Ventilation distribution problem

Steady-Eddie · 20th October 2008, 20:58

Does anybody know which of the heater blend motors controls the hot/cold air flow between the screen and foot well?

Everything is fine for the first 30-40 minutes of a journey and then the heater decides that what we really need is cold air up the screen and very hot air to cook our feet.

Had it in the dealers a few weeks ago to have the new key coded and asked them to check out the heater controls while it was hooked up to the T4. Guess what? That's right. Nothing's wrong!! Just like a toothache that disappears as soon as you get to the dentist's door.

Only thing I can think of is it's a faulty blend motor unless any of you has any ideas

Simon · 21st October 2008, 21:47

The heater system usually does deliver warm air to the foot vents and cooler air to the face vents. If however the air is excessively hot then there may be a problem. What settings do you have the ATC panel on? If you haven't already done so use full auto control with the temperature around 22*C. This should be ideal in this sort of weather at the moment. I use this setting and find it very comfortable only notching it a degree or two cooler in much hotter summer weather.

Steady-Eddie · 21st October 2008, 22:02

I normally have the temp. set to 21 with the distribution set to screen and feet. Even on auto the problem surfaces after about 30 minutes driving with cold air from the face vents and hot air to the footwell. The only way to get hot air on the screen is to select screen only and turn the temp right up.

Not a problem in the summer but now it's getting colder I could do with sorting it.

raykay · 22nd October 2008, 12:46

The heater by-pass thumbwheel under the clock may be open, it allows cooler air through the face level vents if it is open, heated air if it is closed. Turn it towards the white spot to close it.

Steady-Eddie · 23rd October 2008, 07:21

That only controls the face vents though. My problem is with cold air on the screen as well as the vents

Steady-Eddie · 24th November 2008, 21:50

Continuing on from my original post about my heater problem:

The left hand heater distribution motor has started "cycling". Only found out about it when it started clicking. It stops clicking when the system decides after about 30-40 minutes that what I really need is a cold screen and sweaty feet (even when the outside temp is freezing). Tried disconnecting the battery for a couple of hours to reset things but to no avail.

Have asked Les about a motor and I've to ring back with the code number off the side. Would it be worthwhile changing the BCU (he's got the right one on ebay) while I'm at it, just to cover all angles? If I change the BCU for a 2nd hand one, would I have to get it programmed by the local X-Part dealer (who by the way couldn't find any fault when they had a look)?

20th October 2008, 20:58	#1
Steady-Eddie Avid contributor 2004 75 CDTi, Conn SE Join Date: Dec 2006 Location: Newcastle under Lyme Posts: 162 Thanks: 32 Thanked 5 Times in 5 Posts	Ventilation distribution problem Does anybody know which of the heater blend motors controls the hot/cold air flow between the screen and foot well? Everything is fine for the first 30-40 minutes of a journey and then the heater decides that what we really need is cold air up the screen and very hot air to cook our feet. Had it in the dealers a few weeks ago to have the new key coded and asked them to check out the heater controls while it was hooked up to the T4. Guess what? That's right. Nothing's wrong!! Just like a toothache that disappears as soon as you get to the dentist's door. Only thing I can think of is it's a faulty blend motor unless any of you has any ideas __________________ Eddie

21st October 2008, 22:02	#3
Steady-Eddie Avid contributor 2004 75 CDTi, Conn SE Join Date: Dec 2006 Location: Newcastle under Lyme Posts: 162 Thanks: 32 Thanked 5 Times in 5 Posts	I normally have the temp. set to 21 with the distribution set to screen and feet. Even on auto the problem surfaces after about 30 minutes driving with cold air from the face vents and hot air to the footwell. The only way to get hot air on the screen is to select screen only and turn the temp right up. Not a problem in the summer but now it's getting colder I could do with sorting it. __________________ Eddie

23rd October 2008, 07:21	#5
Steady-Eddie Avid contributor 2004 75 CDTi, Conn SE Join Date: Dec 2006 Location: Newcastle under Lyme Posts: 162 Thanks: 32 Thanked 5 Times in 5 Posts	That only controls the face vents though. My problem is with cold air on the screen as well as the vents __________________ Eddie

24th November 2008, 21:50	#6
Steady-Eddie Avid contributor 2004 75 CDTi, Conn SE Join Date: Dec 2006 Location: Newcastle under Lyme Posts: 162 Thanks: 32 Thanked 5 Times in 5 Posts	Continued Continuing on from my original post about my heater problem: The left hand heater distribution motor has started "cycling". Only found out about it when it started clicking. It stops clicking when the system decides after about 30-40 minutes that what I really need is a cold screen and sweaty feet (even when the outside temp is freezing). Tried disconnecting the battery for a couple of hours to reset things but to no avail. Have asked Les about a motor and I've to ring back with the code number off the side. Would it be worthwhile changing the BCU (he's got the right one on ebay) while I'm at it, just to cover all angles? If I change the BCU for a 2nd hand one, would I have to get it programmed by the local X-Part dealer (who by the way couldn't find any fault when they had a look)? __________________ Eddie

21st October 2008, 21:47	#2
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	The heater system usually does deliver warm air to the foot vents and cooler air to the face vents. If however the air is excessively hot then there may be a problem. What settings do you have the ATC panel on? If you haven't already done so use full auto control with the temperature around 22*C. This should be ideal in this sort of weather at the moment. I use this setting and find it very comfortable only notching it a degree or two cooler in much hotter summer weather.

22nd October 2008, 12:46	#4
raykay I really should get out more....... Now Other Manufacturer Join Date: Nov 2006 Location: Co. Kerry Posts: 2,786 Thanks: 16 Thanked 310 Times in 283 Posts	The heater by-pass thumbwheel under the clock may be open, it allows cooler air through the face level vents if it is open, heated air if it is closed. Turn it towards the white spot to close it.