Electric usage when not in...

charlotte289

Hello,
I had a little query relating to my electricity usage over Christmas this year, and was wondering if it was what I should have expected or not. Basically, I was away from my flat for 8 days over Christmas, and left the bedroom oil heater on its 'low' setting (800W?) and at the 'frost-protect' thermostat setting. Nothing else was on, except the fridge. Yet when I came back, the meter showed 100 units had been used, and that's not much less than what I'd have used if I'd been in! It's not even like it was cold over that period...

Should I have attached one of those mains timers to the heater instead of using that setting, or has my meter been acting up? If the 'certified' stickers are right, it's from 1993 and the timeswitch is from 1985... are meters supposed to last that long?

Thanks!

HappyMJ

charlotte289 wrote: »

Hello,
I had a little query relating to my electricity usage over Christmas this year, and was wondering if it was what I should have expected or not. Basically, I was away from my flat for 8 days over Christmas, and left the bedroom oil heater on its 'low' setting (800W?) and at the 'frost-protect' thermostat setting. Nothing else was on, except the fridge. Yet when I came back, the meter showed 100 units had been used, and that's not much less than what I'd have used if I'd been in! It's not even like it was cold over that period...

Should I have attached one of those mains timers to the heater instead of using that setting, or has my meter been acting up? If the 'certified' stickers are right, it's from 1993 and the timeswitch is from 1985... are meters supposed to last that long?

Thanks!

Why did you leave the oil heater on? Mine is 800W and uses about 400W every hour as the thermostat turns it off and on. That would be about 80kWh in 8 days plus the fridge could make it 100kWh in a week quite easily.

charlotte289

HappyMJ wrote: »

Why did you leave the oil heater on? Mine is 800W and uses about 400W every hour as the thermostat turns it off and on. That would be about 80kWh in 8 days plus the fridge could make it 100kWh in a week quite easily.

I left it on in case the pipes froze up... the hot and cold water tanks are in the bedroom. Just typically, though, it wasn't very cold... I'd assumed that the frost-protect thing would only turn on when the temperature was close to freezing, but obviously not!

HappyMJ

charlotte289 wrote: »

I left it on in case the pipes froze up... the hot and cold water tanks are in the bedroom. Just typically, though, it wasn't very cold... I'd assumed that the frost-protect thing would only turn on when the temperature was close to freezing, but obviously not!

They would only freeze up if the temperature drops below -5 degrees for more than a few days in a row.

charlotte289

HappyMJ wrote: »

They would only freeze up if the temperature drops below -5 degrees for more than a few days in a row.

But I didn't know it wouldn't The forecasts only seem to be accurate for 3 days ahead, but I was going away for 8 so I didn't know if it'd be cold at night or not!

victor2

I'd say the bulk of your usage is from the oil heater too - a timer on that would have been smarter, as well as having it on the lowest setting.
My fridge/freezer uses just over 3kWh per day when running in an empty house - full of food and not being opened of course. But having said that, they can vary a lot depending on the temperature they are set at, the size and how much is stored in them.

jalexa

charlotte289 wrote: »

I was away from my flat for 8 days over Christmas, and left the bedroom oil heater on its 'low' setting (800W?) and at the 'frost-protect' thermostat setting.

If you deliberately left it on the frost-setting as a frost protection measure while away, then I commend you even if severe cold wasn't forecast. You were entitled to a better performance from the thermostat. A small price to pay to avoid frozen pipes. Though possibly the kitchen might have been a better location.

In my experience the frost setting of oil-filled radiators generally isn't very accurate, much higher than is necessary for frost-protection. Personally I wouldn't bother with a timer to save a pound or too, just something to go wrong. Although it may not pay for the odd occasion a Dimplex Coldwatcher performs better at the frost setting.

As I type this I see you have replied about the location of the tanks. So instead of the "kitchen" I would say the lowest location and leave the doors slightly open. If there are pipes in an attic it is recommended to leave the hatch ajar.

Perhaps your concern is the accuracy of the meter. Unlikely to be wrong but fairly easy to check with an appliance of known rating. Your heater switched to full over a 15 or 20 minute period or whatever period you can get without the thermostat clicking off would allow you to calculate. You mention a "timeswitch". Why is there a timeswitch?

BTW are you *certain* nothing else was on?

charlotte289

victor2 wrote: »

I'd say the bulk of your usage is from the oil heater too - a timer on that would have been smarter, as well as having it on the lowest setting.
My fridge/freezer uses just over 3kWh per day when running in an empty house - full of food and not being opened of course. But having said that, they can vary a lot depending on the temperature they are set at, the size and how much is stored in them.

That'll probably be right... my fridge freezer is just a little one, so I don't imagine it'll be using much. Oh well, next time I'll know...

jalexa wrote: »

If you deliberately left it on the frost-setting as a frost protection measure while away, then I commend you even if severe cold wasn't forecast. You were entitled to a better performance from the thermostat. A small price to pay to avoid frozen pipes. Though possibly the kitchen might have been a better location.

In my experience the frost setting of oil-filled radiators generally isn't very accurate, much higher than is necessary for frost-protection. Personally I wouldn't bother with a timer to save a pound or too, just something to go wrong. Although it may not pay for the odd occasion a Dimplex Coldwatcher performs better at the frost setting.

As I type this I see you have replied about the location of the tanks. So instead of the "kitchen" I would say the lowest location and leave the doors slightly open. If there are pipes in an attic it is recommended to leave the hatch ajar.

Perhaps your concern is the accuracy of the meter. Unlikely to be wrong but fairly easy to check with an appliance of known rating. Your heater switched to full over a 15 or 20 minute period or whatever period you can get without the thermostat clicking off would allow you to calculate. You mention a "timeswitch". Why is there a timeswitch?

BTW are you *certain* nothing else was on?

I'd have expected better from it too... I'd never used the setting before so I had no idea how much it would use.
In case you're wondering about the the timeswitch, the flat is wired up for Economy 7 but I don't use it, as the input dial on the storage heater is knackered and I'm out of the house a lot anyway... so I'm on a non-E7 tariff with British Gas.

rogerblack

victor2 wrote: »

My fridge/freezer uses just over 3kWh per day

That is _extremely_ high.
Is it a truly massive and rather inefficient unit?
My _very_ large chest freezer, and fridge together use under 1kWh.

victor2

rogerblack wrote: »

That is _extremely_ high.
Is it a truly massive and rather inefficient unit?
My _very_ large chest freezer, and fridge together use under 1kWh.

It's almost 20 years old and is a US made General Electric large upright monster. Made in the days when power consumption didn't really matter.
Rating label says it uses 350W and has a 750W defrost heater, which seems to kick in about once every 10 hours. I can tell from a glance at my energy monitor when the fridge compressor is running, which it seems to do for about 20 minutes an hour.
Would be expensive to replace, will probably run forever and we love it - even had the kitchen built round it!