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Hello. I am looking for some help with how to fix my Bosch WTW87560GB/02 heat pump dryer. I had noticed initially that it had begun to take much longer to dry a load of laundry than before (circa 3-4 hrs). I followed the guidance of other posts here that suggested the condenser/heat exchange being coated in lint, but after taking the entire machine apart to get to the “white box”, I found that it was pretty spotless inside, but gave it a clean anyway.
After re-assembly, it didn’t improve things. But what I did notice was that the ventilation fan on the bottom right doesn’t start during the cycle. Furthermore, about 1-2hrs into the cycle, the compressor stops functioning (overheating?). I can confirm the fan does work though because one or more of the diagnostic modes start the fan, also none of the diagnostic tests fail with an error code.
All of this leads me to conclude that either the NTC is failing, or the main board is failing. I have tested the NTC with a multimeter and it is measuring around 5KΩ at 25°C, but I don’t have the facilities to check the resistance at other temperatures. So at face value, it appears fine, but it’s possible it might be drifting out of spec.
At this stage, I’m at a bit of a loss, and I’m hoping someone can offer other suggestions.
are you sure the condenser is clear and air can flow through it
had a samsung unit the other week which looked clean but had caked lint inside the fins stopping air flow
Dave
Hi Dave. From what I remembered it did look fairly clean, but I could take a look and see if the lint is caked on like you say.
One other thing I failed to mention before was that I took temperature readings of the entry and exit pipes of the condenser and evaporator. Condenser measured 60 in and 35 out. Evaporator measured 5 in and 20 out, so they appear to be dissipating and absorbing heat. Just not sure if those are the measurements to be expected.
no idea of measurements but most of the faults on these dryers are airflow based so that is always the first thing to check
the more the evaporator gets blocked the longer things take to dry
Dave
yes that looks fine
the front part gets cold which is why its corroded. the back half is where the heat goes so thats why it looks good
if the compressor is not doing its job properly then it wont get as cold and takes more time to dry
you need to check if the compressor is running ok and the front plate is getting cold
Dave
That complete unit the condenser and evaporator and compressor is lifted out to clean it out properly and after 20 minutes it should draw a minimum of 350w try running it and a timed warm programme if it doesn’t get up to at least 350w after 20 minutes mo repair is possible
So, a bit of an update. I stripped down the machine again, extracted the condenser/evaporator unit as suggested and gave it a good clean out along with the condensate tray. There wasn’t much in the way of residue and it is now pristine.
Unfortunately, this seems to have no effect. The compressor still stops operating after about 1-2 hrs (generally the amount of time I expect the ventilation fan to kick in). When the compressor is working though, it does seem to do its job. Water is pooling in the condensate tray.
[USER=”49782″]kaibart[/USER] the total power draw from the machine after about half an hour or so is ~600W. When the compressor stops, it drops back down to 200W.
I have to turn the machine off for about 20 minutes for it to cool down a bit when I can then switch it back on again to complete the cycle.
I have really run out of ideas now. Is there anything else that I should be looking for?
i take it the way you are talking is it has to be stopped for 20 mins or it wont start which sounds like an overheat problem
have you tried putting wetter clothes in it when it stops to see if it will restart immediately
Dave
It very much feels like an overheating problem (hence the name of this thread ツ). I’ve tried the wetter clothing suggestion this afternoon and it made no difference unfortunately. I still had to wait for the machine to cool for about 20 mins before resuming the cycle. The ventilation fan still refuses to come on during the cycle.
I have taken the panels off the machine again though to try and observe anything else that might be considered unusual. The compressor is very hot to the touch. Is this normal?
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