Hi,
Some weeks ago I asked about my Jaguar Combi which kept giving overheat fault messages.
Anyway - having had 2 CORGI engineers look at it, on both occasions it worked fine, so they couldn't diagnose the fault, although one said that the pump could be binding, thus causing an intermittent overheat as the hot water isn't pumped away.
So... each time I turn it on or up, I listen to the pump with a screwdriver.
The overheat occurs immediately if the pump doesnt run when the boiler fires up, and there is no immediate overheat if the pump is running when it fires up. It always eventually gives the overheat fault code, but I cant be sitting there with a screwdriver in my ear 24/7, so I dont know if the pump is stopping before the overheat.
It is therefore my guess that either
1) The pump is knackered and needs replacing or;2) something is intermittently sending a signal to the pump not to run - which doesnt solve the problem
Is 2 possible? or is 1 highly likely?