Wireless Room Thermostat & Existing Potterton EP6002

[triopowell]

Hi,

Have a Halstead ACE Boiler at the moment, already added a Potterton EP6002 to it a few years back, but at present don't have a room thermostat, just TRV's around the house.

Question is can I add a Wireless Room Stat to the system, will the Wireless stat coexist with the existing programmer? I can see from the boiler wiring diagrams that there are two contacts available for the stat, but do I need to incorporate the programmer into the wiring? Looking at getting something like the Honeywell CM927, or whatever the current model number is, unless there are any recommendations.

Thanks a lot.

 

[D_Hailsham]

Question is can I add a Wireless Room Stat to the system, will the Wireless stat coexist with the existing programmer?

Yes to both questions.

do I need to incorporate the programmer into the wiring? Looking at getting something like the Honeywell CM927

The CM927 is a programmable heating thermostat, so it would take over from the EP6002 for controlling the Heating times; but the EP6002 would continue to control the Hot Water times.

You will need a four-wire (plus earth - unused) cable for the CM927 receiver.

The CM927 is very good.

If you have TRVs on all rads this will conflict with the Room thermostat. The TRV in the area where you put the stat should really be replaced by a standard valve; but you can get away with setting the TRV to Max.

 

[triopowell]

Thats great information, I don't need to worry about the hot water as its a Combi therefore I don't have a hot water tank.

So will the EP6002 end up being completely redundant in my case, ie not needed for hot water?

Thanks for the information so far.

 

[D_Hailsham]

So will the EP6002 end up being completely redundant in my case?

In theory it should be redundant. However the EP6002 has four additional terminals labelled A-D. if any of these have been used you will need a separate junction box with the correct number of terminals. Take the EP6002 of the backplate and see what is going on.

If terminals A-D are not used then it's a simple job to wire the CM927 receiver in place of the EP6002:

EP6002 -- CM927
L ------------- L
N ------------- N
4 ------------- B
--------------- A link to L (either)

As you have a combi, terminals 1-3 of the EP6002 should not have any wires in them.