have I killed my CH Programmer?

[lavena]

Right - think I might have damaged my CH programmer (Honeywell, 2 program, digital).

I was replacing the room thermostat with a new digital one, and messed up the wiring, blowing the CH fuse . Have now put the original thermostat back - it still controls the CH pump BUT overrides the programmer.

E.G. with the programmer set to off (no CH, no hot water), the thermostat still turns the pump on and off.

The programmer still turns the boiler on and off correctly (as far I can tell) [although I'm sure the boiler is getting hotter than before, but suspect this is my "what else have I broken" fear getting in the way).

Any ideas?

 

[breezer]

It sounds like the internal contacts for the "programmer" are "welded" together, which was caused by you when you wired the new stat wrong.

The "programmer" cuts the supply to the pump as does the stat (when required) but as you say the pump will run when the stat says to run that indicates the programmer is stuck "on" Time (no punn intended) to get a new programmer

you can get a new one for £25.00 it uses "industry standard" back plate , which means no wiring to be changed.

try
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=11225&ts=02568

 

[lavena]

It sounds like the internal contacts for the "programmer" are "welded" together, which was caused by you when you wired the new stat wrong.

poop - thats what I suspected (stupid relays!)

I guess the only way of checking is to put a new one on. (Oh well - at least if I pay a premium at B&Q I can take it back if it something else).


OK - as you have been so helpful (thanks) - any suggestions about how I should have wired the replacement (two wire - has 3 sets of contacts though - NC, COM and NO) thermostat where I currently have a 3 wire thermostat (wired 1-yellow, 3 red (definitely live) and 4 blue)

thanks again,

J

 

[breezer]

It depend what the wires do. If red is live, i guess (and its only a guess) Blue is neutral and yellow is switch

To connect it to your new one you should connect red to Common, yellow to N.O (normally open, it closes when heat is required)

To find out what they all do do you not have a connection box / junction box near your programmer, Turn the mains off, find the stat cable and follow each individual wire and see what it is connected to, I would be inclined to check the blue first

 

[lavena]

It depend what the wires do. If red is live, i guess (and its only a guess) Blue is neutral and yellow is switch

Yup - from checking the schematic on the current thermostat thats it (also checked with a mains testing screwdriver)

To connect it to your new one you should connect red to Common, yellow to N.O (normally open, it closes when heat is required)

cool - so that means I just need to insulate the "spare" neutral.

thanks again - much helpfulness.

J

 

[breezer]

yes, just insulate the blue wire.