Wiring a thermostat. Any help please?

[paterson00]

Does anyone know how i should wire my new thermostat in. Here is a photo of the old wiring and the new one.?

http://www.flickr.com/photos/21472212@N07/2909621463/

http://www.flickr.com/photos/21472212@N ... otostream/

[Jimbo]

Old stat is a 3 wire, sooooo, Earth is earth, then we have a neutral,load and positive. I am not going to guess at the way yours is wired but normal would be blue is neg, yellow load and red positive. If you have the cover from the old stat look inside it normally it shows the configuration. On to new stat this is a 2 wire drop the neutral (otherwise big bang) earth is not needed but maybe used for continuity. So that leaves pos and load all you have to decide is if its NO (normally open) or NC (normally closed) some boilers will have a link and you just have to remove the link and put the two stat wires in. ONE THING. make sure you dont use a mains voltage stat where it calls for a low voltage one. Expensive game. I apologise if any of this explanation sounds condescending I have no knowledge of your level of expertise. Regards Jimbo

[paterson00]

Thanks very much fo your reply. Im a railway electrician / technician so im used to wiring things up but not immensly great at the principles behind it. I can install a safe job if someone tells me what to avoid and you have, many thanks.

I have already wired the stat into the system and it still does not have any affect on the temperature controls. Maybe i have wired it incorrectly? Or maybe there is aother problem elsewhere. Maybe i should point out at this time that... I have a gas fire with a back boiler and at the moment the only way i can get my radiators to come on, and also the only way i can control the temperature they produce is by turning the control dial which is under the fireplace in my front room. To do this i have to lay on the flor so i know that that is not how the system is designed to be used.!!! Does this give you any clues as to why i still have no joy? Perhaps i should alter the wiring on the stat so that i go into the other NC / NO terminal? Ill try tomorrow.

Many thanks again, and i would be realy gratefull if you would cast your opinion on my system. If you would like i can take a photo of the fireplace and back boiler with its controls. Its a Baxi Bermuda.

Thanks again