# Water meter

Posted 17th Dec 2019
This is the water meter in my apartment - would leaving it on standby (the middle of the long dial) still use electricity, even if the switching riders aren't set to heat the water up?

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That's an immersion heater timer, not a water meter, and it probably cost 10p a year to power.
It will still use electricity to work the clock for the correct time
Doh
That's a mechanical timeswitch powered by 240V mains. Similar devices consume about 25 milliWatt/hr per day in idle mode, so say total 9kW/hr over one year where each/one kW/hr may cost 20p. Remove the mains and the device clock will stop and consume zero power.
Happy for someone to check that maths !
That's an immersion heater timer, not a water meter, and it probably cost 10p a year to power.
AndyRoyd17/12/2019 12:32

Happy for someone to check that maths !

I made that 0.22Kwh over a year, so less than 5p using your figures.
melted17/12/2019 13:29

I made that 0.22Kwh over a year, so less than 5p using your figures.

Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year = 25 x 365 = 9125W/hr = 9.125kW/hr
AndyRoyd17/12/2019 13:38

Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year …Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year = 25 x 365 = 9125W/hr = 9.125kW/hr

You said milli Watt / hour

25mW/h / 1,000,000 x 24 hours x 365 days = 0.219 units (KWh)
Edited by: "melted" 17th Dec 2019
AndyRoyd17/12/2019 13:38

Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year …Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year = 25 x 365 = 9125W/hr = 9.125kW/hr

25mw * 24 hours = 600mw

600mw * 365 = 219000mw = 219w a year

4 or 5p a year.
So the consensus is that it uses electricity but hardly any?
jam-tart17/12/2019 14:10

So the consensus is that it uses electricity but hardly any?

Exactly so, it is just a little, very low power, synchronous motor, I think.
Edited by: "melted" 17th Dec 2019
melted17/12/2019 13:49

You said milli Watt / hour25mW/h / 1,000,000 x 24 hours x 365 days = …You said milli Watt / hour25mW/h / 1,000,000 x 24 hours x 365 days = 0.219 units (KWh)

andymagic17/12/2019 14:01

25mw * 24 hours = 600mw 600mw * 365 = 219000mw = 219w a year4 or 5p a year.

25W / day > 25W x 365 days a year = 9kW/h per year. Annual cost to run 24/7/365 will be user's unit cost per kWh x 9.
Ha, so my maths was correct, but original description rubbish. The device is rated to consume circa 1Watt per hour, so the concept of milliwatts should have read millikilowatts, whatever that is. Apologies for the original misleading ramble guys !
AndyRoyd17/12/2019 16:04

25W / day > 25W x 365 days a year = 9kW/h per year. Annual cost to run …25W / day > 25W x 365 days a year = 9kW/h per year. Annual cost to run 24/7/365 will be user's unit cost per kWh x 9.Ha, so my maths was correct, but original description rubbish. The device is rated to consume circa 1Watt per hour, so the concept of milliwatts should have read millikilowatts, whatever that is. Apologies for the original misleading ramble guys !

Cheers, still a bit off though buddy, 24 hour days and all that
If you're looking to have more control and save some money on your water heating needs, maybe a WiFi enabled immersion switch could help you, ideal for ever changing scedules
An example here amazon.co.uk/Fre…LFJ
AndyRoyd17/12/2019 13:38

Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year …Mmm, here's my presumably rubbish thinking: 25W/hr per day, so over a year = 25 x 365 = 9125W/hr = 9.125kW/hr

Milli what and what big difference
MynameisM18/12/2019 14:21

Milli what and what big difference

That's watt I was thinking, hence the suggestion of millikilowatts.