No hot air from the heater

[nigelm]

I have a problem that’s developed overnight. The heater kicks out cold air only. All fan speeds work normally. My thermostat works ok I think- at least the temp gauge shows a normal rise in temp.
Is there anything I can check easily before going to seek help?
How do I check the rotary knob is working? Is there a diverter flap I need to check out? How? Where?
What else guys? Also any pointers to a simpleton’s guide to the parts and functioning of the heating system?
Looking at past threads Greg had a similar problem Oct 03. No info on how it ended though?
It’s one of those can’t wait problems as this morning’s heavy frost demonstrated. My joy on eventually getting past the frozen locks and door seals with a bucket of water changed to frustration and obscenities. Even more annoying as the water I’d sloshed on promptly added half an inch of ice to the windscreen. A can of de-icer will be a must for tomorrow morning. Does de-icer really damage plastic / rubber trim? It’s a rumour I’ve heard and I generally don’t use it.

Thanks guys

Nigel m ABY coupe

[Stick Insect]

I think you will find that you have a blockage or an air lock in your heater matrix. On the earlier cars my 1990 Cq20v as well there is a bleed valve on the rubber pipe going to the heater. this is just in front of the passenger on the bulkhead and is a small circular plastic knob. be careful turning it as they can be fragile and jammed after many years of just sitting there. run the enigine and bleed any air out.

I don't like using de-icer as they seem to shorten the lives of wiper blades.

If you know it will be frosty, lift the wiper arms off the screen the night before ( not is you park the car on the street tho'!) this will help when clearing the screen and help wiper blade life.

I have a heated screen and have not used de-icer for 7 years

Another tip if the car is on a pprivate drive etc. put a fan heater in the car and run that for 15 minutes before going out to the car ( put it in the night before. This clears the screen, warms the car and stops the doors jamming. you can turn it on from inside the house whilst wearing your pyjamas!.

HTH

David

[Fat Audi 80]

Another tip if the car is on a pprivate drive etc. put a fan heater in the car and run that for 15 minutes before going out to the car ( put it in the night before. This clears the screen, warms the car and stops the doors jamming. you can turn it on from inside the house whilst wearing your pyjamas!.

HTH

David

LMAO! Pyjamas!

[nigelm]

No hot air

I think you will find that you have a blockage or an air lock in your heater matrix. On the earlier cars my 1990 Cq20v as well there is a bleed valve on the rubber pipe going to the heater. this is just in front of the passenger on the bulkhead and is a small circular plastic knob. be careful turning it as they can be fragile and jammed after many years of just sitting there. run the enigine and bleed any air out.

I don't like using de-icer as they seem to shorten the lives of wiper blades.

If you know it will be frosty, lift the wiper arms off the screen the night before ( not is you park the car on the street tho'!) this will help when clearing the screen and help wiper blade life.

I have a heated screen and have not used de-icer for 7 years

Another tip if the car is on a pprivate drive etc. put a fan heater in the car and run that for 15 minutes before going out to the car ( put it in the night before. This clears the screen, warms the car and stops the doors jamming. you can turn it on from inside the house whilst wearing your pyjamas!.

HTH

David

Thanks very much. I've now found that above 2000 revs hot air is produced. I presume this still fits with the blockage or air lock theory?

Nigel M

[Greg_S]

Nigel, On mine it turned out to be the flap had been forced around too far once so on full heat the flap was only 1/2 way across. hopefully bleeding your system should sort it :0

Greg

[Lee]

My car only blows out hot air when the engine is FULLY up to temperature. Today I went for a spin (thermostat must be on the way out) but it took 6 miles to warm up. As soon as the engine got to temp the air from the blower instantly went from cold to hot. I was pulled up at the time with the engine running and I heard a little click as the air temperature changed.

Does the I5 look after itself first? ie does it wait until it is fully (I mean FULLY) up to temp before diverting hot water to the passenger cabin and heater system? If yes then this could be at fault. Your car is going to take a lot longer to warm up in very cold weather and if your thermostat is dodgy then it could take a bit longer. My thermostat goes once a year and I will need to change it soon.

My car had a fuelling problem a while ago which meant I was running very rich. THe heating never worked because the engine was running too cool.

Anyone else noticed this??? Could this be Nigel's issue???

[porkkis]

Lee you're running low on coolant or there is air in the heater matrix. Try to fill the coolant tank and try again. You can overfill the tank as the extra just comes out though the cap. A bit messy, but no harm.

You might also want to rev the engine over 3k when that happens, I mean no warm air before thermostat opens. It helps.

[Lee]

Coolant level is fine. I don't think there is an airlock. The thing that really confused me was the little click (like a relay working) just as the air went from cold to hot. I was just wondering whether there is a feature in the S2 to make sure the engine is up to temp before the heater gets any hot water. It was an instant change in temperature. The engine was ran at over 3000rpm when warming up but my thermostat is definately shot...again. Very cold here today too, well not by Finland standards I guess.

[porkkis]

Only -6C now, gladly there is snow

Dunno if RHD airconned have different setup, but in all LHD cars coolant runs in the matrix all the time. Climate equipped cars have an extra temp sensor in the input hose.

[Lee]

Hovering around 0C here. Great for performance but summer tyres are poor in this weather. I, like most others int he UK do not run winter tyres.

Can't wait for some snow. Great fun with summer tyres and 4WD. LOL.

I did have air con but I removed it. Maybe I have upset something by removing all of that heavy rubbish. from the front of the car. If anyone can support this let me know and pleaase tell me if I need to remove any fuses or bypass relays to help me have a warm car in the morning!!

[audiman]

The UK S2 had manual AC. Im not sure how the heater box works, lots of modern cars have hot matrixs all the time and just use a flap to shut off the heat

[Lee]

I will check for airlocks today. Just a bleed by the bulkhead and another atop the rad??

[audiman]

yep thats it Lee. Be warned that the one in the hose is probably seized and they can break off!!

[s2avant]

Watch out for the bulkhead bleed screw. They appear to be made of playdoh and you can't buy them separately.

Mine is snapped of but holds water so isn't a major problem. You can still get it to bleed the old fashioned way by having the blowers and heater on full blast.

I've been sorting out one of my customers with a load of bits for his V6 coupe and he snapped the screw on his. He's a landrover specialist and has found that the bleed screw from a discovery fits perfectly.

Part number PYP 10008 if anyone needs one.

Ben

[Stick Insect]

Watch out for the bulkhead bleed screw. They appear to be made of playdoh and you can't buy them separately.

Mine is snapped of but holds water so isn't a major problem. You can still get it to bleed the old fashioned way by having the blowers and heater on full blast.

I've been sorting out one of my customers with a load of bits for his V6 coupe and he snapped the screw on his. He's a landrover specialist and has found that the bleed screw from a discovery fits perfectly.

Part number PYP 10008 if anyone needs one.

Ben

The same bleed screw is on lots of Citroens/peugeots as well if you are in a scrapyard.

David