30cdi plus BPS242RF heating issues

[Phil_188]

Hi im new to the website but hoping someone may be able to help. Hopefully I've put the post in the right location. I currently have a 30cdi Worcester unit c/w wireless stat BPS242RF. The stat is set so heating comes on from 5am to 6.30am and from 4.30pm to 9.30pm. The issue is that even with these settings the heaters are continuing to be on and the system is controlling temp to the max 18c set point. This is even when the stat says the system should be off. Does this sound like a stat issue? I've tried resetting and also changing batteries in the thermostat, none of which help. If it is the stat can you reccomend any replacements? Thanks

 

[tamz]

Nah the other 10% were binned on the job :smile:

 

[Phil_188]

The frost stat was at about 2-3 so I've turned that up to 6. I've just bought the Honeywell cm927 as we have been after one with more functionality anyway. Will try tonight/tomorrow and see if anything changes.

 

[Phil_188]

Got the thermostat fitted. Really good with a lot more options/settings. Really happy with it. I checked the frost stat and am getting live at both terminals.

 

[tamz]

You should only have live at one terminal of the frost stat. If it is live on 2 it means the contacts are closed (it is switched on).
Try turning the frost stat down and see if it breaks the switch.

If it won't break you need to replace the frost stat.
Btw a CDi has built in frost protection which will protect the boiler.

 

[DirksPlumbing]

1.We use a lot of wireless equipment in the home now and have recently had a bt hub fitted for broadband. WOuld this cause any issues that you know of, and would it be better to get a wired version of the cm927 stat?
2. At the moment out Boss therm stat is also connected to a Honeywell frost stat. Does this complicate the wiring if i rewire the new stat myself or is the wiring pretty easy to follow?

As mentioned the CM927 does not appear to interfere with other equipment. The CM907 is very easy to wire if a suitable route for the cable exists. Both require AA batteries anyway.
I tend to wire them on older boilers in the frost stat port as this guarantees that no internal clock does interfere with them and they provide a frost stat functionality themselves.
The only contra indication for doing so would be boilers that limit the flow temperature for the frost stat demand.

 

[Phil_188]

Stat now fitted, programmed but still getting same results. Opened the frost stat as per previous comment. I have turned the stat down to the minimum and both contacts are live. On Turning the stat down a click is heard at approx 4C but terminals still live.

 

[tamz]

Stat now fitted, programmed but still getting same results. Opened the frost stat as per previous comment. I have turned the stat down to the minimum and both contacts are live. On Turning the stat down a click is heard at approx 4C but terminals still live.

You need a new frost stat, they cost about a tenner or cut it off and either pull the wires or terminate them in a box (separate). Your boiler has built in frost protection so it will be fine. Your pipes may need it but that is your choice.

 

[DirksPlumbing]

If you are going to replace the frost stat it would be a good time to add the bespoken pipe stat onto the system.

 

[leethegasman]

I agree so many frost stats out there without pipe stats

 

[Phil_188]

New frost stat is fitted so will see what happens. Heaters are off now which is a good start so heres hoping! Could someone double check the wiring below if possible. Think its right.

Oh and i was thinking the old thermostat i replaced with the Honeywell one for more functionality is probably okay, so if anyone wants it let me know. Thought id ask cause everyone seems to love them!! ha ha

 

[dancinplumba]

where is your brown sleeving on the blue wires to the right ?

 

[vern]

Aww the old frost stat problem.....thought so....yep wiring is correct as long as perm live is on left and switching pair on the right

 

[Phil_188]

Looks like heating is coming on/going off when it should now, so thank you very much to you all for your help. Very much appreciated!!! Especially with the current weather.Thanks again. Phil

 

[tamz]

Remember the brown sleeving on the switch wire :wink: :lol:

 

[Phil_188]

Will do! I need to redo most of the wiring as I just roughly twisted them to get it fitted quickly. Thanks Tamz, Vern etc for all your help and remember I've got a boss therm if you want! You know you want it!