friday 5.00 help needed

[underpar12]

hi guys been called to a plumbers job ,system s plan he was just fitting bolier change valiant eco ,he connected both cables l,n,e flex one to mains intake and removed link and the pump into the terminals. as soon WE TURN ON the fuse spur the 3amp fuse blows instantly, nothing else has been touched . i checked the correct mains conections etc all ok. removed time clock ,still blows 3 amp . iam thinking fault was already present before bolier was swapped. any help ,

 

[telectrix]

faulty pump?

 

[bugsy]

Has he taken a supply shared with the water heater by any chance?, you don't say what controls are involved , ( built in or remote )

 

[underpar12]

thanks for reply,
the supply is a fuse spur on the up ring main , the immersion is on separate m,c,b.the controls our not wireless if that's what you meant .

 

[bugsy]

I can only suggest you check the zone valves and pump - if all the wiring is as is I cant think of anything else unless he was playing with it before he called you