Boiler control with wireless thermostat

[redbarnman]

My son needs a new boiler and has gone for a Worcester Bosch 18Ri RSF. We thought of using a Honeywell CM927 wireless controler for CH but how do you control hot water - does that need a separate clock/thermostat. It will be an S plan arrangement most likely

 

[BLOD]

You will still need a 2 channel programmer for ch & hw. The cm927 is basically a fancy room thermostat that lets you set timings & temperatures for the heating.

hope this helps

 

[doitmyself]

You will still need a 2 channel programmer for ch & hw. The cm927 is basically a fancy room thermostat that lets you set timings & temperatures for the heating.

The CM927 is a programmable stat, so you only need a single channel timer for the HW - something like the Honeywell ST9100A or ST9100C

 

[SafeGasInstall]

HONEYWELL ST9400S PROGRAMMER 24HR 2 CHANNEL SI HEATING Central Heating Controls HEATING

 

[Billy Bob Bob]

HONEYWELL ST9400S PROGRAMMER 24HR 2 CHANNEL SI HEATING Central Heating Controls HEATING

thats the one you will need

 

[doitmyself]

thats the one you will need

No, it is not!

You do NOT need a two channel programmer if you are using a programmable thermostat.

 

[SafeGasInstall]

we are on about using control panel for hot/cold ....rather then making things complicate doitmyself

 

[bert large]

Easier to wire it as a standard Y or S plan, leave the heating channel "on" & then control the heating with the 927. Thats what I would do anyway.

 

[bert large]

Sorry, should have said "Y or S plan with a 2 channel timer"

 

[doitmyself]

we are on about using control panel for hot/cold ....rather then making things complicate doitmyself

But having the heating controlled from two places does make things complicated. After all, if you have a two channel programmer, you will just set it so the CH is permanently on, which means you might as well do away with that channel completely.

 

[dumbrill]

I agree a single channel timer is all that is required and this would control the HW. The CH would be controlled entirely by the CM927. Introducing another timer into the CH control will cause confusion. The only reason I could think of for using a two channel timer would be because a single channel timer might be more expensive as it is more unusual. Also a two channel timer adds some redundancy in case one channel fails. Then the other can be used. However to answer the original question all that is required is: a CM927 for CH and a ST9100C for HW. This combination would provide complete control across all 7 days of the week.

 

[redbarnman]

Thanks to all for responses, I think we have a way forwards - and after reading other posts on the forum it looks as though he will now go with Vaillant for the boiler as there seems to be a concensus that they are better build quality. All he has to do now is find a reasonably priced plumber in West London.