Expert Heater not blowing HOT, just tepid. Help please

joyfulnosaj · Post by **joyfulnosaj** » 28 Nov 2010, 21:14

I have just changed from 2000 V reg 1.9td Dispatch van (like Expert) to 2002 (52) 2.0 HDI.

So far everything is ok except the heater.

On the older van the heater blows really hot, very nice and cosy.

On the new van the heater barely warms up. The fan works ok and the dashboard controls seem to work (different directions/fan speed/hot-cold).

Is there some sort of control/thermostat on the engine side that could be afffecting this as it is not much fun at the moment.

Any help much appreciated

Homer · Post by **Homer** » 28 Nov 2010, 23:55

Normally I would suggest the thermostat is stuck open. If so the engine will also run very cool.

But since it's a HDi I'll say it's normal. They supposedly produce very little waste heat to use for the heater.

dieselnutjob · Post by **dieselnutjob** » 29 Nov 2010, 10:14

the HDIs do take a while to warm up but they get there in the end.

Take the van for a drive and then stop. Leave it running stationary so that no air is coming through the radiator. Turn of AC (if it has it) so that the cooling fan stays off.

See how hot the heater gets.

Now go for a drive on a fast road so that air gets pushed through the radiator.

If the engine starts to go cold then it means the thermostat is stuck open.

If the engine is actually hot but the heater isn't then you have a problem with the heater itself such as an airlock. There are a number of different bleed screws in the system and if coolant is drained and refilled without bleeding air out in the right places you can get air in the heater matrix instead of hot water.

joyfulnosaj · Post by **joyfulnosaj** » 29 Nov 2010, 23:57

I have tried the wait and see/touch test.

The into the cabin pipe slowly warms up. The return hose to the radiator stays cold for ages and then slowly warms up, but never gets very hot.

I think I have to face it that I was spoilt with the heat in the 1.9TD and the extra efficiency of the HDI means that it just will never get hot.

Ho Hum. Just think of the better mpg and wear thick socks.

Thank you all for your very useful tips and feedback. I now have a speedo problem and will post separately.

citronut · Post by **citronut** » 30 Nov 2010, 07:45

i have not had much to do with HDI's but im sure they must heat up if all is running well/corectly,

and i would have thought the cabin/heater should heat up faster than the rest of the system,

do you also feel you are getting strong blow throught the heater vents with the fan switched on,

if not check the pollen filter,

were abouts are you

regards malcolm

dieselnutjob · Post by **dieselnutjob** » 30 Nov 2010, 10:14

the HDI might not produce as much heat as the old XUD but it does produce some, and the heat has to go somewhere!
As I said, if the vehicle is stationary and the cooling fan is off, it will warm up even if the thermostat is kippered.
Try it.

Post by **myglaren** » 30 Nov 2010, 22:45

Please refer to the similar thread here

Locking this thread.