service facilities.

As you know they do not use a compressor, they use a dessicant disc. Thus should be particularly reliable in that there is very little to go wrong and also very repairable (no compressor). Low temperature is not a problem, they maintain their efficiency unlike many (they kick out about 350-570W heat remember). Only the Mitsubishi unit is more reliable, but frankly at =A3330+ too expensive.

[NT]

Desiccant wheels use around twice as much energy as compressors though. If you dont need low ambient temp operation you might be better off with a compressor machine.

NT

[Mike Lane]

NT wrote on Feb 19, 2010:

Yes that's what I've always thought, but I'd like to see a proper comparison of the extraction rate/kW of energy under identical conditions.

A typical desiccant dehumidifier is quoted as consuming 620W and giving an extraction rate of around 8 litres/day. My compressor unit uses 250W and is quoted as extracting 10 litres/day *but* that is at 32ºC and 80% rh - i.e. unusually high temperature and humidity. Under more normal conditions the extraction rate that I get is far less than 10 litres/day - I would guess around a third or quarter of that0