C4 Picasso 2015 (B78 plate) Heating problems

[kovacicn]

Hello,

Can someone help me to get wiring diagram for electric heater for Citroen C4 Picasso (b78) 2015

Thanks!

[Cretustf_21]

Hello everyone.
Can I have a little help with my heating system in my C4 GP B78.. I brought it like that and the last owner didn't mention that its not working properly.
So... its blowing warm(not hot ) in passenger side (UK ) and driver side its cold..when setted for hight temp, on low both side are blowing same cold temperature.
I have dismantled all underneath dashboard to have clear view at the entire heater block and to be able to see all flaps if they are moving, and yes all seems to turn as the construction plastic its pretty clear(denso).
The heater rad seems to be very hot on both pipes so I.m thinking its not blocked....
If someone able to sort it I.m happy to travel if needed..

[Chris570]

My one was blocked internally so only part of the rad would get hot. It seems to be a common theme..... You can try and flush and clean it, I managed to get mine 80% there with white vinegar and hot water and shaking. But I couldn't find a replacement core, otherwise I'd just have done that.

[glopes06]

Hello Tim, I have the exact same problem, could you please let me know if you work on a garage and if you could fix my car? I’m near Oxford but can travel. Much appreciated!

This is a known issue on all 2014 onwards Picasso or 308 vehicles and there is a tech bulletin on the issue as well. Denso heater system and the cores clog often. The replacement core is cheap and it can be easily changed without dash out. Just loosen the bolt securing the heater pipes on firewall to allow the pipes to move freely and disconnect from heater core end.

Slide out the old core and replace. Genuine kit includes new clamps and O rings.

U can also fix by using a flushing tool with compressed air and water but due to access it's just as easy to replace the core.



Tim

Citroen Peugeot specialist mechanic

[palmsings]

update...heater matrix was changed and everything is ok...cost - 150EUR

Hi,
I know this post was from 3+ years ago but we’ve got exactly the same problem right down the one vent that’s working. Car is RHD but still it’s the one vent on the left that is properly controlled.
You mention that the heater matrix was changed and it cost 150EUR. I’ve been advised that any exchange on the heater matrix is going to cost minimum of £700 due to the fact that the whole dashboard needs to be removed to access the heater matrix. Do you recall if the dash had to be removed in your repair or was it accessible some other way? Really hoping for some good news
TIA
Mike

[Chris570]

I can assure you the dash does not need to be removed. Easiest matrix I've ever got to.

[palmsings]

Thanks for the reply. Was it a grand Picasso? Ours is a 2017 and I know the original title of the post is about a 2015. Is there any more info you can share about how to access the heater matrix please?

[Jsntony]

Hi, sorry to bring up an old post but I'm having the same problem, so here's what I know

That hole is in the middle of 2 heater matrix one water and the other electric

So the air that comes out of that hole is pre water heater matrix

I have video of the flaps covering them moving and working

The air that comes out is ment to be either heated by the electric element or ment to be cold

There is a dedicated vent in front of this with the courtesy light attached which does blow hot air but is overpowered but this hole that blows cold air

Everything else windscreen, front vent and passenger blows hot air

I'm at a loss I haven't got a clue why this hole blows cold air but infront of it blows hot air it don't make sense

Thanks for any information and help