At what outside temperature could the pipes freeze? Can we get away with this…

If the boiler or controller is off, I'd doubt that it's going to switch on to respond to a temperature drop.

We have a Hive which I expect works a similar way to a Nest. There's an app that you download and use this to set the heating timer so it changes the temperature according to your lifestyle, budget, preferences etc.

Then you can also switch to frost protection when you're away, which won't heat an unoccupied house, but come on if the temperature goes below about 5 C, but unless the weather changes significantly I don't think there's a risk of frozen pipes.

So look at the app, loads easier and probably cheaper than manually switching the heating on and off.

Unless money is very tight I'd just leave it on.

“At what temperature could the pipes freeze..” well I’m going to go out on a limb and say any temp below 0degC.

Can't see anything of real concern for midlands weather over the next week or so but if you are concerned, just leave it on low.

Suffered badly with burst pipes when I bought my first house back in 85.
It was a doerupper and I didn't live there for several months, instead my Ddad and myself visited every day or so to do some work (no central heating, just gas fire & heaters). He advised we always turned the water off when we left as it was a horrible winter with the snow sitting on the ground for weeks🥶. One day we turned the water on and as the house warmed up we discovered we had seven burst pipes so the day was spent fixing them (luckily my Ddad was old school so could actually deal with it).
From that day, as well as turning off the water, we also drained down to prevent it happening again.
1930's semi with no cavity and metal framed single glazed windows, took some heating I can tell you!

I've never had a pipe freeze (not to say it won't happen, probably just jinxed myself 🙄)
When I had central heating installed in my old house, the installer put a copper pipe running up the outside of the house.
Apparently, it should have been inside.
That never froze either.
It went through the Beast from the East with no problems.
I'm in North Yorkshire.
However, if you're worried, leave your heating on low so it comes on it the temperature drops

If you have a water tank in the loft that no one can get to, it will need a clean. That's more of a concern than pipes freezing in 2c weather! X

Couple of other things to consider:

• heating helps keep dampness at bay
• things will take a while you warn back up after you get home.

I'd be tempted to turn thr heating down, not off.

Usually pipes freeze when you have a long session of well below freezing for a few nights and not above about 4 in the day, forecast is not that for the next week or so. Our condensate pipe froze in 2023 when we had that spell of very cold for about a week, I think it went down to about -10 but that pipe can freeze even if you have your heating on for some hours of the day and off at night.

If you have a Nest, just programme it on the frost protection setting or holiday mode, or set the temperature to something between 5 and 15 C and the heating won't come on unless the temperature drops hugely from how it is now as its really mild for December so it won't come on but also no risk of pipes freezing. No need to turn the boiler off.

My dad sold central heating in the 1970s/1980s his advice has always been to have the heating come on in the small hours for an hour or so.

That's because it is usually the coldest at 2am or 3am.

We have an empty probate house. We only put the heating on if it’s going to be really cold, otherwise just a couple of hours a week. We are in a cold, damp, exposed corner of the Pennines. It will be fine.

I'm also in the Midlands, a number of our water pipes are external. It causes endless problems but freezing pipes isn't one of them. Unless we start getting temperatures around -7°c, I don't worry and even if the temperature gets that low, I put one of those insulated pool noodle things over them.

You'll be absolutely fine

It has to be sustained low temperatures, it's going to be around about 8 in the day and not less than 0 at night.

Our frost protection thing on the thermostat is 5 degrees. Lowest I've ever seen the house get is 8 degrees, and that's when it was -8 outside

Even if the pipes are in the loft, if the temperature isn’t below zero, they won’t freeze. What you need to do is check the weather forecast carefully.

It's going to get pretty cold over New Year - can't you just leave it on 7 or something? That's our system default if it's not actually doing anything, as such.

Some water systems have a cold water tank up in the loft. Lofts usually have their floor insulated, so are colder than the house - although it you do have a tank in the loft you should run the insulation over it rather than under it. Hence a PP's comment that your pipes are more in danger if there are some i the loft.

Technically water starts to freeze at 4°C and finishes freezing at 0°C, which is why boiler frost protection starts at 5°C normally and fridges are typically set around 4°C so they don't ice inside.

But even when it below freezing overnight, even without heating and windows open I only get down to about 8 or 9 inside. So even in the loft if the pipes are lagged it will take a long time in below freezing conditions to have a problem.

It's relatively mild for the time of year.

If you're that worried, turn the thermostat down to, say, 15 deg. so that the heating will come of if it gets really cold. It's unlikely to kick in at all.