Thought I would investgate why the heater started to leak when the wfp was turned off before I binned it.
Turns out it was leaking where the pipe is squashed down where the sensor it fitted. To find out where exactly the water leak was coming from I ended up having to dismantle it completely and take it out of the case. That was a challenge to say the least what with me shakes and all. 22 screws later and a load of wiring disconnected I'm not convinced it will go back as it should either. lol
Anyhow as I wanted to continue to have a play I put on some evo-stik metal epoxy putty to try to fix the leak. Thought it had whilst still out of the case but as soon as I kinked the outlet house it started leaking again. Now I've just put on some more so will see how that goes at fixing the leak.
Must say though the heater ran sweet for yonks before this problem so I'm guessing after a while a weakness develops in this particular type heater. Mind I maybe just unlucky as the hot water outlet pipe did look dodgy when I bought it as was out of aliment compared to the inlet. lol