I deleted the first post and replace it with one with the correct units ft^3.
Sorry to cause confusion - should have just posted a correction!
To the OP - if the bill says 1200 kwh then use that to produce a conversion factor from "your" units to kwh.
Gas tariffs are in kwh.
That converts from 100's of ft^3 to m^3. I take it they did not apply this step to your readings then? (this is a not uncommon source of billing errors - converting readings already in m^3 to metric.
I just happen to have some figures to hand from our place I can plug in... Large Victorian place in exposed location, solid walls etc, with stone age Ideal Mexico boiler (balanced flue at least!):
So using that description, for the 28 days from 19th Mar to 14th Apr we used 83 hundred ft^3. So using that conversion we get 83 * 2.83 *
1.02264 * 39.212 / 3.6 = 2616 kWh or about twice your consumption - although that was a month earlier in the year when the heating would have still been on a little. It represents a usage of about 320 ft^3 / day. For the last 39 days the average is 70 ft^3 / day (no heating, just water heating). Our peek use in the coldest bit of the year was up to 580 ft^3 per day.(ToDo list: solid wall insulation, zone heating, change boiler!)
The bill with its 1263 kWh seems to me consistent with the OP's reading of 111 cu. m. I cannot see a factor 10 error anywhere.
1263kWh initially struck me as quite a lot given the heating was only on for 3 days but I then wondered about water heating for 5 residents and 2 visitors. How many baths? showers? (I think a bath can take 5 to 10 kWh but that's from my memory which is even less reliable than Apollo 11's LEM computer.)
At least two showers a day and the guests were here for two days and also had showers, heating flow temperature was only around 60C IIRC and only one zone. No baths taken.
I remembered that just before I hit send which is why I re-typed the information as a table in the original message. I then forgot to remove the binary attachment picture anyway...
Strange how you get used to using attachments in messages all the time and have to consciously think not to on usenet!
And the ironic (in the Alanis Morissette sense of the word) thing is, I've told people off for posting binaries on usenet before :o)
We have an almost identical meter and a Vaillant combi boiler are using similar amounts of gas for a similarly-sized house.
17 Jan to 7 Feb this year we used 338 units as indicated by the meter etc.The bizarre thing is, we moved from an old house to a newer house.
The old house had a very old Baxi wall-mounted boiler which although had a lower power output than the Vaillant it seemed to heat the house up much much quicker.
KWh Last Year This Year Jan 90 230 Feb 90 235 Mar 70 175 Apr 60 120 May 40 70
I have no idea why our current boiler uses so much more gas than our old boiler...
I guess most of the heat from the gas is going out of the flue...
I assume no gas is used for cooking ?
My valliant has an option to keep a small amount of hot water heated and ready for use. This is activated/deactivated by turning the HW temp dial fully up then down to the required temp ( I use 50C) A "C" appears in the display when this is activated. My impression is that this option uses less than 1kwh per day.
Our boiler has two tanks at the back which store water at a minimum of
50C, when the tanks are fully charged you can enjoy hot water at 20l/ pm for 10 minutes, once the tank is empty the flow rate drops to 15l/ pm, it takes two minutes for the tanks to fully recharge.Do you think that the undersized radiators are causing high gas usage?
In winter, especially on cold days the house will struggle to reach
19.5C with a flow temperature of 82C.
What model do you have?
That is exactly the theory I have about my similar tale! We see very similar symptoms.
That is exactly the theory I have about my similar tale! We see very similar symptoms.
It's a 28KW Turbomax
Ah - can't remember the last time I felt a hot woman. Sorry. But you must be losing a lot of heat up through the loft hatch and the uninsulated roof.
The 28kw hot water model?
Either way, our boiler has a lot of power but it's not being used, I reckon the boiler is spending too much time getting the house up to temperature.
I understand what you mean.
No, ours is a combi. Now we're not using the heating as summer is (theoretically) here, we are only using the hot water and the gas usage seems to be dropping to more "normal" levels.
But when we were using the heating the house would take ages to warm up and some parts (including the area where the thermostat was located) would struggle to get warm enough. The boiler was on pretty much constantly and radiators would be red-hot but the house not getting particularly warm in many places (except the bathroom which has a normal radiator and a towel radiator).
I think the radiators are undersized (or there are not enough of them).
Yes I know it's a combi, but what are the hot water and heating outputs?
E.g. ours has a 28kw heating output and 37kw hot water output.
28 kw is plenty for heating but there are just not enough radiators/ big enough radiators to dump the heat.Yes, in summer we are seeing more "normal levels"
I'm just worried that changing the radiators to properly sized ones might not make a difference!
Exactly what happens at our house, except the boiler can't stay on constantly because the Honeywell cycles the boiler when the temperature is close to the set point to prevent overshoot.
I think you are right!
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