Broken boiler - do I need to drain pipes in cold weather?

[slewts]

We are currently working abroad and are flying back to the U.K. on 11th December. Our ancient boiler failed in October and we are due to have it replaced on 12th December. So far I’ve been praying for mild weather but next week temperatures are dipping, and it’s forecast to be freezing / -1 degrees next weekend. We are in North Wales by the coast.

Do we need to drain the system to reduce the risk of pipes bursting? Will the plumber need to drain the system anyway to replace the boiler? My husbands brother used to be a plumber so we can ask him to do this for us, but husband thinks I’m worrying over nothing.

The house is an Edwardian semi with full cellars and fairly poor insulation. Most pipe work and all radiators have been replaced in the last two years, but don’t think any pipes are insulated.

I'd drain it down, to be on the safe side.
I had a frozen pipe burst on me, but that was in 2010 when we had a full week of heavy snow without a working boiler (we had ran out of oil, and couldn't get an oil delivery because of the snow). I don't think a few frosty mornings will cause a pipe to burst, I think it has to be consistently freezing over a number of days, but from my experience i'd definitely be wary and drain it down to be on the safe side. The plumber would have to drain the system down to replace the boiler anyway.

Yes, get the system drained and also turn off the water at the stopcock. Also use the opportunity to have trvs fitted on the radiators.
Can your BiL stick some system cleaner in a few days before draining it? You’ll be amazed at the difference in performance a clean system will make to a new boiler.