Morris Minor Owners Club

I've just replaced heater pipes on an 803 and fitted a reconditioned circular heater unit. The lower pipe from the tap at the rear of the cylinder head very slowly gets warm but the top pipe remains cold. Could this be an indiocation of a faulty water pump?

Or a blocked tap - or kinked hose. Did you run a hose through the heater to check it's not blocked? And the return pipe to the rad - is the connection clear?

Ha, Ha. I've worked it out. I had removed the old (leaking) heater unit and fitted the new pipes to the new unit exactly following the original set up.Should have double checked against the workshop manual - pipes had been installed the wrong way round on the old unit - which is why it probably didn't work before.

Doesn't matter a monkey's which way round they go.......

Although it might not matter which way the hoses are connected, the BMC Workshop Manual is quite specific about which hose should be connected to which connection on the heater, whether it is the early round type or later fresh air one.

I would think that you may have had an airlock the first time that was cleared when you changed the hoses round.