High gas usage for boiler.

[Shower Engineer]

Any idea what the valve I have arrowed, which looks as though it could be partially tured on, is for?

Just curious....

 

[stevedurban]

Any idea what the valve I have arrowed, which looks as though it could be partially tured on, is for?

View attachment 72874

Just curious....

Sure.it’s to drain the system apparently? Runs off outside?

 

[stevedurban]

That's why I posted this again, its pretty obvious that DHW usage couldn't account for the difference and as I said IF CH can reasonably be ruled out then ???. If one assumed DHW @ 200 litres/day at 60C = 12kwh so 31kwh unaccounted for. I still have a suspicion that the boiler was enabled and firing on its own stat which wouldn't take long to dissipate that 31kwh especially if that ABV was/is passing.

Just to add to the confirmation - here is yesterdays usage.

We were all out around 9am - so the heating was disabled - however the hot water still heated 11-1.

So this shows that when the heating isn’t on - there is 0 gas usage.

 

[John.g]

That seems OK, elect use of 14.11Kwh & gas usage, (5.61x11.33), 63Kwh. I used 82kwh yesterday for CH+DHW. So everything seems fine? and the big problem was (last) summer usage?? You will just have to keep monitoring usage IMO, you have a excellent reporting system, just use gas meter to verify same.
Your bill below, for last summer gives 11.33kwh/M3 so used that, above.

Last summer you used a average of 43.36Kwh/day, for 29 days, apparently for DHW only, that equates to 775 LPD of hot water at 60C or 1328 LPD at 40C, enough to wash a small army?.

 

[stevedurban]

That seems OK, elect use of 14.11Kwh & gas usage, (5.61x11.33), 63Kwh. I used 82kwh yesterday for CH+DHW. So everything seems fine? and the big problem was (last) summer usage?? You will just have to keep monitoring usage IMO, you have a excellent reporting system, just use gas meter to verify same.
Your bill below, for last summer gives 11.33kwh/M3 so used that, above.

Last summer you used a average of 43.36Kwh/day, for 29 days, apparently for DHW only, that equates to 775 LPD of hot water at 60C or 1328 LPD at 40C, enough to wash a small army?.


View attachment 72985

Thanks John. Yes yesterday was ok when the heating was not on

But the day before was this — which I think shows the boiler was almost flat out the whole day pretty much

And this was how it heated the house

 

[John.g]

Heating was not on yesterday, wasn't on the ball there as I thought you went out at 9PM, so you used apparently 63Kwh on DHW, assuming mains at 6C, = 1,003 litres of water at 60C. The DHW heating was enabled from 11 to 1, 2 hours?? so the coil had to be inputting 31.5kwh/hr or a 31.5kw coil, no way. If you assume say 10kwh max was used for DHY heating then, 63-10, 53Kwh unaccounted for, if you take yesterdays usage, of 15.68M3, 178Kwh and subtract 53Kwh you end up with 125Kwh which then isn't outrageous or if no HW heating then consumption, 178-63, 115Kwh, normal enough for your sized house + DHW needs??.

IF no body pinching gas and IF no meter problems then it goes back to the boiler firing, you were averaging ~ 0.3M3/hr, 3.4kw which can easily be dissipated in the piping with all zone valves closed.
I thought you said you were going to run on the cylinder immersion for a few days with the heating coil didabled?. If/when you next go out then monitor the energy usage.

 

[stevedurban]

Heating was not on yesterday, wasn't on the ball there as I thought you went out at 9PM, so you used apparently 63Kwh on DHW, assuming mains at 6C, = 1,003 litres of water at 60C. The DHW heating was enabled from 11 to 1, 2 hours?? so the coil had to be inputting 31.5kwh/hr or a 31.5kw coil, no way. If you assume say 10kwh max was used for DHY heating then, 63-10, 53Kwh unaccounted for, if you take yesterdays usage, of 15.68M3, 178Kwh and subtract 53Kwh you end up with 125Kwh which then isn't outrageous of if no HW heating then consumption, 178-63, 115Kwh, normal enough for your sized house + DHW needs??.

IF no body pinching gas and IF no meter problems then it goes back to the boiler firing, you were averaging ~ 0.3M3/hr, 3.4kw which you easily be dissipated in the piping with all zone valves closed.
I thought you said you were going to run on the cylinder immersion for a few days with the heating coil didabled?. If/when you next go out then monitor the energy usage.

View attachment 72992

Correct me if I’m wrong - but yesterdays usage pretty much shows how much gas the boiler uses to fire up for the HW only (we can see that between 11-1) which looks like

.62m3 from 11-11.30
.34m3 from 11.30-12
.05m3 from 12-12.30
0 from 12.30 to 1 (I’m presuming the water was at temperature and didn’t need heating)

So on the basis that that usage above is right - I would say the only logical change that happens the rest of the day when we are in is that the room stat is calling for heat - which the boiler is trying to fulfil.

Either the house never gets to the temperature because
1) The house just can’t do it due to insualtion issues?
2) the boiler isnt getting hot enough water around? Pump issue? Temperature of the water?

 

[John.g]

Yes, didn,t realize heating was on earlier and the cylinder consumption of ~ 11.5kwh seems spot on to heat ~ 200 litres of water. So yesterdays CH consumption was ~ 178-11.5, 167Kwh, suppose seems a bit on the high side but you are heating a lot of house for long periods each day. You were averaging ~ 8 to 10 kw boiler output.

 

[stevedurban]

Yes, didn,t realize heating was on earlier and the cylinder consumption of ~ 11.5kwh seems spot on to heat ~ 200 litres of water. So yesterdays CH consumption was ~ 178-11.5, 167Kwh, suppose seems a bit on the high side but you are heating a lot of house for long periods each day. You were averaging ~ 8 to 10 kw boiler output.

Yes, didn,t realize heating was on earlier and the cylinder consumption of ~ 11.5kwh seems spot on to heat ~ 200 litres of water. So yesterdays CH consumption was ~ 178-11.5, 167Kwh, suppose seems a bit on the high side but you are heating a lot of house for long periods each day. You were averaging ~ 8 to 10 kw boiler output.

Ok - if that’s in the realms of possibility I guess I can accept that.

The only thing in the back of my mind is that my usage for 7 years was static with an average of 8-10000 a year - and now it’s 60000…. Just strange!

Apart from an Epc - are there any tests I can have that can pinpoint how to increase the thermal effficiency of the house?

 

[John.g]

Even if you averaged 160Kwh/day for the whole heating season of ~ 150days + 11Kwh/day DHW, 365 days/year, then your usage at say 28,000Kwh/year is a long long way from 60,000Kwh/year. although still way higher than your former usage of 10,000Kwh/year.
Don't know anything about increasing the thermal efficiency.