Replacement of room stat an cw and hw programmer

[jnix]

Hi,

I have spemt the afternoon installing a new programmer and room stat and have hit a snag on testing.

The HW works a treat, as does the CH, with the exception of the room stat heats up when it is set to a temp lower than room temp and doesn't when set higher, eg 32 degrees.

I'm confident all is wired correctly, so could the stat be faulty, or what could the problem be?

Thanks in advance.

Joe

 

[Youllneverguess]

with the exception of the room stat heats up when it is set to a temp lower than room temp and doesn't when set higher, eg 32 degrees.

say that again in English...

Are you saying when you turn the stat up the boiler comes on?

If so then you haven't wired it up correctly.

What thermostat have you used?

 

[jnix]

The boiler is always on for the hot water (HW). The central heating (CH) comes into play when the pump is turned on via the room stat. However the room stat turns the pump on when it should be off, i.e. when at say 10 degrees, when it is turned to 30degrees the system the turns off.

The room stat is wired to a junction box with live from the programmer to the stat, which when the stat is on it flows through a yellow cable into the pump as live (via another port on the junction box).


I have a back boiler system and have wired up according to Siemens RWB29 Programmer via a 10 way junction box. I have a Honeywell DT90E stat.

Thanks for the quick reply.
Joe

 

[Youllneverguess]

Are you sure the wires in the stat are in terminals A & B rather than A & C?

 

[Youllneverguess]

And by sure, I mean go and have a look.

 

[jnix]

You are a star, it has had me stumped for a while. The stat was put in a few days ago! So I assumed it was something I had done today!

Solved! and thanked!

 

[Youllneverguess]

Glad it is solved for you.