C4 2010 heater issue Help needed

[admiral51]

Hi all, asking for help as usual

The car in question is my 2010 C4 new shape vin in my signature.
I have not driven it for best part of 6 weeks but it has been used daily by other members of my family so not been parked up.
I took it today and there is very little heat coming from the heater, luke warm at best on both sides. I have done a search on here and found a lot of stuff about the C4 Picasso heater matrix but not sure where to start looking for a solution.
The car doesn't have a temp gauge so my original thought this morning was thermostat being open but even after a 35 mile run it was only warm air coming through the vents.
On the way home i tried different temp settings including A/C set to low. A/C works fine and all vents/direction settings work but it took a good few minutes to get the luke warm air coming out of the vents when going from low to hi.
High fan speed setting makes the luke warm air colder as if it is outside air not being passed through the heater matrix. The air on the passenger side does seem to be a little warmer than the drivers side but not hot even when set on high.
Any advice greatly accepted.

Thanks
Colin

[GiveMeABreak]

I think you probably need a coolant check and service. They should be able to check the system and flush through in case it's blocked somewhere.

[RichardW]

Check the coolant level first, heater is usually first to go if not enough coolant.

[admiral51]

Thanks Marc and Richard.
I have checked the coolant level and that is right on the max.
Just out of idle curiosity whilst out this morning i had the setting to high both sides and direction set for the vents on the dash. I had luke warm air coming out as before but i turned the re circulation button on and within seconds i had proper hot air coming out. Even with fan set to max the air temp was still hot.
As soon as i turned re circulation off i had luke warm air coming out. re circulation back on and hot air coming out.
Any ideas?
Marc what would be a reasonable cost for a coolant flush just so i have a figure to work on.

Thanks

Colin

[admiral51]

I have this car serviced every year, oil filters etc at MOT including pollen filter but can someone show me where the pollen filter is located just so i can check it out.
Thanks
Colin

[PaulC5]

Open the bonnet and looking from the front of the car, at the back left hand side of the bulk head there is a flap that pulls off and the pollen filter is there.

[admiral51]

Thanks Paul
i struggle with the mechanics of the climate control and how the magic works, old school with the xantia the filter was after the blower. in my head the heater matrix is doing its job but if the filter is pre blower and recirculataion flap would a blocked filter cause my issues ?
If any one could post a picture/diagram of the pollen filter location i would be most grateful cos i can break anything.

Thanks

Colin

[PaulC5]

If the filter is blocked then the air flow from the outside would be reduced so with the blower on full the air flow coming out of the vents would not be much. I suspect you do not have a heater matrix or coolant flow problem if you can get hot air on recirc. If you are getting a good air flow then it might be the hot air flap is not in the hot position for some reason but just when not on recirc.

[admiral51]

Paul i will check the difference in air flow tomorrow, i hadn't thought about that bit to be honest.
It will only be a paper test on the vents to see if there is a difference.
Thanks for your replies it does help

Colin

[PaulC5]

This video shows how to remove the cabin filter

[admiral51]

Thanks for link Paul. Took the old filter out, to be fair it was pretty clean and very little difference between air flow with it in or out and between recirculation on or off.
It definitely is not getting properly hot whatever i try at the moment. It does seem that it is getting some heat through the matrix but not enough so when you turn the blower speed up the air is luke warm, only low speed setting the air is much warmer.
Think it is going to be a coolant flush or a coolant flush and matrix replacement but can live with it for a few more weeks unless we get a cold snap.

Thanks for all the advice.

Colin

[Skater5]

Hi Colin,

I seem to have the exact same problem with my C4. Have you managed to find a successful remedy?

Kind regards, Stephen

[admiral51]

Hi Stephen,
Not yet no. It is going in tomorrow for a coolant flush. However i am having doubts that they understand exactly what i require.
They are talking about taking the thermostat out which as far as i can tell comes with the thermostat housing.
My issue is not with over heating or thermostat not opening or being open all the time. In my head the cleaning product added will work without the thermostat removed, in fact it should work better and target the heater matrix with the thermostat closed.
It will be fun when i get there tomorrow at 08:30 as i want a written quote with the name of the product they are going to use before i hand over the keys .
I will reply here tomorrow.
Colin

[Skater5]

Hi Colin, thanks for replying. I'll keep my fingers crossed for you. Look forward to hearing how you get on.

Best, Stephen

[admiral51]

Hi All.
Car has been in for 36 hours and the prognosis is that it is the heater matrix that needs replacing.
I was leaning towards that outcome at the start but hoping a flush would solve the problem.
Good news is i have total cost for a new matrix, fitting, coolant change and bleeding, road test and 1 years warranty for £380 inc VAT.
Yes i can do it myself but with having to keep an eye on the Anti Freeze with a dog and other pets around it is going to cost me £240 above what i can get the matrix for alone.
They cannot do anything with it until Friday next week but i can manage that with vehicles available.
And yes the £380 includes the work done to diagnose the issue, not been charged separately for that but guess it has been added in to the total which i am ok with.
Fingers crossed this time next week i have a positive update and a C4 with a toasty heater.

Colin