No heat from the heater. Ideas?

[MonkeyDust]

Hi all,

My mum's mk1 Eunos doesn't blow hot air anymore, when set to hot the best it can manage is vaguely warm. It gets colder when the knob is set to cold, so it's still doing something. She's hoping I can fix it next time I'm round, so any ideas are welcome.

[Eighteeteewhy]

Does it get cooler when she drives?

I'd start with a new thermostat.

[MonkeyDust]

No the engine temp is fine, the needle reaches the middle of the gauge and stays there.

[snotrag]

Check the hoses going in and out of of the bulkhead they might give away if there's flow to the matrix or not. If there is, then it likely down to the matrix itself, check the control cables etc are still attached. With glove box lid off you can get in easily.

[MX-5 Lazza]

It'll be the thermostat stuck open. The temp gauge doesn't mean much as they only have 4 settings, cold - warm - a bit too warm - too late boiling over look at all that steam!

[MonkeyDust]

Cheers guys, I'll have a look at it at the weekend. Will give me an excuse to take it out for a play too, I hope it's not raining