Heating fused

[billybargain]

Hi,

I have a potterton prima 60c boiler connected to a centreplaus c27 timer and a Landis & GYR stat.

When I turned the stat down to 'off' it clicked and the 3amp fuse blew. I've tried turning the stat back to on and replacing the fuse but it keeps blowing.

Any suggestions?

Cheers
Brett

 

[kevplumb]

check the stat wiring

 

[billybargain]

check the stat wiring

Thanks Kev,

The stat has:

: yellow cable in live which connects to a piece of choc block at the timer
: blue cable in 'off' (labelled off) which connects to the 'N' block of the timer with the other blue cables

:red cable in N (labelled on) which connects to 'L' block of the timer

This installation has been working for the past 2 months but I'm not sure that the thermostat has been touched in that time.

The timer diagram is http://www.screwfix.com/sfd/i/cat/pdfs/82/p3133382.pdf (I'm going by the Gravity Hot water with pumped heating via roomsat)
Thanks for any guidance

 

[picasso]

what model of room stat have you got ? it doesnt look right from what you have posted, on ,off and live seems to me to be a 2 wire stat (the off isint normally used) and if it is there shouldent be a neutral connected, post back the model number.

 

[electronicsuk]

what model of room stat have you got ? it doesnt look right from what you have posted, on ,off and live seems to me to be a 2 wire stat (the off isint normally used) and if it is there shouldent be a neutral connected, post back the model number.

As above, almost certainly as neutral connected to the 'heat satisfied' terminal, which you will need to remove and isolate in a piece of terminal block.