Gas usage.

schrodie

Since coming home from a weekend away to a frozen hot water pipe and cold water cistern in the loft we've had our CH on continuously since last Monday (20th Dec) albeit very low. As such I've done some calculations as to the usage of gas and was wondering if my results seem reasonable to those who know about these things.

From the times the boiler is ON & OFF I've calculated that on the lowest setting I can achieve on the boiler thermostat the boiler is ON for approx 12 hours (it's on for 3 mins & off for 6 mins) and in this time it uses 6 units of gas at a cost of £5 per day.

Is this a reasonable cost for a 3 bed semi and I have to admit the house is very nice and cosy.

Thanks

molerat

Is your gas meter metric (cu m) or imperial (100's cu ft). If imperial the useage is quite high, 190 kWh, which is £5 per day. If metric that equates to around 67 kWh costing around £2 and is quite low. I use 12 metric units (134 kWh) a day if on 24/7 keeping the house at 18 - 20 deg. What temp is the house at, if that nice and cosy the former useage is quite possible.

schrodie

It's cubic feet as I have to convert to cubic meters for my bills. The bedrooms are 24degC and the lounge 25degC. I'm not too sure if I can turn the boiler thermostat down any further otherwise it'll turn off. I suppose since last Monday the heat has gradually built up and up. 21p per hour isn't too bad to heat the whole house is it??


Shouldn't the cost be the same irrespective of whatever type of meter one has?

red_flump

Christmas Day my thermostat was left on 15C, in 24 hours used 64 kWh, the rest of last week with the mornings and evenings set to 18C (gives 19/20 in the living room) about 115 kWh a day. 2 Bed Victorian mid-terrace.
So at 3.7 p/kWh £4.26 a day (115 kWh)

red

macman

schrodie wrote: »

It's cubic feet as I have to convert to cubic meters for my bills. The bedrooms are 24degC and the lounge 25degC. I'm not too sure if I can turn the boiler thermostat down any further otherwise it'll turn off. I suppose since last Monday the heat has gradually built up and up. 21p per hour isn't too bad to heat the whole house is it??


Shouldn't the cost be the same irrespective of whatever type of meter one has?

With those temps I'm not surprised if your bill is high!
'Average' temps are around 18C in bedrooms and 20C in living areas.
If that is what you call 'CH on low', then I shudder to think what temp you have for 'high'!
Can you not just turn down your TRV's and room stats to a more reasonable temp, and switch it off during the night?-the frost stat should take care of any really lower temps.

schrodie

No I can't turn it down any lower otherwise it'll switch the boiler off. It's an old boiler with a dial thermostat on the front with numbers going from 0 to 7 hence no "frost stat". At the moment it's I would say on 0.4 i.e. just on. I don't have any room thermostats just some thermostatic valves on the rads themselves. I think what's happened is the heat has just built up and up over the days the CH has been on because the house hasn't had a chance to cool down.

Honestly though is £5 per 24 hours considered high when the whole house is lovely and warm? Obviously when the temperatures start to rise above 0deg C then I'll switch it off overnight but we've had pretty low temps here like -14degC and I'm now paranoid about freezing pipes.

Is there any advantage in having a metric meter over an imperial meter?

Thanks

macman

Then turn the TRV's down! if you can't control the system properly, then fit a wireles room stat-the minimal cost of that will probably be saved in a few months.
Frozen pipes are most likely to result from poor lagging or exposed pipe runs, not from having your heating a bit lower.
The meter is irrelevant.

schrodie

macman wrote: »

Then turn the TRV's down! if you can't control the system properly, then fit a wireles room stat-the minimal cost of that will probably be saved in a few months.
Frozen pipes are most likely to result from poor lagging or exposed pipe runs, not from having your heating a bit lower.
The meter is irrelevant.

I was lead to understand that TRVs just cut off the flow of water to the radiator and not turn the boiler off.

I'll investigate the wireless room stat option.

Thanks

ecoelle

Surely a cost of £5 per day is a lot? That means i'ts £150 per month?

Gareth56

Your maths is correct but I think the OP was asking if £5 to heat a house for 24 hours was reasonable. TBH I think it is @ 21p per hour isn't bad at all for a 3 bed semi at the temp it is.

macman

schrodie wrote: »

I was lead to understand that TRVs just cut off the flow of water to the radiator and not turn the boiler off.

I'll investigate the wireless room stat option.

Thanks

If the TRV's are not calling for heat, then the boiler will not be firing. What I can't work out is how your boiler 'stat is heating the house so high if it's set so low-the system is either way over-specified, or the boiler stat is faulty.