Really inefficient boiler?

hotcookie101

I have a combi boiler, which has been on hot water only since april ish (but was broken and not switching off so will do readings from june/july when fixed)
From 30th July to 13 sept we used 27 units. From 13th sept to today we used 25 units :eek: :eek::eek:we have had the heating on for a couple hours each day for 3 days. Could it really make that much difference?

(it did for a few days have the valve that puts more pressure in the system left ever so slightly open so water overflowed in the overflow valve and pressure was over 3, but only for a few days)

Am terrified that we are going to use MASSIVE amounts of gas over the winter, never mind our electric consumption which is usually around 18kwh per day :eek:

Magentasue

We are high users with a combi boiler. For August, we averaged 13units elec a day. This was not without effort but didn't involve sacrifices.

Gas averaged 24kwh a day - hot water and cooking only.

gmatwork

hotcookie101 wrote: »

I have a combi boiler, which has been on hot water only since april ish (but was broken and not switching off so will do readings from june/july when fixed)
From 30th July to 13 sept we used 27 units. From 13th sept to today we used 25 units :eek: :eek::eek:we have had the heating on for a couple hours each day for 3 days. Could it really make that much difference?

(it did for a few days have the valve that puts more pressure in the system left ever so slightly open so water overflowed in the overflow valve and pressure was over 3, but only for a few days)

Am terrified that we are going to use MASSIVE amounts of gas over the winter, never mind our electric consumption which is usually around 18kwh per day :eek:

Yes I think it could. A combi boiler on 'hot water only' will operate only when you turn the hot tap on. Once you turn the heating on it will fire until the house is up to temp, and then at regular intervals to keep it there. You will also however have wasted some hot water if the safety valve was blowing for 3 days and the heating was on. You need to check again with the system running properly to get a true consumption reading.

Cardew

Firstly it depends on what type of Gas Unit you mean.

If you have an Imperial meter(1 unit is 100 cubic feet) 25 units is approx 780kWhs.

If a Metric meter(1 unit is 1 cubic meter) 25 units is approx 280kWh

So with gas at 3p/kWh 25 units is either approx £23 or £8

hotcookie101

Thanks, the meter is m3, today it reads 3 units more than yesterday :eek: :eek: :eek:
Is it just me or does that seem ridiculous for hotwater and about 3 hours of heating?

Magentasue

hotcookie101 wrote: »

Thanks, the meter is m3, today it reads 3 units more than yesterday :eek: :eek: :eek:
Is it just me or does that seem ridiculous for hotwater and about 3 hours of heating?

I think conversion for metric is approx x11 so that would be about 33kwh?

As I said, we've been using 24kwh a day without heating so that's about 9kwh or about 10p an hour for heating. Sounds good to me!

We've been putting the heating on this week but only read once a week. Just had a look and we've used 6 units since Monday morning so that's:
6 x 33.1 = 199kwh = 66kwh per day :eek:, a daily difference of 42kwh for the heating. That's more like £1.50 a day for heating with an efficient brand new this year combi. Unless my maths is wrong, yours sounds good!

Problem is our heating is timed to kick in when the temp drops to 18deg. I've been overriding this in the evenings but I've come home from work and found that my carbon-fiends have had it on since coming home from school/college because 'it was sooooooo cold'.

Cardew

hotcookie101 wrote: »

Thanks, the meter is m3, today it reads 3 units more than yesterday :eek: :eek: :eek:
Is it just me or does that seem ridiculous for hotwater and about 3 hours of heating?

3 units are around £1.

That seems very good to me for HW and 3 hours heating.

hotcookie101

thanks, I was obviously getting a little confused, £1 a day is £30 a month and lots less than we pay so thats ok. Am sure as it gets colder we will be using more.
Thanks for putting my mind at ease