High energy usage in the early hours - what's the cause?

Hi @holliesavage ,

The most likely culprit I can think of is either water heating or central heating. Can you show us some screenshots of the usage data please?

My water heater doesn’t come on until 6am and goes off at 9am it’s on a timer and we don’t have central heating as we are an all electric flat so have those electric radiators but we don’t use them.

Hmm… That’s really weird…

I’ll have a think about this one and let you know. I’ll probably also grab a few friends too if that’s OK?

Amazing thank you any help would be appreciated! It’s just really strange and concerning as to why my usage is that high when we’re asleep! 

Something is happening at around 3.40am.

It’s using around 3kW constantly until morning.

This would tie in with the power of an immersion heater.

First thing I’d check is whether the time on the timer for the water heater is correct.

@holliesavage Looking at the log of use, you might have to do some detective work. As @nealmurphy mentions, the timer on the water heater is a prime suspect. Other than that, you may need to try turning off certain items to pick up what it is that’s consuming the power. 
Is there a point at which the power use goes back to ‘normal’?

Neal wrote:
This would tie in with the power of an immersion heater. First thing I’d check is whether the time on the timer for the water heater is correct.

I second this. There is an antidiluvian timer on the immersion heater here which is set on installation to be switched on for a few hours (five or six, I think) each night. The heater turns off when the thermostat tells it that the water is hot enough.

Its built-in clock has to be corrected after each power cut, and adjusted for summertime each year. So if you recently had some electrical work done (installing a smart meter, perhaps?) that involved switching off the power meanwhile, your timer is probably out by the amount of time the power was off for.

The on-hours are designed to be in the middle of the (7-hour) off-peak period, so if the clock does stop for a bit for whatever reason, the heater doesn’t operate out of off-peak hours when power is cheaper. This is probably irrelevant nowadays, if the primary heater is fed from a dedicated off-peak circuit which makes sure that the power-hungry things like water heaters and storage radiators just won’t heat during expensive hours. 

Yeah, usually a Smart Meter upgrade lasts for around an 30-60 minutes per meter for a simple straight swap, but it can take two hours in some cases.

I’d agree with the comments above. Either a single power cut (or several shorter ones!) might have knocked a timer out of sync because that’s the only logical explanation I can think of.

I’m still running through other scenarios too! I’ll let you know here if there’s any others I can come up with.

We had our smart meter fixed in august as it had stopped working and they came to fix it then I was with SSE at this time.

we haven’t had any power cuts that we know of or any major electrical work done either.

My water heater timer goes on at 6am and goes off at 9am that’s enough hot water for us for the day as we are an all electric flat we have a tank for our hot water and no central heating.

Firstly, @Firedog gets a like for brilliant use of the word antidiluvian!

In terms of power cuts, if it was an analogue clock and there was a power cut the timer would think that it was earlier than it actually was, so the heating would be coming on later than programmed. If digital it may have reset to midnight when the power was restored. So if power was restored at around 21:45, it could mean the timer was running 2hrs 15mins fast and sticking the heating on at 03:45 thinking it was actually 06:00.

Can we see your 30 minute usage graphs for 6am onwards please to see how much power is being drawn then?

@nealmurphy this is the type of timer our hot water heater has if that’s any help?

@nealmurphy i think this is what you wanted this is from Sundays usage

That's perfect @holliesavage 

Can you confirm that the little triangle on the dial is pointing to the correct time? I reckon the dial has been knocked out of sync. If so, it just needs turning to the correct time. If it's not this we will move to plan B 

@nealmurphy yeah it’s on the correct time the only time I’ve ever changed it is when the clocks go forward or back

I think you need to start eliminating things .. if you can bear it @holliesavage turn the hot water heating off overnight. The next days result will show if that’s a cause. Given the time the higher power is recorded, it still seems the most possible cause. 

@BPLightlog 

Thank you I’ll give that a go and see if that’s the cause of the high usage.

I checked my usage this morning for yesterday and it was still the same timing and my hot water time is on from 6 til 9 still.

can I ask if my heater comes on at 6am the usage is high then on the graph but is low at 9am is that because at 6 it starts kicking in?

So I’m planning on turning my water heater off tonight and seeing if that makes a change on my usage.

I have looked on my OVO app at usage for yesterday and it has dropped but I haven’t done anything different! Also there is a section that says most of my electric is on entertainment and computing so I’m confused🤷🏻‍♀️

Hmm, ok @holliesavage 

It looks like there is still a high level but for a shorter time. If this disappears altogether then that could still point to the water heater. Did you perhaps not use as much hot water during the previous day? 
I’m not completely sure but I think that the usage type is pulled from an electrical ‘signature’ logged from the Wi-Fi connection on your system - also notice the date range which says 3rd to 9th October so I’m not sure it relates to the peak shown. 
It will be really interesting to see the results as well as hopefully helping you understand/reduce your energy draw. 

Close! :)

The electrical signatures are indeed part of the algorithm, but it’s based off of data directly from the electric meter rather than anything else.

I wouldn’t take seriously anything that energy insights usage graph says. Seemingly I use most of my gas for ‘water heating’ when my only gas appliance is the hob.
I would imagine your timer for the immersion is just not as accurate as you expected it to be. It may look like it’s set for 6am but it’s actually switching on at 3:45  You say you have enough hot water for the whole day by heating it as it is now, so no need to change anything.

What’s the verdict, @holliesavage? Did this have an impact?

Spot on Julia. The idea of a useful “signature” coming from energy consumption data that has a resolution of 30 minutes, which is all the meter data used by energy insights has access to, is laughable. (It’s a shame that gas data is limited to that 30 minute resolution, unless you have a robot pressing buttons and reading the meter display - I have been that robot in the past…)

There are devices that can remotely access and record the 10 second data which the electricity meter generates (and which is shown, fleetingly, on the In Home Display). At that level one really can distinguish the signatures of (non-modulating) fridges and freezers, security lights coming on briefly when triggered by leaves blowing in the wind, an immersion heater coming on solidly and then intermittently as the water temperature approaches the set value, etc.

I don’t have one of those devices, but I can see equivalent information from my Open Energy Monitor set-up, which makes its own independent measurements of the supply voltage and total current drawn. It’s very revealing and, for instance, prompted me to replace an ageing lead-acid battery by a compatible lithium-iron phosphate battery. At a stroke, the home security system’s annual running cost (at the new “capped” tariff) dropped from just over £150 to about £20. The new battery will pay for itself inside 4 months.

Hi everyone!

So it is my water heater that’s causing all the electric usage I turned it off Friday night and I’ve checked my usage today and it’s less than what you t normally is!