Heating an empty home to prevent frozen pipes, damage, etc - timer settings?

What_time_is_it

Hi. We are currently selling my mother-in-law's house and it is mostly empty with nobody visiting during the week. We want to make sure that the cold weather doesn't damage the house at all, but we don't want to leave the heating on all the time! It's an old house with minimal insulation, a very law EPG rating, single glazing, and a really old boiler with a basic timer and thermostat. The boiler allows us to choose a setting of 1-6 for heat, and we set 2 time periods where the heating is on.

We have it on for 2x 2 hours - once in the evening about 8pm - 10pm and then again in the morning about 5am-7am. Is that enough? Should we have it on more this week with temperatures so low? Should I be worried about damage to the pipes, etc?

What would you do?

Gerry1

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

What_time_is_it

Gerry1 said:

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

Thanks. The stopcock is jammed so we can't do that. And we can't set a temperature either. The boiler can just be on or off and set on a dial from 1-6 for temperature with 6 being the hottest. It can be on all of the time (which is about £60+ a day) or set to come on during two specified time periods. Perhaps we need it on more that two blocks of two hours?

Hoenir

There's no thermostat in the property? 

Swipe

You'd be very unlucky to get frozen pipes with your current schedule. As long as the house is getting to around 10C when it's on and there's water flowing through the pipes you'll be fine. Although it is going to be very cold on Wednesday night, for pipes to freeze it really needs a prolonged cold spell with sub zero day time temps and no heating for a few days.

What_time_is_it

Hoenir said:

There's no thermostat in the property? 

Nope. Really old one-pipe heating system that heats up each radiator in turn and a boiler from the 1980s with basic settings as described. The only way to choose a temperature is the 1-6 dial!

What_time_is_it

Swipe said:

You've be very unlucky to get frozen pipes with your current schedule. As long as the house is getting to around 10C when it's on and there's water flowing through the pipes you'll be fine. Although it is going to be very cold on Wednesday night, for pipes to freeze it really needs a prolonged cold spell with sub zero day time temps and no heating for a few days.

Thanks. There will be heating on at some point each night as described. The indoor temperature of the house will certainly be below 10C though. Maybe about 5. 

ArbitraryRandom

What_time_is_it said:

Gerry1 said:

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

Thanks. The stopcock is jammed so we can't do that. And we can't set a temperature either. The boiler can just be on or off and set on a dial from 1-6 for temperature with 6 being the hottest. It can be on all of the time (which is about £60+ a day) or set to come on during two specified time periods. Perhaps we need it on more that two blocks of two hours?

I would strongly suggest you get a plumber out to sort that... 

I would guess '1' is the 'frost free' setting @ around 10 degrees.  

Forecast suggests it'll be very cold this week followed by a warmer spell, so I agree with Gerry that I'd leave it at 1 or two at least this week, see how many units it's using, and maybe pick up a cheap min/max wifi thermometer to leave in the kitchen/bathroom (the two areas where you're most likely to have problems with pipes) to check the temp via your phone remotely. 

Gerry is also right that you need to have a look at the building/contents insurance and check if you need to notify your insurers the property will be vacant etc. 

What_time_is_it

ArbitraryRandom said:

What_time_is_it said:

Gerry1 said:

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

Thanks. The stopcock is jammed so we can't do that. And we can't set a temperature either. The boiler can just be on or off and set on a dial from 1-6 for temperature with 6 being the hottest. It can be on all of the time (which is about £60+ a day) or set to come on during two specified time periods. Perhaps we need it on more that two blocks of two hours?

I would strongly suggest you get a plumber out to sort that... 

I would guess '1' is the 'frost free' setting @ around 10 degrees.  

Forecast suggests it'll be very cold this week followed by a warmer spell, so I agree with Gerry that I'd leave it at 1 or two at least this week, see how many units it's using, and maybe pick up a cheap min/max wifi thermometer to leave in the kitchen/bathroom (the two areas where you're most likely to have problems with pipes) to check the temp via your phone remotely. 

Gerry is also right that you need to have a look at the building/contents insurance and check if you need to notify your insurers the property will be vacant etc. 

Thanks. We've got vacant property insurance.
Great tip regarding wifi thermometers.

Sounds like we need to have the heating left on for longer than we currently have it anyway. The problem is that we won't be there until around midnight on Wednesday so we might have to cross our fingers for the next few days. Bit worried to be honest.

Swipe

What_time_is_it said:

Sounds like we need to have the heating left on for longer than we currently have it anyway. The problem is that we won't be there until around midnight on Wednesday so we might have to cross our fingers for the next few days. Bit worried to be honest.

As long as you get there by midnight Wednesday I think you'll be fine. Wednesday night / Thursday morning will be the low point of the week. My bathroom often gets down to below 5C during cold spells and I've never had in internal pipe freeze, just the external garden outside tap pipe that goes through the bathroom wall and then it only freezes on the outside even when it's insulated. I now isolate it via the internal valve and open the tap. And even when the outside tap did freeze on multiple occasions, it didn't burst the pipe.

Gerry1

What_time_is_it said:

Gerry1 said:

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

Thanks. The stopcock is jammed so we can't do that.

Turn it off at the stopcock in the street.

What_time_is_it said:

Gerry1 said:

Leave it on the whole time with the thermostat set to 10⁰-12⁰C or whatever the insurance company requires.  Turn the water off at the stopcock.

Saving a few pounds would be a false economy if the pipes burst and flood the place.

It can be on all of the time (which is about £60+ a day)

Not unless you have guardsmen in bearskin hats outside.  Even a 28kW boiler going full pelt 24h would only cost around £47 per day.

Err on the side of caution, open the loft hatch as well.  A flood doesn't bear thinking about, especially after exchange of contracts.