circulation pump blowing fuse ?

[mac27]

i have main fuse keep blowing on my central heating system could this be the pump ?...ive changed the acuator and Stat ! but it keeps on blowing the main 5amp fuse (in the fuse box)after 5 minutes after switching on ! any ideas !...the pump feels cold when the heating system fuses after being on for 5 mins ! ..so can the pump still fuse the electrics even after 5 mins /?

 

[PrenticeBoyofDerry]

A fuse can blow over a period time, it relative to the value of the fault current over time and the capacity the fuse has to maintain that particular fault current.
A fuse blowing could be for a number of reasons, to track it down you would need to eliminate electrical connection of the circuit and/or do some electrical testing.

 

[picasso]

Why have you started another thread on the same problem ?

 

[mac27]

Why have you started another thread on the same problem ?

Apologies but i wasnt sure if my problem was for the Electrics forum or Plumbing and Heating forum and mistakenly put it on here first ....and this is my first post on Diy Not

 

[stem]

i have main fuse keep blowing on my central heating system could this be the pump ?.

It could be but it could be anything connected to the fuse. Boiler, Motorised Valve, damaged cable etc., unless you have electrical test equipment and know how to use it, all you can really do is adopt a trial and error approach and install a new pump and see.

Having said that, if you can do this safely, you could disconnect the pump from the existing wiring (insulate it and make it safe) then wire the pump to a 13A plug with a 3A fuse in. Switch the boiler off and manually open any motorised valves to allow water circulation, then plug in the pump and see if it blows the fuse in the plug. If it does the pump is faulty.

but it keeps on blowing the main 5amp fuse (in the fuse box)

This is unusual, normally the heating system is connected via a local fused connection unit with a 3A fuse in.