Heater Blowing Cold Air

[willni]

Hoping someone could shed some light on this issue.

My heater started to blow cold air lasts night when it’s set at 21 degrees, which to me is fairly warm. I removed the silica bag when I got the car at 4k miles and that was 6k miles ago. When i removed it it was all fully intact so I’m struggling to think what it could be.

[clubsport]

A nightmare, I dread this happening.
Have you run an OBD scan to see if anything shows up?

Only from prior forum postings, I have seen the first point to check is the heater matrix under the dash in front of the gear lever.
If you still have warranty running, it's not so much your problem?
Are the pipes or pipe warm going into the heater matrix?
Maybe flush out and refill the cooling system as a starting point.

If pipe is warm and heater matrix is still cold maybe it is clogged.....
Let's hope it was, but was that the original coolant tank you took the silica bag out of?

[madstaff]

Could also be an issue with item 15. Heater support pump or 17. Coolant shut off valve??

[Vwjap]

If you turn it up to max heat does it blow hot, I know mine when it gets up to temperature it blows cooler air do keep it at temp selected

[Finglonga]

First thing to try is a climate flap reset before doing any needless work.

Press and hold the AC button and the button for the air to come out the middle vents until they start flashing. It will make a few noises ans the flaps cycle and see if that helps.

[coolhandluke123]

I hadn't used my heating over the summer and when I first started to use it few months back had the same issue. I to had thoughts of blocked heater marrix but after a few weeks it seemed to sort itself and now all seems to be working.
It's still not a patch on my wife's 4 year old Polo's heater, virtually instant heat and would put you out of the car if turned full up.
Plus the Polo's bonnet release feels so solid and positive unlike the Golf's.
Wished they'd fitted all similar in the Golf.

[willni]

Cheers folks, I'll run a VCDs log and do a Climate Flap reset later on and report back. It seemed to be working better last night, I have a temperature laser gun somewhere so I'll add that into the mix to be more precise than "That feels colder/warmer"

[willni]

Update, VCDs Log shows no issues with the car except low voltage to the headlights for some reason, I've performed the Climate Flap Reset so will let you know later if it has worked when the car heats up.

[madstaff]

My Clubsport has expansion tank 5Q0 121 507 G and upon closer inspection has the dreaded tea-bag.

I mean, had a dreaded tea bag.

10 mins later and it's out, fortunately no signs of tears to the bag.

[Watts]

I find the heating on this car to be a bit erratic and it often feels too cool. Unless it's my age of course! My B6 Audi rarely needed to be set over 21c, then I got my PP which needed to be on 22c, this one often needs to be on 23 and is regularly on 24.

Hopefully the 'flap reset' will work, I had to change an actuator in my Audi as it had failed and was only allowing air out of one set of vents so could easily be the hot air input stuck closed.