What's new
Peugeot RCZ Forum

Register a free account today to become a member. It's free! Once signed in, you'll be able to participate on this site by adding your own topics and posts, connect with other members through your own private inbox and take part in competitions!

Heater not working well

Geoff Anson

New Member
Joined
Aug 16, 2020
Messages
11
Reaction score
3
Points
3
Location
Sysney
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

Well-Known Member
Joined
Jan 16, 2020
Messages
2,561
Reaction score
801
Points
113
Location
Cheshire
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

Member
Joined
Jun 3, 2020
Messages
65
Reaction score
33
Points
18
Location
PE10
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

New Member
Joined
Aug 16, 2020
Messages
11
Reaction score
3
Points
3
Location
Sysney
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

Active Member
Joined
Feb 23, 2020
Messages
218
Reaction score
68
Points
28
Location
London
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

Well-Known Member
Joined
Jan 16, 2020
Messages
2,561
Reaction score
801
Points
113
Location
Cheshire
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

Active Member
Joined
Feb 23, 2020
Messages
218
Reaction score
68
Points
28
Location
London
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

Well-Known Member
Joined
Jan 16, 2020
Messages
2,561
Reaction score
801
Points
113
Location
Cheshire
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

Member
Joined
Jun 3, 2020
Messages
65
Reaction score
33
Points
18
Location
PE10
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

Member
Joined
Jun 3, 2020
Messages
65
Reaction score
33
Points
18
Location
PE10
Also looking for a ' small' RCZ steering wheel if anyone has one.
 

Goatz

Active Member
Joined
Feb 23, 2020
Messages
218
Reaction score
68
Points
28
Location
London
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

Member
Joined
Jun 3, 2020
Messages
65
Reaction score
33
Points
18
Location
PE10
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

Active Member
Joined
Feb 23, 2020
Messages
218
Reaction score
68
Points
28
Location
London
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

Moderator
Staff member
Joined
May 7, 2014
Messages
3,204
Reaction score
720
Points
113
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

Well-Known Member
Joined
Jan 16, 2020
Messages
2,561
Reaction score
801
Points
113
Location
Cheshire
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

New Member
Joined
Mar 8, 2020
Messages
25
Reaction score
1
Points
3
Location
Mongolia
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

New Member
Joined
Sep 3, 2023
Messages
8
Reaction score
0
Points
1
Location
Kent
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
 
Top