(T) heating stuck

Hello,

looks like I ended up at a bad garage. Right after the last service the heating of my little Seicento stopped working. Well, it's still working but the heating doesn't go off anymore. I can only chose between a medium (now standard) and higher temperature I complained at the garage but they claimed to have nothing to do with it, I'll thus have to pay for the repair.

Can I fix the problem myself? How is the heating controll of a Sei constructed? I'm glad about any technical advice

tethys

What did they do at the service?

Do I get you right -- the blower works fine, but you always get hot air?

Yes, I suppose that's what I mean. I cannot switch off the radiator anymore. I can still switch off the blower but then the radiator is still working of course. There must be something wrong with the thermostat.

Tethys

Not the thermostat, but the heater cock, probably. You could try a search on here for "heater cock".

I'd be inclined to leave the job until the spring. It's not a technically difficult job, but a high labour charge one because the heater is buried so deep in the car. Unlike the thermostat, it's a simple valve. I can't see it being connected to the service.

Thanks a lot for your answer. I searched a bit through the forum and found a few un-lady-ly threads on that topic. Might indeed be the valve. What I don't understand: how can a damaged valve keep the radiator on a constant high temperature?

Tethys

The way it should work is that if the valve is closed, then there is no water flow through the heater matrix. The water in the heater matrix soon returns to ambient temperature.

The further open the valve is, the more water flow, the more heat transfer. The same as a domestic central heating system (at least, one where the radiators don't have individual thermostats).

The other possibility -- if the temperature control lever feels very slack -- is that the wire that opens and shuts the cock has just fallen off.