Excessive Gas Consumption - Not sure what to try next!

[Harry Bloomfield]

Does your in home display for the meters, show instantaneous gas consumption levels? If it does, one thing you could try, when the boiler fires up, with the house from cold - is the Kw it is burning. It should show close to 30Kw, if the boilers maximum rating is 30Kw.

 

[Mister Banks]

Thanks so much, this at least lets me know it's not wildly out for the property.

I will have to look at getting cavity wall insulation done soon and other measures.

I live in a large 4 bed house built in 1996 in the south of England and our gas usage for December was just over 1900kWh so I think you have an issue at 5000kWh usage. From what you have said there is no gas usage when the boiler is off so there must be an issue with the boiler setup.

 

[mjr_havoc]

I should mention that my boiler is old so not as efficient as yours.

Agreed, but that's the other thing that puzzles me... My tado system which controls the boiler for heating and hot water shows considerably less gas usage as compared to the octopus smart meter readings.

So the attached is a screenshot from my Tado system showing usage for Jan so far. Actual consumption of 1,353 kWh for 01-20 Jan.

The actual meter readings were 601m³ on 01/01/2025 and 993m³ today. This is a usage of 392m³ which is roughly 4,454 kWh (using one of the many online converters).

Now how can these two figures be so wildly out? Even assuming that the Tado figures are rough and ready, and the conversion from m³ to kWh varies slightly from one calculator to the next, how can the actual gas usage be 3.3 times the estimate from the Tado system?

Note: the Tado system was only installed recently so I don't have data to cover the bill period mentioned in my original post.

 

[Mister Banks]

Agreed, but that's the other thing that puzzles me... My tado system which controls the boiler for heating and hot water shows considerably less gas usage as compared to the octopus smart meter readings.

So the attached is a screenshot from my Tado system showing usage for Jan so far. Actual consumption of 1,353 kWh for 01-20 Jan.

The actual meter readings were 601m³ on 01/01/2025 and 993m³ today. This is a usage of 392m³ which is roughly 4,454 kWh (using one of the many online converters).

Now how can these two figures be so wildly out? Even assuming that the Tado figures are rough and ready, and the conversion from m³ to kWh varies slightly from one calculator to the next, how can the actual gas usage be 3.3 times the estimate from the Tado system?

Note: the Tado system was only installed recently so I don't have data to cover the bill period mentioned in my original post.

Where does Tado get its information from?

 

[Murdochcat]

Maybe not in Surrey! North of England has been very cold!

Probably not but giving an indication of your location might help

 

[mjr_havoc]

Does your in home display for the meters, show instantaneous gas consumption levels? If it does, one thing you could try, when the boiler fires up, with the house from cold - is the Kw it is burning. It should show close to 30Kw, if the boilers maximum rating is 30Kw.

Here is a screenshot from my Octopus app. I turned off the boiler at about 10am for a couple of hours so you can see zero usage until I turned it back on. The boiler is installed in the garage so was cold before I turned it back on. However the gas usage only peaked to about 10 kWh as you can see from the picture.

 

[MNW67]

.

 

[fourtytwo]

Agreed, but that's the other thing that puzzles me... My tado system which controls the boiler for heating and hot water shows considerably less gas usage as compared to the octopus smart meter readings.

So the attached is a screenshot from my Tado system showing usage for Jan so far. Actual consumption of 1,353 kWh for 01-20 Jan.

The actual meter readings were 601m³ on 01/01/2025 and 993m³ today. This is a usage of 392m³ which is roughly 4,454 kWh (using one of the many online converters).

Now how can these two figures be so wildly out? Even assuming that the Tado figures are rough and ready, and the conversion from m³ to kWh varies slightly from one calculator to the next, how can the actual gas usage be 3.3 times the estimate from the Tado system?

Note: the Tado system was only installed recently so I don't have data to cover the bill period mentioned in my original post.

Forget Tado it is not measuring anything but trying to estimate it, quote from there own website
"We estimate (heating) energy consumption based on historic tado° heating data. To make an accurate estimate, we need the energy consumption data from at least two energy bills. Just the meter readings, no personal data. We need this data to calibrate our abstract heating data to your individual heating system."
Why people waste money on useless gadgets defeats me!

 

[mjr_havoc]

Where does Tado get its information from?

A very good question! After fiddling around in the app for a bit it looks like it's a combination of estimates based on how many times it has to call for heat/hot water and meter readings.

See the attached screenshot from the app which explains this. I have added all the meter readings fir the new meter but the actual usage hasn't changed at all which seems to suggest that the actual usage is from how many times it called the boiler, but the forward-looking forecast must use the meter reading data...

 

[fourtytwo]

Here is a screenshot from my Octopus app. I turned off the boiler at about 10am for a couple of hours so you can see zero usage until I turned it back on. The boiler is installed in the garage so was cold before I turned it back on. However the gas usage only peaked to about 10 kWh as you can see from the picture.

That is NOT peak consumption, it is consumption averaged over 1/2 hourly intervals.
As you seem to be running your heating system all day I am not surprised at your consumption.
Are you using radiator thermostats on all radiators or just a room stat ?
Does your frost stat run all the radiators ?

 

[mjr_havoc]

That is NOT peak consumption, it is consumption averaged over 1/2 hourly intervals.
As you seem to be running your heating system all day I am not surprised at your consumption.
Are you using radiator thermostats on all radiators or just a room stat ?

I have Tado trvs on all radiators except the towel rails in the bathrooms (which have traditional trvs).

Tomorrow, when there is noone at home I will turn off the boiler and measure the actual usage via meter reads when turned on from cold.

 

[Mister Banks]

A very good question! After fiddling around in the app for a bit it looks like it's a combination of estimates based on how many times it has to call for heat/hot water and meter readings.

See the attached screenshot from the app which explains this. I have added all the meter readings fir the new meter but the actual usage hasn't changed at all which seems to suggest that the actual usage is from how many times it called the boiler, but the forward-looking forecast must use the meter reading data...

I would ignore what Tado says, estimating and averaging is bound to give incorrect information.

 

[MNW67]

I have Tado trvs on all radiators except the towel rails in the bathrooms (which have traditional trvs).

Tomorrow, when there is noone at home I will turn off the boiler and measure the actual usage via meter reads when turned on from cold.

How cold was it for the period of the screenshot? When was the screenshot period? I could check mine for a comparison?

 

[Mister Banks]

Here is a screenshot from my Octopus app. I turned off the boiler at about 10am for a couple of hours so you can see zero usage until I turned it back on. The boiler is installed in the garage so was cold before I turned it back on. However the gas usage only peaked to about 10 kWh as you can see from the picture.

That looks like your smart TRV's are calling for heat all day long!

 

[fourtytwo]

I have Tado trvs on all radiators except the towel rails in the bathrooms (which have traditional trvs).

Tomorrow, when there is noone at home I will turn off the boiler and measure the actual usage via meter reads when turned on from cold.

How will you "turn off the boiler" ?
The frost stat will overide any timer(Tado) settings and it is not advisable to let your external (garage) boiler freeze