Disco1 overheating and no cabin heating

I have read the recent threads about Disco's overheating. Well, the first time mine did it I was towing a horse trailer with a large horse on board. The engine temp went up and steam came out from under the bonnet. I lifted the bonnet and saw water and coolant coming out of the reservoir. After topping up I managed to limp home. Whilst the engine was overheating I noticed there was no heat coming from the cabin heaters. I had the thermostat changed and it seemed to solve the problem but then I noticed the engine overheating and no cabin heater whilst driving without towing. Suddenly warm air started to flood the cabin and the heater switch dropped straight down to normal. Any ideas?

KarenB

Could have been an air lock clearing; did you have to top up the fluid after everything started working again?

Yup, sounds like an airlock working it's way through the system.

When the water is drained down from the system, some remains in small pockets in the engine and heater matrix.

When you refill the rad use the filling point on top of the rad top, do it slow, you'll hear the air glubbing around.

Fill the header tank to the level, run it up, watching for leaks, have the heating set to 'hot'.

Stop the engine, let it cool down, check the levels...it can take a couple of days to get all the airlocks out. Don't forget you still need coolant additive even if you think we'll get no more frost.