Thermostat help

by **andykb** » Wed Dec 14, 2011 10:22 am

Hi,

I have a Honeywell 4 wire mains stat(earth, blue, yellow & red) i recently moved it and wired it incorrectly and trip my rcd.
I got the yellow and blue the wrong way round...MY BAD..!

Anyway surprisingly it no longer works and i cant hear a 'click' when turned plus my heating is on constantly!

Is it likley to be just the stat or have i shafted something else?

Please dont mock me

Andy

by **plumbbob** » Wed Dec 14, 2011 9:58 pm

My guess is you have connected the neutral (blue) to the live and welded the contacts together. With luck that is all you have done.

Manually join the yellow and red together and the boiler should (hopefully) fire up.

by **andykb** » Thu Dec 15, 2011 8:26 am

Hi bob,

ive reconnected them as per a neighbours and the boiler fires all the time, i have to switch it off at the wall. I'm just wondering if its worth spending the cash on a new stat or a £99 BG call out to have a look/fix

andy

by **plumbbob** » Thu Dec 15, 2011 6:05 pm

andykb wrote:Hi bob,

ive reconnected them as per a neighbours and the boiler fires all the time, i have to switch it off at the wall. I'm just wondering if its worth spending the cash on a new stat or a £99 BG call out to have a look/fix

andy

Well. that's up to you, but if the boiler is firing then at least that must be ok. If the red or yellow wire is disconnected from the thermostat then the boiler should stop firing. Does it?

by **andykb** » Thu Dec 15, 2011 6:48 pm

decided to strip the stat down and the contact were fused together freed them off and im back in business!! what a relief still gonna go for a new stat though any suggestions for a wired one?

Digital would be my preference!

by **andykb** » Thu Dec 15, 2011 10:15 pm

ok bit of an update i can now switch the boiler on and off via the stat but the boiler does not seem to be 'obeying' the honeywell timer controls, the ones that fire the boiler\hot water on & off in the morning\afternoon

im thinking the timer could be stuffed??

by **plumbbob** » Thu Dec 15, 2011 10:23 pm

It may be the contacts have welded together the same as the thermostat. The trouble is they are not as easily repaired as the thermostat was.

Don't forget the boiler may have a pump over run so may not switch off the moment the timer turns off.

by **andykb** » Fri Dec 16, 2011 12:17 am

the contact on the timer box on the wall?

by **plumbbob** » Fri Dec 16, 2011 7:40 pm

andykb wrote:the contact on the timer box on the wall?

The Honeywell timer you say is no longer controlling the boiler.