Blowing Luke warm air

[Stook]

My 64 plate mk3 Octavia has developed a fault where Luke warm air is blown from the vents. The air is always the same temperature regardless of what I set it at. It's probably coming out at what I would expect if it was set at about 18 or 19c which it typically is. 

 

A local independent has checked the heater matrix and that is fine. He says that the an error code is showing for the climate control but his equipment is unable to provide any more details so has suggested I contact Skoda.

 

The car is going in on Wednesday. I told them over the phone what had been done so far but the lady told me that they would have to do their own diagnostic check which will be minimum of £96.

 

I have run the vent / flap check which does perform some tests. What I have noticed though after doing this is that when I turn the knob to increase /decrease the fan speed the 3rd led does not light up. I guess this is indicating something.

 

Anyone have any thoughts on this? 

[brettikivi]

a VCDS scan should tell you which of the flaps is not working correctly - temp, direction or what. It's also possible that there's an issue with the blower itself, but that should be testable by setting up / full power and running through each setting, up - face - floor - cold - hot

 

- Bret

[Stook]

11 minutes ago, brettikivi said:

a VCDS scan should tell you which of the flaps is not working correctly - temp, direction or what. It's also possible that there's an issue with the blower itself, but that should be testable by setting up / full power and running through each setting, up - face - floor - cold - hot

 

- Bret

 

Thanks for your response.

 

If a flap isn't working could this be due to either a mechanical fault with a flap or software? If there is something physically wrong with a flap I assume this is a dashboard off job to repair and therefore will be expensive?

 

There doesn't seem to be an issue with the amount of air coming out at each setting. 

 

I mentioned the 3rd LED on the dial. It seems to be the 2nd. I'm not sure if it was actually ever 3rd - I may have got mixed up. Anyway, what I've also noticed when the dial is set in the 2nd position is that the Auto  and Air Con lights come on and then when I turn the dial off the 2nd position they go off.

[brettikivi]

mechanical. Not necessarily dashboard off. I suspect the flaps are similar to the older ones; there's a potentiometer in there which tells the system the position of the flap to a reasonable level of accuracy. A Basic Setting may reset things enough for it to work correctly again. 

 

The two LEDs when on Auto - that's just because the level of fan corresponds to the level the system thinks it needs for the temperature you have set. 

 

To test: have the car warm, engine running. Turn temp to HI. Put all air to the windscreen; turn the fan up to four LEDs. Is the air at the screen hot? 

Now turn it to the face; does it still blow a similar amount of air? Is it still the same temperature? What if you put the air to the floor and the screen? Or face and floor?

Is it also only on one side or are both sides affected? Is the noise the system makes consistent?

Repeat with temp on 17 or so.... and note down where it's different.  This will help your mechanic to work out where the failure might be. 

 

 - Bret

[Stook]

2 minutes ago, brettikivi said:

mechanical. Not necessarily dashboard off. I suspect the flaps are similar to the older ones; there's a potentiometer in there which tells the system the position of the flap to a reasonable level of accuracy. A Basic Setting may reset things enough for it to work correctly again. 

 

The two LEDs when on Auto - that's just because the level of fan corresponds to the level the system thinks it needs for the temperature you have set. 

 

To test: have the car warm, engine running. Turn temp to HI. Put all air to the windscreen; turn the fan up to four LEDs. Is the air at the screen hot? 

Now turn it to the face; does it still blow a similar amount of air? Is it still the same temperature? What if you put the air to the floor and the screen? Or face and floor?

Is it also only on one side or are both sides affected? Is the noise the system makes consistent?

Repeat with temp on 17 or so.... and note down where it's different.  This will help your mechanic to work out where the failure might be. 

 

 - Bret

 

I can't test this until this evening but from the playing around I have done already:

With warm engine (90c) and temp at HI on fan blowing on high the air is cool. It's not as cold as the air outside so there is some warming of air.

 

If I move to face or feet the amount of air blown is still high but the temperature remains the same.

 

I can get a small amount of heat out of the left hand face vent only although perhaps a bit of heat out of the middle vents at one point.

 

I didn't notice anything usual about the noise when changing speeds, direction and temperatures etc.

 

I did notice a weird clunking noise going on when I turned the engine off a couple of days ago but that hasn't repeated since.

 

[PetrolDave]

On a previous VAG car I had a problem with the temperature control flap to the front passenger keep throwing an error.

 

On investigation the motor and potentiometer were fine but there were moulding flashes on the two levers that would occasionally jam, so I took the mechanism apart (it just unclipped) which only needed the glovebox removing and filed off the flashes. Problem fixed for zero cost, so don't just suspect the motor, check the mechanism for free movement too.

Edited 5 November, 2018 by PetrolDave

[Saints92]

I seem to have an issue where the blower does blow to the football at the drivers side, assume this could also be a flap issue?

[brettikivi]

yes. A scan and basic setting should show this up....

 

 - Bret

[Saints92]

4 hours ago, Saints92 said:

I seem to have an issue where the blower does blow to the football at the drivers side, assume this could also be a flap issue?

 

Meant to say doesn't blow to the footwell. 

 

I'll blame autocorrect for that one.

[Wildman]

Saints92 - did you ever solve your problem with the heating?  I seem to have the same problem with my Octavia Scout.  I used a trailer last week, plugged in the electrics, (I think but can't be absolutely sure) the heating stopped working properly after this.  Could a fuze be a problem?