Winter is coming - heater in-op!

[secondtimer]

So today I found the problem, and suddenly a couple of the problems with flushing all made sense.
The return channel back into the water pump (the one that sits under the inlet manifold coming from the heater) was solid...and I mean rock hard solid, with white crust. It was like limescale, but as a good dose of limescale removed didn't touch it I have no idea what it was. So for anyone else out there with a similar problem, if the return is so totally blocked the water an't flow back round to the pump, its going nowhere and certainly not round the heater matrix!

will do a final update once its all put back together with the new gaskets etc and can test what difference it makes.

[Toledo Man]

Have you tried a hosepipe or compressed air? Either of them should shift the crud. Failing that, you could try flushing the cooling system with some radiator flush.

[Jon Tilson]

That sounds like a combination of limescale build up and the sort of powdery corrosion you get from alloy and steel in proximity.

You could try and unscrew the pipe tail from the water pump cover. Otherwise the inlet manilfold and carbs have to come off to remove
or swap the pump cover. I suggest draining the block from the plug on the block behind the exhaust manifold as it doesnt all drain out
otherwise.

If you do have the cover off have a look at the recent mahesh (iirc) resto thread where this is described.

Jonners