Hotpoint CTD85A thermostat and thermistor(s) help

[HOLLYWOOD]

Hi,

First time posting here so apologies if I’ve got anything wrong in terms of forum etiquette. I also apologise for the long post – I just want to be thorough.

In November last year, my condenser dryer stopped working. It threw up error codes f-08 and occasionally f-10 on the LCD display. The dryer basically stopped heating up and would keep stop/starting on every cycle.

Ive always ensured I emptied the water and cleaned the filter prior to every use. I must admit I only cleaned the condenser maybe twice a year but it was always pretty clear anyway.

However, took the top and sides off to Hoover out the fluff inside and also checked out the heater element – I noticed the element itself was damp and was corroded. One of the elements wasn’t even connected due to corrosion!

I ordered a replacement from hotpoint which came complete with the two thermostats and thermistor – I fitted it and it ran fine for a few days then it threw up the f-08 code frequently.

It’s been like this ever since. I select a cycle, it starts fine, runs for about 15 mins, stops, adjusts the remaining time to dry, then it continues to run.

However, it always stops/starts every few minutes, it runs for 30 seconds or so (sometimes longer) then it stops for a few minutes (sometimes shorter/longer) yet the countdown timer on the display reduces accordingly.

It seems to get stuck on the last 10 mins everyt single time – I deliberately leave it to keep going until the machine beeps and showed f-08 and I have to turn it off at the wall.

I’ve tried resetting the thermostat so many time but makes no difference (it has never clicked when I push a pin inside the hole) – the element looks fine this time too although there is evidence of moisture at the bottom and around the bulged metal backplate/cover.

I bought a basic multimeter to test the two thermostats, they both show continuity so I assume they’re fine? – never removed the thermostats to test them – I just unplugged the connectors – is that OK?

I’ve tried to get my head around thermistors (front and rear) too but suspect I don’t fully understand it…

I once again never removed them to test. I set my multimeter to ohms (20k) I touched the probes to confirm the meter works and attached the probes at room temperature on the rear one – the meter just showed “1” which suggests that there is no reading registered. I blew a hairdryer onto the thermistor for about 30 seconds and re-checked but the meter read the same.

I repeated this method on the front thermistor which gave exactly the same results.

I assume both the thermistors are faulty?

By chance, I still had the old heater element I replaced so I tested the thermostats and the thermistor on that one which also did the same…

Any help would be appreciated because I’m tired of trying to polish a turd hahaha

I’ve attached some pictures of the original failed part if that helps?

Cheers!

Hotpoint CTD85A
Serial number – 502010224
Part replaced was “heater (one shot+cyc) C002258828

[kwatt]

Re: Hotpoint CTD85A thermostat and thermistor(s) help

Last ten minutes should be the cool down phase, no heat produced just cool air over it to remove heat from the machine and load.

If it errors out there then I’d suspect the issue wasn’t the heater as it really shouldn’t be in circuit at that point.

The chances of a replacement part with the same fault, so close to zero it is really zero in practicality.

I’d have to think the relays on the board were sticking as I can’t think of any other plausible reason but, I am not that familiar at all with these particular dryers so any of the guys with more experience of them may have another theory or suggestion.

The thermistors are a possibility of course but I’d expect it to error out if it couldn’t read those.

K.

[HOLLYWOOD]

Re: Hotpoint CTD85A thermostat and thermistor(s) help

Hi K,

Thanks for taking the time to reply – appreciate your insight.

The relays you mention, where are they and can they be tested/replaced at all?

Please bear in mind, I only have intermediate skill levels haha

[Allsorts]

Re: Hotpoint CTD85A thermostat and thermistor(s) help

When you say it rotates for about 30 secs and then stops for a few mins.. This is an indication of a faulty motor relay or relay drive on the pcb… The motor gets the power to drive one way but then when trying to switch directions it loses the power feed from the relay and halts for the time of that rotation.

[HOLLYWOOD]

Re: Hotpoint CTD85A thermostat and thermistor(s) help

Cheers Allsorts,

That sounds expensive…

Any way of me being able to check/test?

[Allsorts]

Re: Hotpoint CTD85A thermostat and thermistor(s) help

Not if you don’t know what you are doing. You can contact the company called EMW electronics who repair these boards

[Author]

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