hi, i noticed this morning that my hot water wasnt hot. i checked my timmer and noticed the fuse to the mains had blown so replaced it. re set the time and it worked fine... that is until it was "heating time" and a big POP in the wire connection housing of the pump. i looked in the housing to check inside and it was nice and sooty with the smell of burning. i took the electrical bit away from the pump to see the row of bayonet connectors and they were clean and not blackened.
so basically is my pump no more or can i just replace the electrical connector box? any idea what would suddenly cause this to happen after all these years or is just its time to go to pump heaven?
any help appreciated...

timmy, June 2013

I agree with oops! pump has seized up. new pump unit needed

dave e, July 2013

Dead pump.. Just buy a new one complete and change it. Don't Waste time messing with it.

Oops, June 2013

If the junction box (connector box) is all sooted up then that's where the fault occurred and for a guess a dead short inside the junction box directly connected live to neutral - there was a very brief flow of much current - great heat and then the external protective fuse blew - as it should.

If it were mine I would clean it up to remove as much soot as possible - give the enclosure and the wiring a very close inspection - concentrate of the bits where you see molten metal.

As long as there's no longer the rogue piece of metal that caused the short and as long as there's no carbon debris from the small explosion then you should be "good to go".

Your fuse sacrificed its life and died to protect the wiring - your pump should have been unaware of it all.

If by some chance the pump has been damaged (I very much doubt it) then you've nothing to lose by assuming it still good and trying it.

I would guess the fault to have been confined to the junction box and to have been caused by a small piece of metal - strand of wire - dropped connector screw or even an untightened screw that worked lose over time shaken by the vibration of the pump.

This is all guesswork...

Good luck...

Peccavi, June 2013