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?

the boiler will have a pilot light that is always on, but it should only be burning a tiny trickle of gas. if the boiler is malfunctioning this tiny trickle might be more than expected.

Do you have any thermostats which switch on below a certain level?

Have you definitely not got the heating on overnight?

If the temperature drops below a certain temperature, it will come on.

That's the most obvious explanation

Could it be when they register the standing charge?

Well we think we’ve set the controls to only be on for set periods, and not on at all for the rest of the time. The thermostat is fixed to the wall in the hallway, and we also turn that down to 10 degrees (the lowest mark on the dial), and only turn it up (during the hours we think we’ve set the heating to be on) if we actually do want the heating on.

The Ovo app reckons we are using loads more gas & electric than similar households, even though we all go around in jumpers etc and the children complain it’s cold!

I figure not, because the app is showing usage on kWh, which wouldn’t be the standing charge?

Can you hear the boiler firing up in the night? Is it a combi boiler and does it have some form of pre-heat for the hot water? Ours does and it makes the boiler come on at random times. We turned that functionality off, made no noticeable difference to the hot water but the boiler only comes on now when we turn on the hot water tap or the heating comes on.

It’s not a combi, it’s the sort which heats up a hot water tank for fixed periods that you set, and once it’s heated up the water that’s all you’ve got, until the next time. But I do think I can hear the buzz of the boiler (or maybe the tanks in the loft?) when I’m in bed at night - it’s a bit hard to know where it’s coming from given we’ve only been in the house a month. Which is confusing because I thought we had set it to only operate at hours when we are awake.

Is it keeping the hot water hot all the time? We do this because it's more efficient than letting the rank go cold and reheating from cold. Our heating also runs off the tank.

I had this when one of my zone valves was stuck on so it was creating demand when the boiler was off. Switched the boiler off for 24hrs to work it out! Cost about £80 to replace, might be worth checking something like that, especially if they're old.
The clue was the heating pump (mines in my airing cupboard but it could be near the hot water tank) was running constantly even when the boiler/gas was off at the mains and all thermostats off.

@jevoudrais I was under the impression that as long as your tank is sufficiently insulated, in theory you can heat up the water and then it stays hot for a period, by which time you’ve used it up, and then next time it turns on, it heats up the next lot of water? But this is all new to us, we had a combi in the last house.

I think it's probably your pilot light. Unless of course, you've got a leak somewhere! Might be worth getting it checked.

I have a hot water cylinder too and only heat the water for 1 hour per day and that seems to be sufficient for our needs.

Has the boiler been serviced recently?

When I woke this morning , and everything was off , been looking after my house for 50 years , know how to economies, my gas was 1.04 , and electric 1.48 , why theses charges r so high is ridiculous, that how theses big companys r making so much money , charging us just to have the gas and electric in our homes, thatsxwithour the standing charge , something needs to be done , my own house which is empty for xmas and new year has incurred gas and electric with only the fridge freezer running , daylight robbery

@Wigeon it depends on your set up.

My tank will drop temp significantly over a few hours, and this means that if I want the heating on, the tank has to be made hot again for the heating to work. I think it's less common for the heating to work in this way but it clearly is still like that for some, as it is for us.

@dementedpixie - have just changed the boiler to only turn on for an hour a day for hot water - will see how we get on. How many people in your household having showers/baths etc? Boiler was serviced in November by the previous owners (they had one of those plans with British Gas).

@Wigeon Our showers are electric and appliances are cold fill so we don't need a lot of hot water heated by the boiler. We tend to use the shower rather than having a bath so you'd need to tailor your timings to your own needs.

Maybe you should add more insulation to your hot water cylinder to prevent the temperature dropping so much. My hot water is on for hour per day

For 1 hour that should say

Op it's probably the anti freeze setting kicking in, I posted about this a couple of weeks ago snd done some digging in google when I got answers.
When the temperature goes down the boiler kicks in and pumps water through the system, it stops the central heating system freezing and breaking down.
They're normally set from between 5/10 c.
When we had those really cold days mine was on and off that many times through the night it cos me just under £4 in two days. It's not going on now though since the temps went up a bit.

Hm, I wonder if the antifreeze is set to 10 degrees - the thermostat is in the hallway but the other end from a draughty front door (that we have just ordered curtains for!), so I guess it’s possible the hallway gets down to 10 degrees at night, although it doesn’t feel that cold when we go down in the morning (sometimes quite early, eg 6.30am). I think we need the plumber round to help work out what’s going on…

I doubt it's gas tbh as it's registering £9.00 odd but only using about 17kwh on that useage and that's about 4 times the price of gas is it showing your readings as duel fuel readying but even so it's a lot still what's it read for 24 hours approx total?

Two things, depending on how your boiler works.

Either pilot light is using gas or
Standing charges as stated above as included.

I have had smes2 meter installed recently and it includes standing charges after midnight and also shows my pilot light usage.

Does your boiler have electronic ignition or does it have the old fashioned pilot light system?

If it has a pilot light then that could explain some of this because they are constantly lit.