Wiring Wireless Stats : Honeywell CM927 & Siemens REV24R

[infrequentuser]

I am considering replacing my current wired stat because it is not located in a good location : it is above a radiator in a fairly cold & drafty hallway.

It seems to me that the easiest way to replace the current stat would be with a wireless stat by wiring the new base unit or 'receiver' in the location currently taken by the wired stat. The Heating Programmer to be kept switched '0n' permanently. Then I can use the wireless transmitter in a better location.

Before I purchase a wireless stat Iwould like to be certain that I know how to wire it up.

The current wiring in place in the hallway is as follows :

3-core-and-earth with old colours - Red (I believe 'Live'); Blue (believe 'Neutral'); Yellow (believe ' Switched Live') and "Bare" (believe 'Earth').


I believe the wiring for the two wireless stats which I'm considering should be as follows :


1) HONEYWELL CM927


Yellow → Terminal B

Red → Terminal L
Blue → Terminal N
Earth → Back Box only

+ Short piece of Red wire connecting Terminals L and A


2) SIEMENS REV24RF


Yellow → Terminal L1 (N.O. contact)

Red → Terminal L (Phase)
Blue → Terminal N (Neutral)
Earth → Back Box only

+ Short piece of Red wire connecting Terminals L (Phase) and Lx (Phase)



Is my proposed wiring for the CM927 and REV24RF correct ? I would be grateful for confirmations.

Thank You

 

[seco services]

1) HONEYWELL CM927

2) SIEMENS REV24RF

1) yes
2) yes

prefer 2 over 1

 

[infrequentuser]

Thanks for the confirmation. It is good to know thay I have got it right.

Any special reason for prefering the Siemens REV24RF over the Honeywell CM927 ?

 

[gerardo]

I have just fitted the Honeywell in replacement of a Salus RT500RF and belive it to be a great device.

I am unaware of the Siemens but he Honeywell was physically easier to wire and has some good options such as being able to set the temp to for when you wish it to be warm and it will calculate when it needs to come on.

The Honeywell can also be set in a "Sunday" mode should you be off for a while (winter hols etc). It has many more settings, however I cannot comment on the Siemens.

Our receiver is in the hallway and the transmitter in the cooler extension; works a treat and very stable temperature with the use of TRV's in the other rooms.

 

[seco services]

Any special reason for prefering the Siemens REV24RF over the Honeywell CM927 ?

find you get a better signal with the siemens.

 

[itlc198]

I'm looking to replace my honeywell DT90E with a REV24RF for the same reason as the OP.

I also have a 3-core-earth which is wired as follows:

Red to 'A'
Yellow to 'B'
Blue and Earth 'isolated' in connector block.

Having little or no electrical knowledge / experience I have a few questions:

1) Is there anything I need to check with respect to the existing wiring to ensure the REV24RF will work?

2) Does 'Earth → Back Box only' mean isolate in a connector block(as per current setup) or should this be wired into the back box somehow?

3) What does 'Short piece of Red wire connecting Terminals L (Phase) and Lx (Phase)' actually do? From the user guide it suggests that the L (Phase AC 230V) is connecting the Lx (AC 24...250V) but I'm not sure what this really means.

I realise these may be very basic questions but any assistance would be gratefully appreciated - I'm very keen to learn.

Many thanks in advance.