Whats an aux heater and what does it do?

[bmwdumptruck]

Hi Guys

I've read through quite a few threads discussing faults relating to these heaters, but I think I'm a little confused as to what they're for.

Not had any smoke from my 02 tdi, but I hear it clicking from time to time, and whiring after runs.

Is it connected to the cabin heater system, as ours take forever to warm up in the winter. In fact this is the worst vehicle I've ever owned for winter demisting, and I've had some shockers over the years (HA Viva vans!!)

Or does my air con need refilling? Ive had the car four years, it was recharged a while before we bought it when it had a hose replaced. Should it need doing again?

[portovechios]

Aircon refill is for cooling not heat

[bmwdumptruck]

Aircon refill is for cooling not heat

But I thought the AC helped remove the moisture, therefore if it's not fully charged it won't help demist !

[portovechios]

AC provides cooling when the temp you punch is lower than the ambient temp. So if its 25 outside and you punch in 20 the ac will come in and reduce the outside air coming in to help bring inside temp down.

The time of the year the AC will not cut in because the ambient temp outside is lower than you require

Climatronic is the whole system that controls this.

If you're not getting heat it is nothing to do with the AC unless of course its stuck on.

Climatronic is a wonderful thing but your problem could be one of many things.when you adjust the temp from say 20 to 16 you should hear flaps and motors in the centre console moving and ticking etc

Does the engine temp get upto around 90 after 2/3 miles?

[portovechios]

AC does not demist, heat demists

[bmwdumptruck]

AC does not demist, heat demists

Well I hate to disagree with you, maybe you justnever tried it. But if we leave ours in ECON with 3 or 4 body's in the car the side windows mist up quite quickly. Stick it back on AUTO and the air con kicks in, the mpg drops by a couple of digits and the windows tend to clear again.

We also found it did it in our Avensis that we had before.

[portovechios]

Climate control in auto will boost heat and exchange air as it sees fit.All i'm saying is that AC is just the action of cooling and is a part of climatronic.

Regassing will not improve demisting but it will allow the climatronic to acheive lower than ambient temps

It might be that in newer cars they have demisters, i don't know!?

Hey..i'm no expert though

That is my understanding anyway

[100andthirty]

Misting is the action of moisture or humidity in the air condensing on cold surfaces, in this case glass. Air conditioning acts as a de-humidifier.
Climatronic set to auto has the air conditioning on all the time. The air is cooled by the evaporator, and is then heated to the required temperature in the heater matrix using the engine's cooling water. if the ambient temperature is below about 4.5C, the air conditioning is locked out by the car's system.

With the OP's symptoms, I'd want to check whether the auxiliary heater is actually getting hot and whether the engine thermostat is working

My auxiliary heater was very unreliable and I didn't want to spend approx £500 on a replacement. I too, therefore, suffer from slow warm up. What I do in cold weather is to turn off the heating altogether until the engine has got to temperature. If I do this, the engine warms up more quickly, and heating is more effective as a result. In the meantime I rely on the heated seats. I don't find it worth bothering to do this unless the temperature is below about 5C

[Wolverine77]

I have the same issues with the Aux heater and I recently turned the on board controls to ECON and fingers crossed no more smoke in the cabin as long as I keep the heater on full blast!!!!

It takes a long time for my Sharan to heat up is there anything I can do to sort this issue out?

[Holsokk]

Might be a little late, but i have heard of a guy that had this problem with sharan taking loads of time warming up(this was even with the auxiliary(booster) heater working). He problem solved this and changed the electric water pump(though he had installed a parking warmer) and it still would take alot of time to warm up the car.

He however got a tips and solved the problem.

The tip was to putting the car in a very steep slope with the front upward. Then race the engine at high speed for 5 minutes. (3500 rpm) This with the lid of the expansion tank off. Then the water pump circulating the water is in a suitably high speed and squeezes out air that may be in the system. This should be a self ventilating system on the car.

After a couple of minutes the heat came. He said he have never had it so hot in the heating system earlier. The next morning he tested the system and after 20 minutes it was tremendously hot in the car.

Worth a try if you have fixed the aux heater and it doesnt get warm enough. ;)