Adding RF room thermostat

[Jonsey123]

Hi,

Hope somebody can help. I have an Ideal combi boiler with a Drayton LP111 timeclock installed. This works fine, but does not have a room thermostat. Not sure why this was done, as the previous occupants had this installed. What i would like to do is add a RF room thermostat either to the current system or to find the most cost effective way to replace the system.

Help much appreciated!

Cheers

Jonesy.

 

[namsag]

Should be straight forward , what ideal combi is it and if poss picture of boiler wiring instructions

 

[Jonsey123]

Hi,

Its an Ideal ISAR. Manual is here:

http://www.idealboilers.com/docs/html/isar_he_manual.html

 

[D_Hailsham]

You could keep your LP111 and add a Honeywell Y6630D wireless stat for about £70 or you could ditch the LP111 and replace it with a Honeywell CM927 wireless 7-day programmable stat for about £90. Wiring is easy. Boiler Terminal L1 is a 240v supply and L2 is the switched return. You will probably find that your LP111 ON terminal is just connected to L2 and L1 is not used.

The receiver of the wireless stat, which is the same for both Honeywell models, needs a permanent mains supply to the L and N terminals.

If you retain the LP111, connect the CH ON terminal to terminal A of the receiver and connect terminal B to L2 on the boiler.

If you ditch the LP111, link the L terminal of the receiver to terminal A and connect terminal B to L2 on the boiler.

 

[Jonsey123]

Hi D_Hailsham,

Perfect, thanks for the response. Just one question, can i use L1 as a supply to the wireless stat receiver? Or is that not a permenant supply?

Thanks!

 

[D_Hailsham]

Just one question, can i use L1 as a supply to the wireless stat receiver? Or is that not a permanent supply?

Seems OK to me, but don't forget that the wireless receiver also needs a Neutral, which can come from N.

 

[Jonsey123]

Hi again, the plot thickens. The back of the boiler is not accessible (worktop below and encased in a cupboard). So I have taken the digistat apart and i have power and number 3 connected. I think that means that in order to install the Honeywell, i need to remove the whole boiler (£££).

I have been looking into other options and wondered if anybody could confirm if replacing the current digistat with the new digistat 3 +RF would work justing using power, earth and terminal 3 (call for heat)?

If so, i can program each day and have a room thermostat without removing the boiler.

Cheers.

 

[D_Hailsham]

The back of the boiler is not accessible

Why do you need to access the back of the boiler? You can get at the electrics by removing the front cover.

So I have taken the digistat apart

What digistat? You haven't mentioned a digistat previously! According to you opening post you do not have a room thermostat and were considering buying one!

i have power and number 3 connected.

what are you talking about? It does not make sense.

 

[ChrisR]

Just do this:
View media item 4902

 

[Jonsey123]

Hi D_Hailsham,

Apologies, i am getting myself confused. All cables go into the back of the boiler (which i am unable to access). I didn't realise you can get to them from the front!

Replace digistat with timeclock / LP111.

L, N and terminal 3 on the timeclock are currently connected, my question was can i achieve what i want using only these three cables.

Chris, thanks for the post, looks like i should be able to cable the wireless stat using the three cables present in the timeclock.

 

[D_Hailsham]

Replace digistat with timeclock / LP111.

Do you mean: ditch the LP111 and replace it with a digital programmer/thermostat?

If so, you can use the existing three wires - provided the location for the wireless receiver, which will replace the LP111, has good reception from the transmitter/programmer. You can use just the three wires.

L, N and terminal 3 on the timeclock are currently connected

L to L
N to N
T3 will be the switched live to boiler L2. Connect it to the switched live on the new programmer.

You will probably have to insert a link wire between the L terminal and one of the switch terminals on the receiver to provide the power to the volts free switch. (see digital programmer instructions)

 

[Jonsey123]

Spot on, thanks D_Hailsham.