How accurate are the In-Home Display (IHD) readings?

  • 10 November 2020
  • 10 replies
  • 106 views

I had a new boiler installed a few months ago and was keen to find out how much more efficient my gas usage was going to be this year compared to last year. I have my In-Home Display set up in the kitchen so I am always aware of my daily consumption and spend and I kept a close eye on the month of October as that was when I really started to use the boiler and thought analysing my October 2019 bill with October 2020 would be a good comparison.

Throughout the month of October the IHD showed that my gas usage was low, and when I compared it to the figures the IHD had on record for 2019 I thought I would be making a real saving this month.

I have attached a photo to show the IHD readings that I was being given and it shows the summary for October 2019 and October 2020. The IHD shows that my gas usage during October 2020 was much much lower than Oct’19.

I must admit to being pretty disappointed to receive my Energy bill for this month showing that my spend on gas has actually gone up during the month of October! It went from £32.62 in Oct’19 to £36.96 in Oct’20. 

Now, I appreciate the rise is not going to break that bank, but it leads me to question - what is the point of having a smart meter and an In-Home Display unit if the data it shows is not accurate?

 


10 replies

Hey @myauntie 

Could it be down to a difference in unit rates for your gas since last year? It may have been slightly more expensive per kWh this October! 

That’s a huge change between the Octobers! I can’t believe a more efficient boiler would explain that. Surely there’s a glitch in the graph?

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@myauntie 

Do you have actual dated readings to check the ihd against? As said the rates will affect the ihd chart, Also I suspect but I don’t know for sure that the ihd is only a guide because it doesn’t know the calorific value of the gas supplied when it’s supplied, it only knows the volume. The calorific value of the gas will affect the charges it could easily vary by more than 2%

I appreciate the ihd at a glance does look anomalous, but I’d also say that a difference of £3 in a random month is meaningless, a degree or two in outside temp difference could easily cause that sort of difference. You’ve based an opinion on one random measurement.

This is interesting, if you don’t have a life or you’re a nerd (I’m sure neither apply to you  but sadly both apply to me) I’d be taking accurate (volume) meter readings at the same time every day for a couple of months and checking the ihd against those. Only then will you be able to judge what’s going on.

I’m not denigrating what you’ve written and I’m absolutely sure of one thing, if the replacement boiler has a better efficiency than the one it replaced, then FOR THE SAME HEAT OUTPUT you will use less gas. But life, weather,  how you feel and how long you spend in the house all conspire to muddle that.

 

That’s a huge change between the Octobers! I can’t believe a more efficient boiler would explain that. Surely there’s a glitch in the graph?

Or, the IHD stopped updating in early October. See November is also completely empty (or you’re very cold)!

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I wouldn’t rely any of that ihd chart, what does it do if it loses connection for example?

Hey @myauntie 

Could it be down to a difference in unit rates for your gas since last year? It may have been slightly more expensive per kWh this October! 

Thanks @Nataly, I have compared my readings from Oct 2019 and Oct 2020 (see attached) which shows the price p/KWh is lower this year but I have actually consumed more. However, throughout Oct my IHD indicated I was using less throughout the entire month, hence my post.

 

That’s a huge change between the Octobers! I can’t believe a more efficient boiler would explain that. Surely there’s a glitch in the graph?

This is what I have been trying to resolve with PurePlanet for the last week but am not really getting anywhere (see https://community.purepla.net/ask-the-community-15/anyone-from-the-smart-team-available-11548?postid=67874#post67874

They’ve closed my Wattbott chat and no one is getting back to me via email so as it stands, my current IHD is pretty useless.

Here’s an updated shot from this morning showing that the month of November has hardly moved even though it has been registering readings throughout the week.

 

 

@myauntie

Do you have actual dated readings to check the ihd against? As said the rates will affect the ihd chart, Also I suspect but I don’t know for sure that the ihd is only a guide because it doesn’t know the calorific value of the gas supplied when it’s supplied, it only knows the volume. The calorific value of the gas will affect the charges it could easily vary by more than 2%

I appreciate the ihd at a glance does look anomalous, but I’d also say that a difference of £3 in a random month is meaningless, a degree or two in outside temp difference could easily cause that sort of difference. You’ve based an opinion on one random measurement.

This is interesting, if you don’t have a life or you’re a nerd (I’m sure neither apply to you  but sadly both apply to me) I’d be taking accurate (volume) meter readings at the same time every day for a couple of months and checking the ihd against those. Only then will you be able to judge what’s going on.

I’m not denigrating what you’ve written and I’m absolutely sure of one thing, if the replacement boiler has a better efficiency than the one it replaced, then FOR THE SAME HEAT OUTPUT you will use less gas. But life, weather,  how you feel and how long you spend in the house all conspire to muddle that.

 

I’m with you @woz, I was expecting this month’s bill to be much higher, especially considering I have been working form home since March! However, the IHD meter readings made it seem like I was saving a fortune. 

I thought the whole point of the smart meter and the IHD were for Pure Planet to get their monthly reading automatically, and for me to be aware of how much I’m using at a glance - I don’t really want to crawl into my cupboard to compare the gas meter reading with the reading on the IHD.

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To be honest, the graphs on the IHD are pretty useless, it gives a value for the highest reading, but without some sort of scale the other bars are not very informative, it just tells you that you have used less than the highest value This goes for the yearly, monthly and daily usage grsphs

That’s a huge change between the Octobers! I can’t believe a more efficient boiler would explain that. Surely there’s a glitch in the graph?

This is what I have been trying to resolve with PurePlanet for the last week but am not really getting anywhere (see https://community.purepla.net/ask-the-community-15/anyone-from-the-smart-team-available-11548?postid=67874#post67874

They’ve closed my Wattbott chat and no one is getting back to me via email so as it stands, my current IHD is pretty useless.

Here’s an updated shot from this morning showing that the month of November has hardly moved even though it has been registering readings throughout the week.

 

 

Yup, there’s something clearly wrong there. Keep being the squeaky wheel @myauntie. PP will have to oil you eventually.

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