Massive boiler inefficiency (I think)

[mheptonstall]

Hi all,

We've just been burnt badly by a £480 gas bill (only been in house 3 months). Turned TRVs down to 2.5 (so rooms only at 17 degC max), turning boiler off at night and only heating 3 rooms now. But still seem to be using 9 metric units a day!! Which is about £3.50 a day!

Doesn't seem right to me, not sure where to start to try and fix this!!

Any help gratefully appreciated as this is crippling us!!

Cheers,

mark&victoria

 

[petit_pablo]

First things first, what boiler do you have and and other gas burning appliances?

 

[mheptonstall]

House is detached, 1920s (douible brick, no cavity wall) but with double glazing and some loft insulation.

The boiler is a Ravenheat 100ET
We have a 5 burner hob in the kitchen, but seldom used.

I've shut the boiler off and the gas meter doesn't move....did this as a sanity check!

The expansion vessel had lost most of its charge, so we were running the boiler 24hrs a day or it shutoff fully overnight due to lack of pressure. I fixed this by recharging with bike pump a couple of weeks ago. Now though, even having boiler off between 11 and 5am doesn't seem to have made a vast difference in units used.

Hope this helps!

 

[D_Hailsham]

We've just been burnt badly by a £480 gas bill (only been in house 3 months). Turned TRVs down to 2.5 (so rooms only at 17 degC max), turning boiler off at night and only heating 3 rooms now. But still seem to be using 9 metric units a day!! Which is about £3.50 a day!

Doesn't seem right to me, not sure where to start to try and fix this!!

To repeat the well known saying: If it ain't broke don't fix it.

There is nothing wrong. The reason for the high consumption is called Winter.

You have only been in the house for three months and during most of that time it has been very cold, so the boiler has been working flat out to keep an old house warm. The heat loss through solid walls is 30% greater than a cavity wall and nearly five times greater than a filled cavity wall.

My consumption from 2 Dec to date has been just over 12 metric units a day. In the summer it drops to under 2 units a day, for the HW cylinder.

Why don't you go onto a monthly Direct Debit tariff? They are much cheaper and you don't have the shock of a large bill when winter is over.

 

[Agile]

You have said you have started turning off the boiler at night!

Apart from you most people already do that!

That implies yoyu now leave it on all day. So in my opinion thats about normal and I find the annual gas bill for a solid wall detached house is typically £1000-£3000 !

Its no use having only "some" lost insulation. Now that energy is expensive you need at least 150mm and ideally 200-300mm. Anything less and you are throwing your money away.

Tony

 

[Onetap]

We've just been burnt badly by a £480 gas bill (only been in house 3 months).

Yes, winter is ofetn cold, most of your annual gas consumption in 3 months.
Did you check the meter reading when you moved in, or was it read by the suppliers?

 

[mheptonstall]

We left the heating on 24hrs due to the failure of the expansion vessel. It is now off between 10pm and 5am and has shown only about 2 units difference (9 per day instead of 11) as I guess boiler has to work harder to heat the house back up in a morning.

Our previous detached house (1990s build) used 1.2 the gas running the boiler 24hrs and keeping it all at 20°C.

This house takes twice as much gas to keep only 3 rooms at a relatively uncomfortable 16°C.

Loft insulation is on the things to do list! Had I known the bill would be this high it would have been higher on the list. Took three months to move to new gas provider hence no direct debit setup.

Thanks all the replies....I guess we'll be looking at aerogel and kingspan plasterboard to improve things further before next winter