Morris Minor Owners Club

I've just driven 340 miles today in my Trav and the heater never got hot, I wouldn't even say it was warm.

Car has radiatior full of water when I left, and returned.
Valve on the head was open.
No leaks,
New water pump.

Should I blank off half the rad?

How about a new thermostat?
Assuming there is one in it at the moment.

Good call.

But the car ran faultless all day. Surely with 340 miles with a stuck stat it would show signs of overheating? I'll try removing it and see it it helps.

No - because they always fail OPEN = cold running engine. Fit an 82 or 88 degree stat for winter. The heater should be burning your left leg!

Don't remove the thermostat as it will definitely cause problems with the water circulation unless you fit what is called a 'blanking sleeve', but this is really for competition use only.

If the car is plumbed in the standard way, I would suggest that you make sure that the heater tap is fully open, get the engine up to normal temperature and while the engine is still running, loosen the engine end of the hose that returns from the heater, i.e. the one that is not connected to the tap. Be very careful as the water will be, or should be HOT!! Does anything come out of it from the heater direction? If yes, let it flow for a few seconds to 'bleed' the circuit, retighten the hose clip and see if the heater now works. If not then the tap may not be flowing water and needs to be checked.