Thread: Heater in defender 90 not blowing hot air

I am not sure if they use a valve to open/close the hot water supply - check that first.

The other thing, even if the valve is open the thing could be airlocked - thus no heat - easy way to test if you can get your hand onto the heater matrix - ooops sorry you did say Defender ???

Have a ferret under the bonnet - chase the heater hoses - from the firewall back towards the engine - if there is a valve you will find it.

With the engine at normal running temp feel the heater hoses just where they enter/leave the firewall if they are both hot then there is a good chance water is getting through - if one is hot and the other just warm or cold - it's either an airlock or blocked with ****.

If its an airlock trace the longest hose from the firewall and disconnect - plugging the bit you have disconnected it from to stop loosing water - with the aid of an assistant or a bit of string - get that hose as high as you can.

Then disconnect the other hose - again plugging the opening where you disconnected it from - and again get it up as high as possible -

First flush it out with fresh water from a hose (not too high pressure) you may want to collect the first bits into a bucket to see how mucky it is/isn't.


then pour water/coolant mix into the highest hose until it starts to weep out of the lowest host - then as careful as you can without loosing too much coolant reconnect the lower hose to the original position.

Then add more water to the other hose till full, then carefully reconnect to the original position trying not to loose too much water.

Then bleed the full system - on the defender I think (could be wrong) that there is a bleed screw on the thermostat housing .

That is of course it is an air lock. The flush may have done the trick

As to where the controls should be to get heat - sorry haven't a clue - I drive a namby pamby Disco with a digital temp setting

Ok first things first
Check the fan is working now

And then open the bonnet look at the right hand side on top of the heater and fan unit. There are two leavers controled by a wire cable each. This is the other ends of the levers that you have in the cab. Check the cable has not come undone or stretched over time. . As this will not be activation the controls when you move them in the cab

Originally Posted by defender90

can anyone give me a few ideas of what may be the cause of no hot air when in correct position?
hasn't be used since last winter but did find the fuse had blown for the fan earlier in the week as ciggy lighter woundn`t work.

Do you mean not blowing air or the air isn't hot?

The fans rusted up.They fill up with water because the inlet faces up and because there is no drain they fill.Pull it all out,the motors can't be repaired and drill a hole in the bottom of the fan housing.The motors are dear but are used by most Euro makers,my VW Polo used the same motor on the engine fan. Pat

Originally Posted by PAT303

The fans rusted up.They fill up with water because the inlet faces up and because there is no drain they fill.Pull it all out,the motors can't be repaired and drill a hole in the bottom of the fan housing.The motors are dear but are used by most Euro makers,my VW Polo used the same motor on the engine fan. Pat

The rusting up of the fans more than likly the reason that your fuse blow in the first place

Originally Posted by Reads90

The rusting up of the fans more than likly the reason that your fuse blow in the first place

Several members seem to have had this problem.
There is a drain or rubber valve at the bottom of the plastic air inlet tube.
Mine filled with mud before I bought it and the fan motor was submerged and the fuse blew.
I undid the back of the motor house as much as I could and sprayed it liberally with WD40. Actually I flooded it with WD40. I did this a few times whileI I turned the motor by hand and with a rubber tube coupling on a cordless drill.
It gradually got better and then suddenly returned to normal. That was 18 months ago and it's still working perfectly.

Could be worth a try before you scrap the fan motor. It worked for me.