Why does my smart meter show I am using gas throughout the night?

[Wigeon]

Recently moved house and got a smart meter for the first time. It’s showing that almost every night we are using a few kWh every hour of the night, and weirdly 9kWh at 1.30am on this date. It’s a 20 year old boiler, set to come on in the morning and evening for central heating and hot water. There’s a hot water tank in the loft.

Any clue why there appears to be gas use in the night?

@Clem89 - thank you for taking the time to post advice! The hot water and central heating are both set for limited periods in the morning and evening, but the spikes are in the middle of the night, and inconsistent.

I’ve just been sitting in the kitchen near the boiler, and it’s come on twice in 15 mins, for about a minute each time, even though the central heating is turned off at the control panel, the hot water is set to come on much later on today, the thermostat in the hallway is turned right down to 10 degrees just to be sure, and it’s definitely above 5 or 10 degrees inside, so surely it’s not a frost setting thing. I think it’s probably around 16 degrees in the kitchen/ hallway (it’s 13 degrees outside, so not a cold day for January).

Still quite confused. Will see what the heating /plumbing guy says on Monday!

Not a problem. You have done the right thing by having a heating engineer come round to have a look. I'll be very interested to hear the outcome.

Inconsistent spikes are suggestive that your boiler is topping up the temperature of your stored water. At least you can eliminate the guess work once the engineer visits.

Unfortunately I am not a heating engineer, but I have plenty of experience and information to hand.

I recommend sealing up any drafts or gaps where heat may escape but not the designated ventilation areas for your homes brickwork. When you heat your home, heat travels to cold zones so make sure all heaters/radiators are on. Start your thermostat at 18 degrees. Wait half an hour if you need more heat, adjust the temperature by 1 degree wait another half and hour. Rinse and repeat until you find your goldilocks zone. Allow the thermostat to do its job and try to avoid switching your heating on and off as your boiler uses the most energy when heating up from being cold.

Avoid leaving your doors open. Close any door covering up any drafts this is the most efficient way to heat your home. Once your home is heated to your desired temperature do not switch off your gas/heating/boiler. I live in a 3 storey home, I never switch off the heating, i just allow the thermostat to top up the heat as and when the temp drops. I have drafts everywhere which are unsaleable. I use on average around £8 pounds per day on the colder windier days. This has been since the beginning of December.

Hope this helps you going forwards.

Like another poster, ours has a clearly identified switch on the front of the boiler to turn off the pre-heat. Hope by now you’ve managed to find the boiler manual online to work out how turn off on yours

Hmm… I guess mine is so d it only has 2 disks for the temperature of the hot water and radiator water, a reset button and an on/off switch to turn the boiler off 🤦🏻‍♀️

I will look for the button when I get a new boiler…

Update now the plumber /heating guy has been - there is no pilot light, so it’s definitely not that. We have also had a leak from a valve and pump attached to the hot water cylinder, and it’s been dripping onto another value on the boiler which controls when the boiler comes on and off, so he thinks it’s possible that water has been getting into that valve, causing it to malfunction and causing the boiler to randomly come on. He’s coming back on Wednesday to replace those bits and thinks that will probably fix it.

In the meantime, he’s turned off the gas right by the meter (and shown me how to turn it back on!), so that I can do an experiment and see if the smart meter shows any gas usage during the day today, and if it does, then there might also be a problem with the smart meter.

Thanks again for all the comments!

That will be useful. do report back when you have done that experiment.

We have a simialr system but no thermostat at all and I have the hot water on once in morning and once at night which is eough for all of us. We have a weird system with the radiators in the bathrooms acting as towel heaters however so they go on when the hot water is on even if the heating is off (unless in summer we turn them off at the individual radiators themselves)

Update! So, turning off the gas at the mains meant that the app showed no gas usage at all during the time it was turned off, as you’d expect, which proved it wasn’t a fault with the smart meter.

Plumber/heating guy then yesterday replaced a pump, valves and another pump on the hot water cylinder, and horray! Again, no usage showing on the app in the middle of the night. So it does look like the leak from a valve which was dripping into a pump was causing it to malfunction and put the boiler on intermittently, even when the heating controls were off.

Really glad it seems to be sorted and we won’t be paying for gas that we really don’t want to be using!

That is kind of weird.

AFAIK all that operating a valve would do would enable the water flow to the relevant components of the system.

The boiler demand would be fired up by the thermostat/thermal controller and in my system anyway is completely independent of the valves that switch the hot water cylinder in circuit or not.

Anyway, mine is not to reason why. Maybe you have a different system - whatever works for you.

Congratulations either way, resolved.