Volvo 940 only blowing cold air

[McGandalf]

Originally Posted by Laird Scooby

I'd replace the 'stat before going near the HCV if i were you. Before you start the drain, flush etc, ensure the heater is set to the hottest setting, it needs to be there so the matrix gets flushed too.

When you come to do it, invest in something like Comma X-stream Flush for the cooling system and add it as per the directions on it.

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Thanks for one of the clearest step-by-step guides to car maintenance I've seen on the Internet. Really first-rate.

Comma X-Stream Flush seems to be no longer available though - Evapo-Rust C715 Thermocure looks like a good alternative.

Have ordered a new thermostat - when it comes I'll run through the steps you suggested. I have a suspicion the coolant in the car might never have been changed in all its 29 years. It is the right colour though (blue/green, if you can still call it that).