Is a frost stat required in this case?

We have recently had a heat only gas boiler fitted to replace an existing unit due to corrosion destroying the outer casing. The plumber says we will need to have a frost stat fitted by an electrician as the boiler is in a garage. The garage is integral and has a bedroom above it with an insulated loft above. The garage is therefore unlikely to drop below freezing. Are there any specific regulations regarding when a frost stat is required? Fitting one in this installation will be a pain as the boiler has no permanent supply and is switched on by a controller at the other end of the house. A frost stat would need to be wired back to the controller so that it operates both the boiler and the circulating pump.

I'm not sure as to the frost stat, but for the purpose of water services a garage would be usually be classed as a cold space unless proved otherwise with adequate insulation (garage doors usually rule out "adequate").

With the exception of when the boiler is operating, I imagine your garage would be totally unheated...

Check the boiler manual. Many boilers incorporate a built in frost thermostat that lights the boiler should the temperature get to near zero.

You might also think about putting an enclosure or cupboard around the boiler. That should stop it cycling on and off frequently without trying to keep the whole garage warm.

A cupboard would have no effect on the boiler cycling at all, modern boilers do not heat up the rooms they are within. a pipe stat combined with a frost stat powered from within the garage would suffice.