I just noticed last night on my journey home that my heater is not blowing hot air anymore. The temperature gauge was sitting just above half way so the engine didn't seem to be overheating.
This morning I've checked my water/antfreeze levels and oil - both fine. I drove my children to school but ut the heater is still only blowing cold air. Engine seems fine?
Any advice or suggestions, anyone, please ?

Lisa

You probably have an air lock and the water is not flowing through the heater matrix (inside the cabin passenger side under the dashboard).

Somebody needs to bleed the system... with the engine hot and running first unscrew the white plastic bleed valve at the top corner of the radiator on the drivers side... water should trickle out eventually then close it.

Put the heater onto full and bleed the 2 black hoses that go from the back of the engine (passenger side) into the cabin bulkhead. First the lower down one (into the heater) - there is a circular black plastic disc that you unscrew.. do it up when hot water dribbles out.

Then do the 2nd hose (most important).. this is the return from the heater and the bleed valve is on the wavy side extension to the hose. This should release the air from the heater matrix, and may actually be the only thing you need to do.

If the water looks brownish then you need to get the whole cooling system flushed out and refilled with fresh water and antifreeze (probably a good idea anyway to protect the engine - should be done every few years).

Hope this fixes it....

Hi Bluejohn, thanx for your full and detailed response. I'll print that off and give it to my husband. Someone else told me it may be an airlock but they didn't tell me how to fix it. Hopefully your instruction will sort it.
Very grateful
Lisa