Programmer for Worcester Greenstar 30CDi Classic System Boiler

3 Jul 2011
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United Kingdom
Hi everyone

I have bought a Worcester Greenstar 30CDi Classic System Boiler, but have not yet bought the programmer.

In my last house we had a Honeywell CMT927 and it worked very well indeed, and was so easy to understand. Do you know whether this unit will work with the WB 30CDi?

I see it for sale on Amazon, is this all I need? Will my boiler connect directly in to the Receiver Unit? My plumber will do all the connections, but for now he is just asking me to choose a programmer.

Thanks very much for the help and advice.
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As you have a "System Boiler" that indicates that you have a hot water cylinder, which will also required timed control.

The Honeywell CMT927 is just a programmable thermostat providing control for central heating only. It is primarily used with combi boilers and does not have the ability to control a hot water system. So if you wanted to use it, you would also need an additional timeswitch / programmer to provide control of the hot water system.

The Honeywell thermostat will only work work with a Honeywell receiver, which would be hardwired to operate a motorised valve controlling the central heating. It would not be wired to the boiler.
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Thanks for the reply.

As well as the WB system boiler, I have an "Telford Tempest Stainless Steel Indirect 300L Unvented Cylinder" for hot water.

So I need a programmer that does both HW and CH? Can someone recommend a model please, I like Honeywell and Danfoss (as they are easy to understand). And the programmer needs to be wireless please as both the boiler and the HWC will be in the loft.

Some more info: the CH will be wet underfloor heating for ground floor, and radiators for first floor.

Thanks for the help.
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When you use the term "will be" that suggests that this is a new installation & not just a boiler replacement. If so, you should really discuss it with the heating engineer designing the installation as there are various control options that will depend upon the installed system. For example, if this is a new installation, it should have separately controlled heating zones for the living and sleeping areas [Building regulations requirement] each with their own time & temperature control. So, a traditional programmer just providing on/off times for the entire heating system won't be suitable. In this case, you could use a programmable thermostat for each heating zone, and a separate programmer for the hot water.

It would also be good to include whoever will be undertaking the electrical installation in the discussiontoo, because there will be additional wiring associated with the UFH manifold and its accessories and the installer may have certain preferences, or products they use.

Honeywell and Danfoss do make good products, you may also want to consider something such as Honeywell Evohome for example.
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Thanks very much for the advice. The house was built in the 1970's and I am refurbing it. I do need to catch up with the plumber who is a bit busy at the moment.

He has already installed the boiler and HWC (both not yet commissioned as waiting for incoming water main (upsized) to be re-connected by the water company).

I will have a separate thermostat for the upstairs (bedrooms heated by radiators). And I will have a seperate thermostat for the downstairs (living areas heated by wet UFH).

For the upstairs, I like the Honeywell T6R-HW Wireless Thermostat (with hot water control) as it looks simple to use. I am hoping it will be suitable for use with the WB boiler.

For the downstairs, I would also like a wireless unit. Any suggestions?

Could I perhaps have another Honeywell T6R somehow configured for UFH? It would be great if all members of the house only had one thermostat/programmer unit to learn how to use!

Thanks again.

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