Zanussi TC470 tumble dryer is not drying

Re: Zanussi TC470 tumble dryer is not drying

Thanks Martin for the quick reply.

I suspect the thermostat. My wife said that it seemed to be exhausting air that was hotter than normal a few days before it died.

Is there only the one thermostat and do you know if it’s easy to get at?

I’ve got the unit out in the middle of the floor today so I can get started on further diagnosis.

Re: Zanussi TC470 tumble dryer is not drying

Hi Martin –

Well, here is what I found: (Sorry, in advance, for the length… )

First, there was loads of fluff. I hoovered out as much as I could find.

I made notes of everything as I went so I could reassemble later. I noticed that the green belt that drives the fan was lying on the floor, but I thought it was due to the way I took it apart.

I found the exhaust thermostat in the door and got it out. Without a multimeter, I decided that if I connected the two thermostat wires I could simulate a thermostat with a resisitance of 0. Hence the heater should come on.

I hooked up all the wires but left the drum and back panel off. Then I connected up to the mains and – being very careful not to touch any wires – closed the door switch.

Result was – no heat from heater. Since the exhaust thermostat wasn’t in the system anymore it either wasn’t the problem, the heater was broken or I had things hooked up wrong.

Next I looked at the heater and tried to figure out where the wires to it went. My goal was to figure out how I could test the heater cirucits for continuity. While doing this, I noticed a couple of wires disappearing off behind the heater. I took off the heater and discovered that these wires went to a couple of little round things on the back of the heater.

These things looked like thermostats as well and one had a little post sticking out of it. I remembered reading about reset buttons on thermostats so I touched it and heard it go click. At this point I thought I had broken it. However, when I now tested the system, the heater lighted up right away. Then I put the exhaust heater thermostat back in the system and retested. Again, the heater worked. So the problem seems to have been an overheated heater thermostat.

Remembering that I found the fan belt on the floor, I suddenly wondered if it had come off, then the heater had over heated because there was no air flow through it and one of the heater thermostats popped.

Anyway, I put it all back together again and noticed that the heater fan belt went on rather loosely. It wobbled a bit while running but didn’t fall off. So I tried to dry a load of clothes I had just washed. It worked on the high heat program for about 90 minutes.

So I think I’ve fixed it – at least for now.

I’ve also cleaned all the fluff out of the condenser – there was loads! And still to go is the door cavity. The filter is usually keep cleaned, but the door cavity is seriously choked. All the fluff in the door cavity may be slowing air flow and also causing the heater to overheat.

I think I might order a new fan belt (and a few other things I found that could use replacing), but otherwise I’ll leave it alone.

Cheers for now, —————– DocB

Re: Zanussi TC470 tumble dryer is not drying

Thanks Penguin.

I’m away from home at the moment, but I’ll get on it when I return.

The present belt is green. Are they still that colour? I watched it driving the fan for a while (unplugged the heater so that it wouldn’t overheat again) and the bit that is NOT in contact with the rubbing pad seemed to vibrate alot while the drum was rotating forward. When the drum reversed direction, it stopped vibrating. Is this vibration normal? I’m thinking not, which is why I think it should be replaced. Maybe it as lost some of it’s elasticity with age.

Cheers for now.

Re: Zanussi TC470 tumble dryer is not drying

Well – I did have to get the dictionary out to spell “elasticity” . . . :rolls:

Re: Zanussi TC470 tumble dryer is not drying

Trilobite:

Thanks for that info. Mine is the “figure of 8” version. I didn’t know it came in another (1 or 2) flavour(s). So I didn’t say anything about it.

I got a part number for the belt from Penguin45. A quick look for it on the internet indicated to me that it was the same as what I have now.

Penguin45:

You’re right about the age. It is too old to be going down the route of putting another mod on it. We got it in about 1996 or so. Good going for something that old. I understand the Zanussi build quality isn’t that good any more, unfortunately.

This “breakdown” was my warning call, I think. I’ve started looking for a replacement and am interested in a Miele or AEG probably.

Everyone Reading:

If ever you do delve into the innerds of your dryer, have a hoover handy. Mine was absolutely chocked with fluff. I hoovered out around the motor, around the back panel and everywhere else I could stick the thin nozzle of the hoover attachment into. I also took the opportunity to put a little light duty oil on the drum shaft bearing. I was going to put a little wheel bearing grease on it, but that was in the garage and it was a dark and stormy night :rolls: .

In addition, the air circulates via a channel in the door through a fluff filter. We always cleaned the filter between dryings, however the channel gets clogged as well. This was probably the main reason for the fault I had (heater thermostat had tripped). The channel was so clogged that air flow was restricted. I think that may have restricted air flow over the heater element thus causing it to over heat.

Cheers to all, ————– Doc

Re: Zanussi TC470 tumble dryer is not drying

Hi Trilobite:

I like the idea of using an old duster. What I noticed on my door was that the dust or fluff had actually “baked” on. I had to scrape it off with a paint scraper. Sounds gross – it was!

More routine maintenance would probably clear it before it had a chance to harden.

On another subject: I found some blown up parts diagrams for this dryer. One part was listed as a “Drum Mill.” Looks like something that the drum rubs against as it rotates. It isn’t on my dryer. Do you know if that is a problem?

Any other “routine” consumables I should replace while I’m at it?

Cheers, ———– Doc