Fuse blowing help

[andersH]

Hello, moved into a house around a year ago and there is a bit of a problem with the central heating, bear with me as I'm not really knowledgable on how it all works! I can feel a click in the thermostat when I turn it (I presume that this is the click for what the temp is at the time?) If I turn the thermostat past this click (currrently around 13º) then the 3A fuse for the electronic timer will blow. If I turn the thermostat down past the click again and put a new fuse in all is fine. Any Ideas?
I have attached pictures of the 2 devices in question if it helps.

 

[LUNAT]

HI

1.open room stat cover check loose wires
2.remove programmer (not the base) check loose wires
3.check all accesible places for any live wires touchig metal,earth wires,etc.

 

[corgiman]

When did the room stat get changed?

 

[baxpoti]

Disconnect the pump.

 

[andersH]

All connetions seem ok to me - I may redo them just to make sure at some point. The thermostat was there when I moved in and have no idea how long ago it was installed I'm afraid. I have added more pictures of the wiring:

 

[gremlin16]

Earth used as switche wire

 

[andersH]

Ok, by the sound of Gremlin16's post this isn't a good thing?! Apparently the person who lived here before was an electrician and there were lots of interesting things going on when we moved in!
So is this all wired up incorrectly then? I really don't have any knowledge of how it should be.
Cheers.

 

[namsag]

Do you have motorised valves .picture of those and pump may help

 

[gas4you]

As Gremlin says and assuming he is correct, each time your room stat calls for heat 240V will be sent down the earth so blowing the 3 amp fuse.

You need to find out which earth from the room stat it is at the programmer box and remove this.

Earth used like this should be sleeved with brown sleeving to show they are being used as a live phase.

 

[LUNAT]

HI

N.3 on the room stat is it just the sleeve or actual earth wire used ????
if earth wire is used then who the hell did that?????

 

[namsag]

Nothing unusual about wrong coloured wires being used on heating circuit loads of it out there. Not right but common

 

[ollski]

Are you saying the hot water works ok but the heating doesn't?, what sort of system is it?. pics of the valve would help.

 

[Soggy_weetabix]

Get the pump disconnected (as Baxpoti has suggested)

Dave

 

[andersH]

It does seem to be an earth wire going to number 3 on the stat.
The thing is, even though the stat is at around 13º the heating does come on and the radiators do get pretty hot. The other thing is that the hot water switch turns the water and heating on and the heating switch does nothing!
Not sure what all the parts are that are mentioned, is this the valve?

 

[andersH]

Get the pump disconnected (as Baxpoti has suggested)

Dave

Sorry, I don't know what the pump is or looks like