Grundfos pump still not working

[Funkyfridays]

Recently had grundfos ufh pump not working, found circiut board on terminal box on side of pump burnt out. Changed pump but still not working? Feed is live from slave unit into pump but no lights on side of pump? There is a block on the wire which leads to the pump but it is sealed, could this house a fuse? any ideas? Thanks

 

[Echo the husky]

Is there power at the pumps terminals?

 

[Funkyfridays]

Yes

 

[Funkyfridays]

Theres power at the pump and the terminal but no light where the 3 speeds are which im sure there was before the fault, the pump is brand new? Thanks again

 

[ollski]

Turn off the power and remove live and neutral wires from the terminal box and check resistance with pump connected. Should get about 200 ohms. If you do pump and wire ok. If you get infinity / OL remove live and neutral pump end too and twist together and test as before, if you get couple of ohms then wires fine and pump is shot, if you get infinity / OL then it's the wiring. All with power completely isolated!

 

[jeff the gasman]

Are you measuring voltage with a neon screwdriver by any chance?

 

[Funkyfridays]

I was yes, think ive got it tho, open circuit on live on the wiring, live was in half inside that sealed housing i mentioned, hopefully a new cable kit should sort it thanks

 

[Echo the husky]

Are you measuring voltage with a neon screwdriver by any chance?

I did wonder, a neon screwdriver wont detect a missing neutral.

 

[Funkyfridays]

Help! Ordered and fitted new suppressor lead which i found was faulty but pump is still not working and has no lights on but power at the pump,

 

[jeff the gasman]

FFS. game over. Call the army.

 

[Funkyfridays]

Im starting to wonder has it always been like this since i moved in because i put the floor on and it gets hot yet im sure the pump never comes on as ive never heard it, it gets red hot and theres no lights on it as tho theres no flow through it, how often should the pump be on on average? Im pretty sure this is why the last pump and lead burnt out but ive now changed both and its still the same? Where should i look next?

 

[Echo the husky]

Was the entire pump changed, or just the motor? Does the shaft rotate freely through he bleed screw?

 

[Funkyfridays]

Yep the pump spins freely, i only changed the terminal box on the side and lead as that was what was burnt out but but not the pump. I had to buy the pump because it comes with the terminal box so i have tried plugging the new pump in whilst not plumbed in and still no lights or doesnt spin?

 

[Echo the husky]

i only changed the terminal box

But you used the old motor? The motor windings could be faulty killing the old electronics, now hew new electronics could be dead.

 

[Funkyfridays]

No although ive a new complete pump and terminal box i only changed the terminal box and still no good so i plugged tge new terminal box into the new pump without plumbing it in and still no lights or doesnt spin?