Vaillant Ecotec pro Baffled?

Just observe it's rotation when you take it out, it only goes back in one way, if you get it wrong, you won't be able to refit the flow connection to the manifold.

Carefree
October 2011

Thanks carefree ... altho I did take the water pressure switch out ...and notice the filter was clean ...but maybe it was blocked on the outlet to the plate to plate not sure .....but gonna strip it down to look ... will keep you posted mate ...other chap that came before me put all the new parts on ...

SEBO
October 2011

Had this very problem last year, it was a blocked filter due to an unclean system, the same symptons, pre-heat would run but H/W demand would push heat down the C/H flow.

Test by turning off the C/H flow isolation valve, run the H/W (not pre-heat), if the filter is blocked, the temperature will rise rapidly until it reaches about 85c then shut the flame off, it will then stay off until the temperature cools sufficiently and will run through the process again.

The filter is located in the bottom brass L/H section of the boiler, if you take out the C/H pressure switch (older models), you will see the filter in behind through the hole. It is extracted to the left after removing the flow connection to the brass block.

Carefree
October 2011