3 Amp Fuse to Heating keeps blowing, why?!!

[drpepperlover]

Great site. really good.

i've got a problem, don't know if anyone knows the answers or a possible cause to it- the fuse (3amp) to my central heating and hot water circuit has blown. i don't know what caused this... but after putting a new one in, it shortly went again. why is this happening? can't be dodgy fuses surely? is very puzzling!!




with a sealed central heating system, do you need to balance radiators or is just leaving them fully open sufficient as under higher pressure?? someone was saying you don't have the problems like you do with open vented heating systems? any truth in this?

 

[oilman]

There is a fault in the heating system. Fuses require twice their rated current for 30 mins to blow. More for shorter periods. Could be burner motor or circulating pump.

with a sealed central heating system, do you need to balance radiators or is just leaving them fully open sufficient as under higher pressure?? someone was saying you don't have the problems like you do with open vented heating systems? any truth in this?

Someone is wrong. All systems need balancing to work properly.

 

[drpepperlover]

thanks for the help-so it could be a filed pump casuing the circuit to overheat? i'll test the pump now and see if it is working correctly and spinning properley.

what burner or motor do you mean?

 

[dal5band]

Fuse - look for any small damp problems in / near the boiler electrics. May be a small drip somewhere onto a connector or something. You can normally see the electronics without removing the combustion casing which of course is a qualified gas job.

Balance - the higher pressure means you don't get too many air-lock problems. The radaitos still need balancing - the whole system is at the higher pressure so is nothing to do with balancing radaitors. There is still a pump which provides the flow pressure which varies dpending on how far each radaitor is from the pump. Turn all the lockshiled valves about half way then each day turn the radiators that get hot first donw a bit and the colder ones up a bit.

 

[gas4you]

It would help immensely if you told us exactly what type of system you have including boiler make/model.

All we can probably guess is that it is gas, having only a 3 amp fuse

 

[drpepperlover]

boiler is potteron flamingo

system has header tank in loft 2 floors above.

pump and diverter valve are in airing cupbaord in bathroom next to hot water tank.

thanks for helping.

 

[granty1]

its most prob ur pump nw to check this ur turn power and take live out of pump and put it in to a connector block, then turn power on, ul find that the fuse wont blow,

 

[namsag]

LOOK around pump /valves for water leak or anywhere else it could possibly drip into the motorised valve ,

 

[drpepperlover]

sorry for the gap in replying.

thank you all for your help.

there doesnt seem to be water around anywhere.

will this pump test prove that the pump is failing? why is it blowing the fuses though, i thought usually pumps just seize up and fail?

 

[kevindgas]

pump causes fuse to blow when motor is shorting the test suggested is the quickest way to verify wether the pump is the problem

 

[poolebybirth]

This is rare but the pump can have a problem with its capicitor/internal electric workings which cause it to blow the 3amp fuse and the whole power to your heating (and hot water in your case)!

if the test proves successful, you will need a new pump.

most pumps are the same or very similar dimension sizes, so if you can afford about £60-65 buy a Grundfos. The best pumps IMO. You will probably need the 15:50 type and not the 15:60 (which is for larger properties usually, or those with more rads!!)

 

[drpepperlover]

thanks for your help.

one point though, when you say put the live wire from the pump in a separate termianl block, do you mean the LIVE wire from the pump terminal or the LIVE WIRE from the wiring centre terminal side?

Also, do you mean put it in a lose connector block/strip, that is not in the wiring centre?

I can do this, and have the strip, just wanted to clarify so i get it 100% correct first time!!

 

[Soggy_weetabix]

Perleease... just get on with it....

Isolate the power to the heating system, pull the live out of the pump and make it safe.

Turn the system back on and provide a call for heat. (once you have replaced the fuse).

It will take you 2 minutes.

 

[drpepperlover]

sorry mate feel like an idiot now!!!!

just did it and yes the pump works and the fuse did not blow this time!! so the pump is the victim then? why is this-whats the cause out of interest?

new pump time?...

 

[oilman]

why is this-whats the cause out of interest?(

I'll just have a look..................