Noticed yesterday that the heater declines to blow hot air. There's hot water in the pipes leading to/from the heater, in the engine bay, and since the gas vapouriser is piped in series with the heater, i conclude that it's circulating correctly. The only obvious fault I can find in the heater controls is that the recirculating/fresh air thing is not doing the recirculating bit on account of a vacuum leak somewhere, but that shouldn't cause the observed symptoms.
The hot/cold control operates a flap at the bottom of the heater unit, I can see and feel the lever moving and hear the flap opening and shutting.
However... this flap appears to be fully shut about half-way through the lever travel, so I'm wondering, on this basis, whether there's another aspect to the hot/cold control which is elsewhere, and not happening.
I really don't want to have to remove the dash in order to get at it... so if anyone has any ideas or quick fixes...?
both HBoL and the "proper" manual are unimformative on the subject of how the heater controls operate, although they're prepared to tell me how to get 'em it all apart...