Tumble dryer conked out

[Cursitor Doom]

Hi all,

I have a relatively modern (2003) Hotpoint Aquarius tumble dryer which has given good service for years up until recently. The problem began with it stopping part-way during a drying operation and just sitting there, imobile, making a gentle purring noise. As the problem has got worse, it no longer runs at all and now just sits there purring right from switch-on. I'm going to have to investigate the internals, it seems. What's the most likely cause, statistically, of the trouble and what checks can I perform with the usual DIY meters and whatnot?

cheers, cd.

[Gazz]

Are you missing a cat?

[Cursitor Doom]

Er, no. BTW, I've just discovered it's a condensing 1997 model if that makes any difference...

[newshound]

Sounds to me like the belt has broken, ten years is about the right life if it gets a reasonable amount of use. Normally fairly easy to find spares, replacement a bit fiddly but not too difficult.

[Harry Bloomfield]

Cursitor Doom explained :

Most likely failed capacitors on the main PCB, if the deterioration has been gradual.

[F]

is a more than useful resource.

[meow2222]

When you've had a look you can tell us.

NT

[Cursitor Doom]

I've got most of the casing off now so can have a much better gander at the innards. The belt's fine and the motor and drum turn freely. Well they do now since I removed about two and a half carrier bag fulls of fluff from the workings!

[Cursitor Doom]

Could certainly be. Once I'd got the top lid off I was able to see that a component across the mains input had failed spectacularly with a lot of charring around it in the immediate area. It appears to be a high pass filter from its markings, although I'm not sure wtf one of those would be doing in a tumble dryer. Whatever it is it failed open, btw. I've cut it out and remade the surrounding charred connections and now there's a ticking noise in addition to the purring and a relay somewhere is clicking reasurringly. Still no joy on seeing any action from the heater or motor, though, so I'm wondering if the failure of the device across the input may have damaged something further down the line...

[Cursitor Doom]

Ta for that, F. I'll take a butcher's later.

[Harry Bloomfield]

That is a mains filter.

I was thinking failed electrolytics, on the main PCB.

[Cursitor Doom]

Sussed it! The purring noise was the clue. After all the fluff was out of the way I could see a tiny nylon cog vibrating. I guessed it was not making sufficient contact with another which was concealed, so pressed it back into mesh. The drum fired up immediately, covering me with yet more fluff, given the thing is now so exposed. So, I'm guessing it's not worth messing about trying to repair this part so I'll have to order a new one. Seems to be some kind of timer judging by the ticking noise, but it's right on the floor of the machine, whereas the timer knob itself is right up on the top face panel. Can anyone tell me what this clock-like device is? cheers, cd.

[newshound]

+1.

There is normally a thermal cutout to kill the heater if the motor and fan stop, there is often also a thermal fuse hidden in the wiring somewhere. So if there is still no power to the heater when you get the motor going, look for the thermal fuse. (Also, thermal cutouts seem to fail after five or ten years).

[Harry Bloomfield]

Some heaters also have a thermal trip, many of which are designed so you cannot reset them. However if a tiny hole is drilled where the reset button ought to be, you can reset them with a suitable implement.

[Geo]

That'll be the warranty timer - usually well hidden...

[Cursitor Doom]

Oh it's well hidden alright. Buried beneath the motor and the drum. Never heard of a warranty timer, though, and a quick search throws up no hits...

[Adrian]

It's the widget that's designed to cause the dryer to break down a week after the warranty runs out...

[Cursitor Doom]

Why on earth would they do that? If I find any old nonsense like that in this machine I'll just bypass it/ them.

[Brian Gaff]

Sometimes brushes as well

Brian

[Harry Bloomfield]

Obviously, to attempt to force you to buy a replacement trip. The OEM part cost £35. The same part from other sources £10, but with a reset hole in the centre. Inside is just a bi-metal disk, which pops the wrong way when it overheats. In between the terminals of the OEM item is tiny mark, where the hole would normally be. Carefully drill a 2 or

3mm hole, then push a paperclip in, to reset the trip - cost just your time and once drilled, you can reset it over and over, as the part is designed to be.