New thermostat..blowing boiler switch fuse

[TheEsoo]

As per title, having had a new thermostat fitted, whenever the heating goes to run, pop goes the fuse.

Any ideas? Picture attached.

Apparently it's a three wire installation.. but there's four

 

[EFLImpudence]

Well,
3 is Switched Live and
2 is Neutral

So it appears that they are the wrong way round - assuming whoever did it hasn't done the same at the other end - but then it wouldn't trip.

 

[TheEsoo]

Thanks, switching them round should sort it?

Here's the instructions btw

 

[CBW]

Well,
3 is Switched Live and
2 is Neutral

So it appears that they are the wrong way round - assuming whoever did it hasn't done the same at the other end - but then it wouldn't trip.

assuming they have used blue as Neutral?

Op - what boiler is it?

 

[TheEsoo]

Gloworm ultracom 15?

 

[CBW]

Gloworm ultracom 15?

Just making sure it’s not the boiler pump.

 

[TheEsoo]

All working now, much appreciated