Citroen C4 not blowing hot air

[knvr]

Hello forum members,

I am new to this board and apologies if my question has been fully / partially answered on a different topic:

I have a Citroen C4 1.6 VTR+ 2013 reg (petrol) and since a week it started to stop blowing hot air even on full heat. It takes about 45 minute drive for the air only to become slightly warm and it does not turn hot no matter for however long you drive after that. Took it to my local garage who thought it would be a thermostat problem and after a lot of struggle (labour and finding the correct replacement part) they finally replaced it (burning a whole of £200 in my pocket) and the problem is still not resolved. They now feel that it might be the radiator (not the big one, but the small heating radiator) could be blocked, and quote around another £200 for this part itself! Hence this request to find out if there are any other places / things to check if a failed fuse or something similar might be causing this issue? I am not very technical when it comes to cars, hence my finding in laymen terms as below (please advice if I need to check anything further to give more info):

1. Car AC is working fine blowing out chilled air either slow or fast depending on the fan speed, my car has three manual controls (rotating knobs) for hot / cold selection, fan speed and direction of air flow. AC switch is electronic (located on the second knob) where you just press A/C button.
2. The fan speed increases and decreases as normal, as per the speed selected.
3. The fan speed reduces slightly when turning from full cold to full heat. For Ex: You can hear/feel a slight reduction of speed when you change the temperature knob from full cold to full heat with the fan speed on let's say 4 or 5.
4. The air (even on full heat) only turns slightly warm after about 40 mins or so of driving and does not become hot after that.
5. The garage has replaced the thermostat and flushed the coolant and refilled it up, with no success
6. They also checked the hot / cold flaps under the panels near the foot of the driver side and said the cables and flaps are absolutely fine.
7. They then checked the small heater radiator under the panels on the passengers foot side and say that some inlet pipe is hot, but the outlet is cold, which makes them think it may be the heating radiator and gave me a quote of another £200.

Cant afford another £200 to find out something very minor was causing the issue, hence would appreciate the expertise and advice form the forum if anyone has come across this kind of issue or know a possible solution to fix it. Please let me know if you need any pictures or more info on the vehicle and I can PM that you.

Thanks,

NK.

[GiveMeABreak]

See my post here:

It's possible the heater matrix is blocked up, so the coolant isn't passing through it and therefore there is no hot coolant in the matrix. Therefore when the blower operates, there is no heat in in the matrix to create the hot air. The blower will be blowing unheated air. Ultimately you need to be careful as if the matrix gets blocked up it can cause cooling problems with the engine if the flow is blocked.

It will need removing and flushing through - but always ensure the o rings are replaced.

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[Zakk]

Hi have you solved heat problem as my ds4 has the exact same problems thanks

[nicknut90]

Hi. Really sorry to jump on an old thread but any updates from either of you on this? Similar situation - fans working, but no heat (Luke warm at best after 40 minutes of driving). Engine temps are stable. Diagnosed by garage as faulty thermostat, and replaced at similar cost to OP but no not made any difference. Second diagnosis back in suggesting head gasket but would need further testing to be sure. Not ruling this out (rough ideal on occasion but no signs of coolant in oil, or oil in coolant) but looking for other possibilities including blocked radiator and /or heater matrix. 1.6DSI 2011 with 180,000 miles. Any knowledge or information would be greatly appreciated. Nick

[Joaobasso]

I have a similar problem on my C4. My car has independent temperatures for left and right side. Only on the left, it gave always cold air. Mechanic says there's a "small plastic ball" in the system which has deteriorated, and isn't sold separately as spare part. Would be needed to change an entire big part of the system at high cost. He was able to keep it fixed at warm air, and when summer comes I can return there and fix it to cold again. But to have temperature control again I would need to find a replacement for that "small plastic ball".

[TeessideTyreMan]

I had this exact issue! Start of with the basic top up the collant mine looked OK however it was just above minimum I topped it full. Took car for a drive to let it make it's way round. Today I felt big difference in the heaters much warmer. Check the coolant again if dropped slightly top up go for a run and hopefully that should sort it.