Xantia series I Heater Problem

citronut · Post by **citronut** » 17 Dec 2010, 19:18

hi Grumpyme and welcome

have you checked your pollen filter is not blocked as i belive this can/will stop air flow through the heater/matrix,

as you say both your heater hoses are hot,

regards malcolm

Grumpyme · Post by **Grumpyme** » 21 Dec 2010, 08:34

Thanks Malcolm

I took your advice, the pollen filter had been changed earlier this year but I took it out - not much change in the heater output, still just warm.

There is mention in the previous posts about heater control flaps, but my heater control is marked blue, 18, 22, 26 red which makes me think that there may be some form of thermostatic control somewhere.

The Haynes manual is vague about the heater

Does anyone have any ideas?

hobblerian · Post by **hobblerian** » 21 Dec 2010, 11:24

MJM wrote:I have noticed that the heater in mine hasn't been as good as usual. I have also noticed that the engine temperature has been lower. Traffic on my local roads has been moving slower as well. I have come to the conclusion that the heater matrix, and internal fan, in the prevalent low ambient (-5 this morning) and slow speed is more than capable of doing all the work of cooling the engine. I doubt if the thermostat is getting hot enough to open normally.

There may be a bit of unnecessary matrix panic setting in.

It should take longer to warm up but should still reach normal running temperature. Yours could be a stuck open thermostat, does the rad slowly get warm as the engine warms up?

hobblerian · Post by **hobblerian** » 21 Dec 2010, 11:33

Grumpyme wrote:Thanks Malcolm

I took your advice, the pollen filter had been changed earlier this year but I took it out - not much change in the heater output, still just warm.

There is mention in the previous posts about heater control flaps, but my heater control is marked blue, 18, 22, 26 red which makes me think that there may be some form of thermostatic control somewhere.

The Haynes manual is vague about the heater

Does anyone have any ideas?

Does the Xantia have a cabin temperature monitor like the the XM? Mine sits in the front interior light fitting with a fan drawing the air through the sensor. This tells the heater system how much hot/cold air to maintain temperature set on heater controls.

Grumpyme · Post by **Grumpyme** » 21 Dec 2010, 13:27

Yes, I have just discovered the cabin temperature monitor from another thread. The fan only runs when the engine is running, have given the monitor/fan a spray of contact cleaner and will see how things go tonight.

MJM · Post by **MJM** » 21 Dec 2010, 20:45

Hobblerian,
>>it should take longer to warm up but should still reach normal running temperature. Yours could be a stuck open thermostat, does the rad slowly get warm as the engine warms up<<

It warms up ok, the thermostat is working properly, I just get the impression that the heater is dispersing a lot of heat which would normally be shed by the radiator. I like being toasty warm in the car

Warming the incoming air from -5 to MJM's idea of warm takes a lot of heat. A decent run down the motorway (the engine purrs at 4000rpm) sees the water and oil temperatures up to their usual level.