3 amp fuse blowing on heating

DEVEREUX

Hi there,

My heating went yesterday topped up with oil today.

Bled the burner, didn't start at first..I noticed when i moved the electrical junction box the fan came to life and it fired.

Power went then with the 3 amp fuse blown in the kitchen beside heating controls.

I isolated the pump same problem no power. Isolated the stat on boiler and this time I have power to the heating controls but not it seems to the burner.

I had a spare stat and went ahead and replaced it but still same issue.


Any suggestions to what the problem is from info above?

Thanks

Dev

DEVEREUX

Sorry I should have added it's an external grant oil boiler with a reillo burner

K.Flyer

Check the wiring circuit.
If something happened by moving the box, then it is likely you have an electrical short that blew the fuse.
Do not be tempted to use a higher rated fuse than 3 amp as this could result in more damage occurring.

Dtp1979

K.Flyer wrote: »

Check the wiring circuit.
If something happened by moving the box, then it is likely you have an electrical short that blew the fuse.
Do not be tempted to use a higher rated fuse than 3 amp as this could result in more damage occurring.

If it's oil then it should be 5 amp. But even at that, the 3amp shouldn't be blowing

DEVEREUX

Thanks for replies I've checked and tightened all connections.

Same thing happening when I come back to house and turn power back on, the fuse blows immediately.

So when I isolate the boiler limit stat the fuse doesn't blow, the pump is active, heating controls are on, the motorised valves work in the hotpress but the reillo rdb burner is dead.

Fault on the burner?, motor? Does the burner need the boiler stat to energise

Please see pic for wiring setup

Thanks again

Wearb

Does that thermostat need a neutral?

DEVEREUX

Wearb wrote: »

Does that thermostat need a neutral?

Why do you say that? It's a TLSC type 07050


Stat wiring diagram attached

Wearb

I don't understand that stat diagram. It looks like it is wired to cause a short circuit.
I must be reading it wrong, perhaps someone else will explain it.

Dtp1979

Wearb wrote: »

I don't understand that stat diagram. It looks like it is wired to cause a short circuit.
I must be reading it wrong, perhaps someone else will explain it.

As far as I know, that stat doesn't need a neutral either

Robbie.G

DEVEREUX wrote: »

Why do you say that? It's a TLSC type 07050


Stat wiring diagram attached

That stat does not require a neutral if you have a neutral connected that's what's blowing fuses

DEVEREUX

I'm confused now as this wiring setup has been untouched for 6/7 years since installation....I'll pull the neutral tmrw and report back.

Thanks again for all replies

Robbie.G

DEVEREUX wrote: »

I'm confused now as this wiring setup has been untouched for 6/7 years since installation....I'll pull the neutral tmrw and report back.

Thanks again for all replies

You should have 2 neutrals there neutral in and n to burner join the two of them together in a separate connector not any terminals on stat and you should be ok also watch out for your earth