Heater not working well

[Geoff Anson]

Hi there. I just got an RCZ. Cold day today so I pumped up the temperature and found that there was almost no warm air at all. Turned off the AC and had the setting on Hi and the air warmed up quite a bit but still not hot. All myother cars with climate control get hot when on Hi even with the ac still on. I checked online and there are posts about thermostats being faulty. Engine warms up quickly and stays stable so that does not look like the problem. Car has 50,000km so I don't suspect failed heating radiator or tubing fails, although not impossible. Fuses??

 

[Pedro]

If the heater blower is working flat out then it could be engine temp not getting warm enough the thermostat can affect a lot of things including the heater system but also coolant level issues can cause low heat problems you may even have an Air lock in the coolant system ?

 

[Bobby D]

Hi Geoff. I hope you have sorted your heater. If not here is what you need to do. Basically the heater matrix does not bleed itself when the coolant is changed for any reason. But it is easily fixed by using the air bleed that is fitted to the heater hose pipe as it comes through the firewall back into the engine bay. You have to remove both the air ducts that go to and from the engine air filter. You need to undo the top one at the fragile turbo end first and you will need someone to help you unclip the lower one as it has 2 release clips. The Top one is easily accessible but the bottom one is hidden and you need to do it by feel with a long flat blade screwdriver while someone else gently wiggles it off. Once clear the bleed nipple is immediately obvious on the top hot water pipe which goes to the heater matrix. Undo the cap til all the air escapes then repeat procedure in reverse. Don't forget to top up your coolant. Simples and toasty warm on a cold morning!!

 

[Geoff Anson]

Bobby D. All I can say is WOW! Many thanks. I have not fixed it yet as we are moving into spring and summer in Sydney so won't need it but I will now get it done at the next service. I just bought the car so I don't know if the coolant has been changed.

 

[Goatz]

Thanks for the instruction Bobby.
I unscrewed the cap but nothing came out. No air or coolant.
perhaps It is blocked and I need to stick a pin in it, or start the engine?

 

[Pedro]

Maybe you have a Air lock in the coolant system or the thermostat is sticking open its very very rare to get a blocked heater matrix but in the extreme cases take off the coolant expansion tank cap & leave the Engine running to get the water boiling hot if there is a blockage it will find its way back to the tank as its depressurising system failing that change the Thermostat

 

[Goatz]

Might not be as rare as you think Pedro. I see lots of reports of blocked heater matrix on 308's and peugeots/citroens in general on the internet. Luckily it is quite accessible compared to other cars, and an OEM unit can be picked up for under £50.

I managed to split the turbo hose while disconnecting it to access the bleed valve so will hold out before doing any more testing until the new new hose arrives.
I read last night about removing air from the coolant system by leaving the cap of and revving the engine with the heaters on full. I will give it a go! Am I ok to rev the engine without the air filter turbo hose or crankcase breather hose connected?

The coolant was changed recently when I had the oil filter housing gaskets replaced and I doubt they knew about the bleed valve for the heater matrix.

 

[Pedro]

You mentioning the coolant change is probably the reasons why the owners of the 308s etc have had trouble its mainly caused by crap going around in the coolant system from different mechanical issues regarding running with hoses off I would think the ECU would detect excess crankcase pressure from the sensor whilst running the Engine at Max Temp with the hose off & if your leaving the Turbo Air feed off from the filter what about the Maf sensor ? Plus you may get oil mist escaping from the pipe coupling making a mess so I personally would reconnect everything first before getting full coolant pressure otherwise you could end up wiping codes out
Better to be safe than sorry

 

[Bobby D]

Well as I say changed the Matrix which was good as new before discovering the bleed valve which solved the problem completely. So if anyone wants to buy a heater matrix for 40 GBP inc p and p let me know.

 

[Bobby D]

Also looking for a ' small' RCZ steering wheel if anyone has one.

 

[Goatz]

Well as I say changed the Matrix which was good as new before discovering the bleed valve which solved the problem completely. So if anyone wants to buy a heater matrix for 40 GBP inc p and p let me know.

So when you took the cap off did coolant come out rapidly or just dripping? and was the engine off and cold?

 

[Bobby D]

The engine was relatively warm as I had run it after the matrix change to get the thermostat to open (approx 90 degs). Opened the bleed cap, air came out then water, job done. Also had to put about a pint of coolant in to replace the air.

 

[Goatz]

Just an update, I solved the issue with the heater only blowing out tepid air by going for a long drive with the heater on full then parking and carefully unscrewing the coolant expansion tank. Becareful as this can scold. When released it will pop with pressure.
Do this process of driving and releasing a few times and the heat should come back. If not I guess you need a new heater matrix.

 

[neilgsxr69]

You can do the same by using the bleed screw if yours has one some were replaced with temp sensor with the nee style thermostat housings.

 

[Pedro]

Just an update, I solved the issue with the heater only blowing out tepid air by going for a long drive with the heater on full then parking and carefully unscrewing the coolant expansion tank. Becareful as this can scold. When released it will pop with pressure.
Do this process of driving and releasing a few times and the heat should come back. If not I guess you need a new heater matrix.

Yes Air locks can be a pig to get rid of I know the dealers will leave them all night & let Gravity do the rest according to my mate whose the service manager at teh local MD seems to work I know mine took around 2 days to settle itself after the tank was changed for the new one

 

[anandmongol]

Hi Geoff. I hope you have sorted your heater. If not here is what you need to do. Basically the heater matrix does not bleed itself when the coolant is changed for any reason. But it is easily fixed by using the air bleed that is fitted to the heater hose pipe as it comes through the firewall back into the engine bay. You have to remove both the air ducts that go to and from the engine air filter. You need to undo the top one at the fragile turbo end first and you will need someone to help you unclip the lower one as it has 2 release clips. The Top one is easily accessible but the bottom one is hidden and you need to do it by feel with a long flat blade screwdriver while someone else gently wiggles it off. Once clear the bleed nipple is immediately obvious on the top hot water pipe which goes to the heater matrix. Undo the cap til all the air escapes then repeat procedure in reverse. Don't forget to top up your coolant. Simples and toasty warm on a cold morning!!

Hi Bobby,

Can u plz show me with the photo - I have 2010 THP 156 - and my AC/Heater not working

1. Hi Geoff. I hope you have sorted your heater. If not here is what you need to do. Basically the heater matrix does not bleed itself when the coolant is changed for any reason. But it is easily fixed by using the air bleed that is fitted to the heater hose pipe as it comes through the firewall back into the engine bay. You have to remove both the air ducts that go to and from the engine air filter. You need to undo the top one at the fragile turbo end first and you will need someone to help you unclip the lower one as it has 2 release clips. The Top one is easily accessible but the bottom one is hidden and you need to do it by feel with a long flat blade screwdriver while someone else gently wiggles it off. Once clear the bleed nipple is immediately obvious on the top hot water pipe which goes to the heater matrix. Undo the cap til all the air escapes then repeat procedure in reverse. Don't forget to top up your coolant. Simples and toasty warm on a cold morning!!

 

[RichB]

Hi All!
I think it's my turn to have this same problem. I'm quite handy but a novice when it comes to heater systems. Any chance of some pics to tell me what I need to do?
Thanks, Richard

 

[Kirk]

I now seem to have an issue with the heating inside the car.

It's strange because the fans for the screen and cab are blowing cold, but the footwells are working as normal and blowing hot air. Just had the car serviced and they had a look at this blowing cold problem and say it is not an airlock in the coolant system.
It's really strange some of the system works and the rest doesn't Engine running and temperature is perfectly fine.

The mechanic is asking me to leave the car with him for a couple of days to work through the issue. It's starting to sound an expensive investigation. Does anyone have any piping diagrams of how the coolant and heater systems work ? This could help speed up any investigation.

Thanks
Kirk

 

[chrismac]

This seems to be doing the rounds like the Flu - I have the same problem.

It may have been an issue since the last service in September, its only since the weather turned cold that I have noticed. Going to have a look on the weekend, I will take a few photos .

 

[Mikefrank]

Mine gets warm but only after driving roughly 20mins ( My old Renault megane is warm after 5mins )…..
Going by past forums the Matrix is not the best on them maybe a new one will sort it and follow Pedros advice on bleeding the system the right way….