DIY Doctor UK DIY Forums

Hi

Wonder if anyone can help. my Grundfos selectric 15/50 pump has started to make a strange "crackling" type noise. The CH and HW seem to be working OK it's just this noise has started.
I don't know how old the pump is so maybe it's telling me it needs replacing -I've taken the front bit off and the pump is working. I had the motorised valve actuator above it replaced last year.
Anyone have any thoughts- or is it just going to get worse and need replacing
(Also possibly a daft question but are you supposed to be able to have either just HW, just CH or both on only I can only have HW or bothon)
Thanks
C

if its a 3 port motorised valve, then yes you should be able to have water or heating or both on, The noise coming from the pump may be a loose impeller or maybe some sort of sludge build up in the pump. Strip out the pump head and check for a any crap build up and check impeller isn't loose, if still making the noise change the pump (about £60 to buy)

Thanks
I'll give that a go.
It is a 3 port motorised valve that is fitted, but I've never been able to have CH on w/o HW on. Is that likely to be a fault or the way my system is set up?

its possible that wrong programmer has been fitted, or if you remove the programmer, there should be a switch on the back, for gravity or pumped HW switch it across then see if the heating works by itself.