Heater stopped working - any ideas?

[Stripey]

I have the standard air con and a few days ago during a fairly long journey the blowers went cool and turning the knob to full heat made no difference. A/c on or off, fans on low or high, directed at windscreen or feet makes no difference.

There's no fault light on the screen. I've checked the fuses and they all seem OK. What else it could be. Any ideas?

 

[Mr Juicebox]

Grab a scan tool and scan the body module for codes. Second step would be to verify that the blend door is opening for heat.

To me, it sounds like the blend door is not opening.

 

[AntGTD]

Stripey - where are you in the UK?

 

[Stripey]

Thanks juicebox, I'll have to look into the blend door issue.

I'm in Milton Keynes Ant.

Trying to avoid a visit to the dealer so if there's anything obvious I can try first I'll try it!

 

[AntGTD]

Thanks juicebox, I'll have to look into the blend door issue.

I'm in Milton Keynes Ant.

Trying to avoid a visit to the dealer so if there's anything obvious I can try first I'll try it!

If you can't track down another member with VCDS and find yourself in the Hampshire/Berkshire borders area drop me a PM

 

[Stripey]

If you can't track down another member with VCDS and find yourself in the Hampshire/Berkshire borders area drop me a PM

Cheers Ant

 

[Chris43]

Stripey - its a long shot but have you checked your coolant level? If its low the water may not be filling the heat exchanger matrix properly. Can you hear water gurgling around the system, another indication the coolant is low.

 

[patarch]

I had a very similar problem and the dealer just changed the vent actuator motor. (Or something like that) There was a weird sound coming from the driver side dash though.

I had a fault code when scanned.



Sent from my iPhone using Tapatalk

 

[Stripey]

Stripey - its a long shot but have you checked your coolant level? If its low the water may not be filling the heat exchanger matrix properly. Can you hear water gurgling around the system, another indication the coolant is low.

Thanks Chris. Interestingly, a week before this happened the low coolant warning came on and I checked and sure enough it was low so I topped it up. I topped it up in the dark with a torch so I may have filled up to the max line, although I was aiming for mid way between max and min. Do you think too much coolant might be the issue?

 

[Deviation01]

My heater didnt work from the factory. It was some kind of a sensor they had to replace and it was all good. Hopefully its an easy fix.

 

[Steve A]

Check the fluid level again, it's possible you have a leak somewhere.

 

[Chris43]

Thanks Chris. Interestingly, a week before this happened the low coolant warning came on and I checked and sure enough it was low so I topped it up. I topped it up in the dark with a torch so I may have filled up to the max line, although I was aiming for mid way between max and min. Do you think too much coolant might be the issue?

Possibly an airlock somewhere? I doubt too much coolant would stop the heater working, is there a pressure relief valve on the expansion tank?

Have you noticed any difference in the engine temp once its warmed up, running hot or running cold?

How many miles have you done? Its well documented on here that coolant levels dip during the first 1000 ish miles, my TDi drank loads at the start and hasn't used a drop since.

Can you park somewhere dry and watch for a wet patch forming, this would generally suggest a leak (but: dont confuse condensate dripping from the A/C as coolant loss)

 

[Stripey]

I checked fluid level again on a cold engine and it seemed really low again, although the warning light hadn't come on? I may top up again and see what happens. Will it cause any damage to have too much coolant in there?

 

[Chris43]

I checked fluid level again on a cold engine and it seemed really low again, although the warning light hadn't come on? I may top up again and see what happens. Will it cause any damage to have too much coolant in there?

Just top it back up to just under the max level on the expansion tank. You're not exceeding the capacity of the system. Have you checked the heater since you topped up?

TBH Until you've sorted this I'd be checking the coolant level daily, I hope not but worse case you could have a leak somewhere

 

[Stripey]

Possibly an airlock somewhere? I doubt too much coolant would stop the heater working, is there a pressure relief valve on the expansion tank? Don't think so

Have you noticed any difference in the engine temp once its warmed up, running hot or running cold? No it seems fine

How many miles have you done? 55000 Its well documented on here that coolant levels dip during the first 1000 ish miles, mine TDi drank loads at the start and hasn't used a drop since. This is the first low coolant warning I've had since new.

Can you park somewhere dry and watch for a wet patch forming, this would generally suggest a leak (but: dont confuse condensate dripping from the A/C as coolant loss) I can try!

.