I have a Baxi 105e boiler and cannot find out whether it has a froststat built in.  Given that I have an efficient roomstat do I need a froststat as well? And if so do I need a roomstat also?

The house will be left unoccupied for long periods.

I assume these are wired in parallel with the roomstat?

Thanks in advance

John D

The external frost stat will bypass the timeclock as well as the standard room stat.  Whenever the temperature drops below (say 3º), the heating will come one, regardless of the time of day.

A comprehensive system would also have a pipe stat on the boiler return pipework, wired in series with the frost stat.  That way, as soon as warm water starts to return the boiler, the boiler is turned off again, so it just keeps the pipework warm.

You want to heat your house though don't you?  So you would be better of with a thermostat set low.