Advice please - how much energy do our heaters use?

The_Boss

Hi all,

We currently heat our flat with 3 DeLonghi RTR2000 electric radiators (no gas connection to our flat) and I have a question about their energy use while waiting (still!) for our energy meter to arrive from British Gas.

These heaters are 2000 watt outputs. They have an adjustable thermostat and two heat settings - and this is the bit that has confused me. The guidelines do not contain details relating to the heat output on each of these, but from online research, seemingly The higher (hotter) setting is apparently 1100 watts and the lower setting 900 watts.

I thought with a 2kw heater we'd be using 2kw per hour used (assuming on constantly for an hour at highest thermostat setting) but given the settings on this heater are seemingly 1100w and 900w, how much would the energy use be per hour on each of these settings assuming thermostat at highest setting/heating on solidly for an hour? 1100w and 900w respectively, or 2000?

Nada666

Are you sure there aren't three settings? They have a 2000, 1100, 900 W model.

Nada666

Or is it a switches style - is there an 1100 W switch, a 900 W switch, both switched down - 2000 W?

The_Boss

Definitely only two settings. Only one lever type switch. Middle placement is off, lever down is the hotter setting and lever up is the lower setting.

Plus the thermostat which switches it on and off according to temperature.

MeterMan

by definition.

If the switch is at the 900w position, then it would use a maximum of 900wph, and same again for 1100w position. In theory at least anyway.

victor2

The_Boss wrote: »

Definitely only two settings. Only one lever type switch. Middle placement is off, lever down is the hotter setting and lever up is the lower setting.

Plus the thermostat which switches it on and off according to temperature.

The manual is praticularly(sic) unhelpful isn't it...

Insert the plug into the mains socket and switch on turning the thermostat knob clockwise until it can be turned no further, then position the switch up in the I position (minimum power) or down in the II position (maximum power).The indicator light will come on.
We suggest that on days when temperatures are not praticularly cold. Select minimum output to optimize savings on energy consumption.

As it claims to be a 2KW heater, I would guess that in position I, just one (900W?) element is on, and in position II, the 900 and 1100W elements are on, as you would hardly notice the difference between 900W and 1100W.
Quick test is to look at your electric meter with the heater on I then II. Depending on the meter type (digital or analogue), the pulses or revolutions of the disc would be around twice as fast in a 2KW mode, or hardly any difference if it really is switching from 900W to 1100W.

macman

But assuming that the 'stat is working, it doesn't cost you any more to use it on the higher power setting. It will just bring the room up to the set temp level more quickly, and the shut off. The running cost will be the same on any power setting if the 'stat setting is the same.
1 hour on 900W will use 0.9kWh, one hour on 1100W will use 1,1kWh, assuming full output.

The_Boss

macman wrote: »

But assuming that the 'stat is working, it doesn't cost you any more to use it on the higher power setting. It will just bring the room up to the set temp level more quickly, and the shut off. The running cost will be the same on any power setting if the 'stat setting is the same.
1 hour on 900W will use 0.9kWh, one hour on 1100W will use 1,1kWh, assuming full output.

But how is it a 2kw heat output then? I use the word thermostat when actually it is an adjustable level from setting 0 to setting 7 rather than a designated temperature ( and it definitely doesn't get as hot on the lower setting).

chopps

On high setting it will most likely be 2kW and 0.9 kW on low.

If it's a normal air operated bimetallic strip type thermostat you will hear it click on and off as you rotate it clockwise/anti clockwise. It's either on or off so switches 0.9kw or 2kW. The numbers are just a guide as it's not a fully variable control which would adjust the power consumption over the full range from zero to 0.9 or 2 kW.
Microwave ovens are similarly confusing in that the power setting (low /med / high ) is only a timer altering the on/off timing of the magnetron which can only be in an on or off state.

[Deleted User]

If it's the size of your next electricity bill that's worrying you, then it's the insulation of the building and inside/outside temperature that will tell you, NOT the maximum power of the heater.