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Discuss How to quantify bills from additional electric radiator in the Central Heating Forum area at

  1. Bettyboo

    Bettyboo Member

    My prospective lodger wants to bring a radiator with him. (He's Greek and likes warm environment in his bedroom.)
    Does anyone know how I would quantify extra electricity used and costs please?
    Currently have gas heating
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    found out whats the usage per hour
    estimate how many hours a day he would want it on for
    x that by your elec price per kw
  3. Ric2013

    Ric2013 Plumber Top Contributor!!

    You can get plug-in electricity meters, but the only one I've ever seen was so inaccurate, you may as well have put a finger in the air and chosen a figure based on the wind speed.
    You could go by the number of run hours and the kW of the heater, but they often cycle on and off... what sort of electric heater is it though?
  4. Bettyboo

    Bettyboo Member

  5. Murdoch

    Murdoch Active Member

    Making some assumptions:

    2Kw heater (per example shown)
    16p per kw
    Hours per day 1

    1.5 x 0.16 * 1 * 365 =£116.80

    Divide by 12 = £9.73 per month

    EDIT : You need to remember he is "topping up" your heat rather than heating an empty room
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  6. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    yea need to know the power rating on it and how long each days its going to be on for

    or charge 20 a month
  7. Bettyboo

    Bettyboo Member

    Wow! thanks for calculation, but how do I know how often he has it on!!
  8. Ric2013

    Ric2013 Plumber Top Contributor!!

    Could be worse. At least that should run at the rated output, when it's not being switched off by its thermostat. So it's kW rating times hours run. But what if it's going on and off on its thermostat, or not running on full power (they usually have a couple of switches). At this point, a proper test meter wired in might be your best bet.

    I do have an old electricity meter myself that has two leads - a plug on one and a socket on the other, but this is not truly safe as it's not designed to be used in this way, and if you have a lodger, you'd need to have this sort of thing done safely and to standard. But it may not cost a fortune.

    If your own electricity consumption is steady and a known quantity, you could simply compare the costs before and with lodger and get a reasonably accurate idea of how much you need to charge this lodger to not be out of pocket?
  9. Murdoch

    Murdoch Active Member

    You won't and that would be almost impossible to know and hence why my calculation was meant to show the annual effect on your bills.
  10. Best

    Best Trusted Plumber Top Contributor!!

    The stat on the heater will cut it on and off, so it is variable and won't use 2kw per hour.
    An old type bar fire is different because it would just put out same power while on and very heavy on electric.
    You could buy a clip on power meter now and test all your appliances power draw. You just set them for pence per kw and they them tell you pence you are using for that hour.
  11. Bettyboo

    Bettyboo Member

    Hi Best...I don't think I'm up to doing what you
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  12. Bettyboo

    Bettyboo Member

    With internet of things etc you would think it would be easier nowadays to calculate , but thanks guys for your thoughts:)
  13. Ric2013

    Ric2013 Plumber Top Contributor!!

    Never easy to calculate, even with the internet of things. It's like my asking you to try to calculate how much diesel I've used in my van in the last month without knowing how many miles I've driven, what speed, and what load is being carried. You won't get anywhere close to an accurate answer.

    For you, the cost could be anywhere between almost nothing and 24x the figure Murdoch has suggested (the very worst case scenario is that the heater is run at full 2kW rating and that neither the lodger, nor the thermostat, ever switches it off).

    Personally I'd just make a guess of what he'll cost you (as Shaun suggested) and then change the rent if need be.

    FWIW, I spent a year in a large static caravan (including all but 6 weeks of winter) and spent about £100 on electricity. Heating was almost entirely by electricity. But it wasn't that warm.
  14. CHRISX

    CHRISX Active Member

    Hello Betty,

    Good replies from the Members above - basically without knowing how many hours of use it would be impossible to calculate even an approximate cost for the Electricity used.

    The reply by Member ric2013 included a good comparison of how it would be impossible to calculate how much Diesel his Van used without knowing various details including the mileage.

    Member Murdoch`s message gives a good approximate calculation [re. KW Hour cost possibly being different] for a 2 KW Heater thermostatically controlled usage per hour.

    However your prospective Lodger might be using the Heater for 5 or 6 hours per Day / Night.

    And he might not just be `topping up the Central Heating` in his room - He might be using the Electric Heater for hours on Days / Nights when You don`t have the Heating On.

    I have some Cypriot friends and a Cypriot Barber they often have family and friends over from Cyprus - even in our mid Summer I have heard them commenting on how `Cold` it is here.

    Having been to Cyprus 13 times on Holiday where it has almost always been at least `32 to 38 degrees` during June, July, August and September I can see how our average Summer temperatures of 20 to 22 degrees would seem `Cold` to them.

    Imagine how someone from Greece, Cyprus or a similar `Hot Country` [in Summers] would find our Winter temperatures - although it does get `Cold` in Cyprus and Greece during the Winter so they would have experience of perhaps our `Mild Winter` temperatures.

    Good Luck with sorting this out.


    Last edited: Feb 8, 2018
  15. Best

    Best Trusted Plumber Top Contributor!!

    I say forget the Greek guy, - get a lodger from Iceland. ;)
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