Honeywell MS921 won't go into programme mode

[Nixie]

Hi, I'm trying to bind a replacement 921 thermostat to an existing receiver. The receiver LED flashes as it supposed to do, but pressing (together) the up and down arrows, with the left arrow (after switching the stat to "Off") has no effect.

(Edit: When I say "Programme Mode" in the title, I don't mean Time/Temp/date programming)

I tried to factory reset the stat by holding down the i button and left and right arrows, again to no effect. It just ignores me!

The stat came from a working system so I have no reason to doubt it is functioning.

Any suggestions will be gratefully received.

TIA

 

[Nixie]

Another mistake. In the title it should say CMS921

 

[picasso]

You have to clear any stored data, did you follow number 1 ?

 

[Nixie]

Thanks for your prompt response Picasso. I'm pretty sure that's exactly what I did with the relay box, but the second set of instructions, 4 & 5, differ to what I was led to believe. I'll go back to the instal and have another go.

Thanks again.

 

[Nixie]

Nope. Tried exactly as described by Picasso and the thermostat does nothing. I had to re-bind the old stat (reason for changing - most of the digits are "out", a common problem apparently) and this method worked first time, (I could just about make out the word "Binding").

Is there a way to "Factory Reset" it?

TIA again