Electrical fault advice needed

[Jock Spanners]

I'd just finished a bathroom this afternoon and was walking out the door when the downstairs lighting circuit tripped and refused to re-set. I had just finished swapping the room thermostat so Im worried it's more than a co-incidence. It's a newish house so I don't think I've drilled a cable when fitting the WC. I had to leave it but I'm worried I'm going to get a call. Any ideas?

 

[hewie]

What electrics have you added or modified? Need more info

 

[Jock Spanners]

None - just changed the room thermostat - a straight swap. It was working. There's no sign of drips and if I drilled a cable it was at least an hour before it tripped.

 

[REDSAW]

or just after it switched on?.

 

[Jock Spanners]

Possibly - why should the thermostat affect the lightling circuit - they're not linked are they?

 

[REDSAW]

it could be earthing out somewhere.
if it were me, i would take the stat of, put the screw back in and test the screw for voltage, and of course check for dammaged wires near the case screws.
if not, it may not be your problem.

 

[Jock Spanners]

The new stat is only a two wire job with no earth. Would that matter? Surely the thermostat is linked to the programmer which is then linked to the boiler circuit not the lighting

 

[hewie]

As redsaw said, you might have screwed into a cable. Check first at the WC remove screws one at a time then try reset trip. Thermostat might not be the problem, sounds just live in and switched live out( sure there's no unused neutral curled up somewhere behind the wallplate). Does the CH still work with the trip off?

 

[rolo]

Just joined and posted a question and noticed this,I'm a sparks.
Check whether the boiler is on the same circuit as the tripped lighting circuit,if it is then i'ts likely to be something you've done changing the stat,if not i'ts not your problem as long as there are no other cables around the stat.

 

[Jock Spanners]

Cheers Guys,

It turned out to be a faulty strip light (the ballast) and a faulty (new) thermostat. The sparky fixed it in no time. At least it wasn't me!

 

[Renewable M]

You have had a result there!