I have an Aqualisa Aquavalve 605 in the house we have just bought. The unit is outside of the warranty period and has developed a leak from the back of the unit. The water is not coming from any of the pipes jointed into the back (i.e. the body) of the unit, it is instead coming from the centre of the unit itself.

Any ideas what may have gone awry here? The construction suggests to me that it may be the "Gasket with filter" which I think provides a seal to the cartridge. However I have read a number of posts which suggest it could also be the cartridge. Any ideas which it is likely to be or "tests" which would indicate which part was at fault.

Any help anyone can give would be very much appreciated. As you can probably tell I am clearly a novice!

Thanks

Gary