What system is this? Combi with extra thermostats?

[bilabonic]

Hi all

My parents have just moved into a bungalow and the gas combi boiler is in the garage.

Any idea why it has an extra stat in there linked to the RF controller and another valve/stat on one of the pipes?

I was thinking it’s done form of frost protection/low setting but boilers have this built in anyway?

There is a wireless stat inside that controls heating and works fine.

Anyone?

 

[dpgas]

Yup its a frost stat and a pipe stat.

They may be from a previous older boiler and have been left wired in when replacing with the newer boiler.

 

[bilabonic]

That makes sense.
Must be leftover from an older system then?

What should the frost stat be set at as I presume this will override the built in frost protection of the boiler.
Thanks

 

[flameport]

but boilers have this built in anyway?

They do, but that only protects the boiler as it has no way of sensing the air temperature outside of the casing.

 

[stem]

There has just been a thread all about a problem with this type of set up that was wrongly installed. Yours likely will have been installed correctly, but the thread will give you an idea of how it works and what to set it to. You can read it here.