Heaters playing up

Thomo1927 · Oct 28, 2015

My 300 tdi discovery heaters are blowing cool ,Head gasket has been changed. Not loosing any water or overheating. Pipes are very warm but it's blowing cold. Heater matrix blocked maybe or something else.

I know you haven't got a crystal ball but any tips for me ? Cheers

blue beasty · Oct 28, 2015

Trying bleeding and rebleeding at the stat housing valve with the engine ticking over.

Thomo1927 · Oct 28, 2015

blue beasty said:
Trying bleeding and rebleeding at the stat housing valve with the engine ticking over.

I have bb many times ,I can put up with it but my Mrs who is 5 months pregnant is having none of it.Just trying to sort it out myself to save some baby money. Cheers

blue beasty · Oct 28, 2015

Maybe you should say what you have tried then people can suggest things you haven't?

Back flush the matrix? Check the fins aren't gummed up?

Thomo1927 · Oct 28, 2015

New thermostat,water pump.I'll flush the matrix out this weekend. Thank you

discool · Oct 28, 2015

Is the engine running any cooler than before, if so the thermostat could be stuck open, rare I know.
Are the pipes to the heater matrix hot as they should be, "very warm" how hot is that? I only know cold, warm or hot.
Then there's the blending dampers, is the heater output the same on both sides with the controls set equally?

discool · Oct 28, 2015

Thomo1927 said:
New thermostat,water pump.I'll flush the matrix out this weekend. Thank you

Will that be a back/reverse flush ?

Thomo1927 · Oct 28, 2015

discool said:
Is the engine running any cooler than before, if so the thermostat could be stuck open, rare I know.
Are the pipes to the heater matrix hot as they should be, "very warm" how hot is that? I only know cold, warm or hot.
Then there's the blending dampers, is the heater output the same on both sides with the controls set equally?

What I have noticed is from start up when I go to work ,The engine temp gets up to just under halfway quicker than it used to. The pipes are hot

biolandy · Oct 28, 2015

Are you sure the heater is not air locked?Otherwise it is blocked.

discool · Oct 28, 2015

Thomo1927 said:
What I have noticed is from start up when I go to work ,The engine temp gets up to just under halfway quicker than it used to. The pipes are hot

Well if the "pipes" are hot that's a good sign, it means that hot water is flowing through the heater matrix.

Thomo1927 · Oct 30, 2015

Tried bleeding the system for 10 mins and can't see any bubbles coming out. The 2 hoses on the rear of the head that go into the matrix ,One is hot and the other is noticeably cooler ? Is that right

discool · Oct 30, 2015

Obviously there will be a temperature difference between the two pipes, but noticeably ? Both should be hot, did u have the fan blower on full.
The flow-in pipe will be the very hot one.

Thomo1927 · Oct 30, 2015

discool said:
Obviously there will be a temperature difference between the two pipes, but noticeably ? Both should be hot, did u have the fan blower on full.
The flow-in pipe will be the very hot one.

Yes one was noticeably hotter than the other,Heaters were on full.

discool · Oct 30, 2015

Turn the blower off how's it then? if the same it seems if the water isn't flowing through the matrix, but there's only one way to find, disconnect the return pipe and check the flow.

Thomo1927 · Oct 31, 2015

discool said:
Turn the blower off how's it then? if the same it seems if the water isn't flowing through the matrix, but there's only one way to find, disconnect the return pipe and check the flow.

Thanks discool,I'll check it out today.

Thomo1927 · Nov 1, 2015

Update ,Just for the sake of it I put another thermostat in and flushed out the matrix. Lots of black stuff come out ? Took her for a run and bled the system,Loads of air come out .Heaters now very warm .Now I have a happy pregnant Mrs. Cheers everyone

discool · Nov 1, 2015

Oooo black stuff, great then u sorted it and a very important person VIP is pleased

biolandy · Nov 2, 2015

Might be worth flushing again in another week or so,might be more black crap to come out yet

Thomo1927 · Nov 2, 2015

biolandy said:
Might be worth flushing again in another week or so,might be more black crap to come out yet

Thanks mate

Heaters playing up

Thomo1927

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blue beasty

Leaks an prone to bits dropping off

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blue beasty

Leaks an prone to bits dropping off

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