gas usage experiment

[honey33]

bearing in mind i live in a very small 2/3 bed terraced house...have full double glazing and maximum loft insulation and gas is only used for hot water and heating using a combi boiler... we had it on timer with the room thermostat at 22 deg 2hrs in morn and 6hrs from teatime and had 1 hot bath.... the gas used 8 units in that time.... so 2 moro we are trying to see how many units it uses on same senario except taking away the timer and having it on constant on 22 deg...... has anyone else done a similar experiment and which senario did you find used less units??

[The-HouseHusband]

Using the boiler on a timer will nearly always result in a lower fuel usage. A better idea would be to use the same timer settings and gradually reduce the room thermostat. 22 degrees is a bit on the warm side if you have full insulation and double glazing.

I run my Combi boiler on a timer from 0600 to 0830 and then again from 1630 until 2100, and temp set at 20 degrees, having it come on in the late afternoon as the air outside starts cooling means it dosnt have to work as hard to maintain a comfortable temp inside.

My house is end of terrace 4 bed with loft and cavity insulation, double glazing and a gas hob. 2 adults and three teenagers in the house and we use around 5 units a day.

[AlBags]

Which is why programmable stats can be pretty useful.

[honey33]

we dont have cavity wall insulation as its solid brick with concrete floor so its pretty cold in our house... do you use shower to get your 5 units? dont understand why we are using 8 units with the boiler set for the same amount of hours as you and we dont have gas cooker

[The-HouseHusband]

We have concrete floors as well, best thing to help there is to invest in quality underlay for your carpets, makes a massive difference, it is false economy going for cheap underlay as it wont last as long and gives poor insulation. use electric shower but at least one out of the five of us has a bath each day. Plus it is only a gas hob with a separate electric oven.

I would hazard a guess that as your thermostat is set higher then that will be the reason for your higher consumption, it is definitely worth your while lowering the thermostat slightly to see how much of a difference it makes.

[honey33]

we have the thickest underlay we could get..... todays experiment is to have the gas on timer for 2hrs in morning and then have it on constant for the rest of the day on 20 deg.. will let you know then how many units that uses.... but yes your probably right about turnibg the thermo down ... it just feels so cold in our house especially where your just sat doing nothing lol.... also when weve been cold at work all day then come home its hard to get warmed up till we have a bath

[bookbinder]

We did an experiment two or three years ago, along the lines that you suggest. From mid-October to mid-April we left the (gas condensing) boiler on for 24 hours per day. At night, the room thermostat was turned down to about 18 C, and the same if we went out during the day. If we were in during the day, the thermostat went up to about 19 or 20 C. This system was cheaper than having the boiler firing up twice a day, and having to heat up a stone-cold house. We live in a 1994 3-bedroom detached bungalow. We are both retired, so we don't go out much.

[honey33]

i will soon be able to see which theory is best and will let you know soon

[KARL]

Switching the boiler off will consume less than switching it on (like starving cuts food bills) as in the stop-start timed routine but you will not have heat. Heating for a short period (only some hours) will not result in a reliable indication of what constant heating costs because you are not heating the whole fabric of the house and all contents to the target temperature. Your result will be heavily dependent on a number of factors including conditions at the start and any weather factors over the period. Only by comparing overa week or more after reaching a stable state (itself taking a week or two to reach) will you have a reasonabley good idea but even then any weather differences over the periods used for comparison of different systems will skew the result. Note that the timed routine test must be done with the house also in a steady state (not pre-warmed by constant heating). For reasonable daily heating then constant heating with only thermostatic control (not timed) will prove cheaper than letting it cool off and then reheat twice or more a day - the effort of reaching steady warm conditions at the start is the most expensive part of that regime and once achieved the cost of maintaining it is more efficient than not. Compare with a car driving from A to B: The initial acceleration to cruising speed uses up a disproportionate amount of fuel, after that the most efficient way of driving is to do so at a steady speeed. Extremes of stop-start events has a very bad effect on consumption but if money is short then rationing of heat may be the only option.

[honey33]

we seem to use 8 units set at 22 degrees and have timer on 2hrs in morn and 4 hrs from tea time and a bath.... and when set at 20 degress it used 6 units and if heating was on low all dayish it used 6units so we are sticking to the 2nd option and using a halogen elctric heat in the living room if we feel a bit nippy