Modulating stats?? With worcester CDI combi

[r896neo]

I am having a WB greenstar CDI combi fitted on a new system.

Because the boiler is fully modulating is a normal wirless programmable stat such as a Honeywell CMT921 going to make the most of this or should i go for the WB FR110?

In essence i want to know if the stat has a part to play in the modulating or is this all done by the boiler?

Many thanks

 

[ALEC1]

go for the Wocester modulating stat..

all boilers modulate the heat input by lowering the gas rate, but only modulating thermostats modulate the flow temperature, enhancong boiler efficnecy..

Honeywell products do not do this...

 

[r896neo]

thanks so much for the reply.

Would there be any chance of a brief description of why modulating the flow improves efficiency?

I am meeting the plumber in the morning to choose one and unfortunately even though he is a WB installer has never fitted a modulating stat or Weather compensator and doesn;t seem to know anything about them.

Really appreciate it, especially on a friday night.

 

[ALEC1]

because modulating stats run to as low a temperature as possible to maintain the room temperature...they make the boiler work around room temperature... so the bigger the deviance from the set point of the room sensor the hotter the radiators...and vv..

this ensures the boiler is as efficient as possible given the conditions.

it also removes "overshoot" as the rads lower the temperature as the room temp approaches set point.

weather comp is for bigger systems...where measuring room temp in one place is not such a good idea...

 

[r896neo]

thanks again.