the whole timed vs constant debate

spinningsheep

Hi all. I have always seen the "timed vs constant debates on here and thought I would try a kind of variation on this. We normally have our heating set to come on 6am - 7.45am then 5pm until 9.30pm with the boiler flow temp set to 60 degrees. I wondered if setting the boiler to come on for half hour bursts to "top up the temperature" throughout the night and all day but set to the same amount of time in total would mean gas consumption would stay the same but the house would feel more comfortable, with no drops in temperature and cool spots as I am on holiday from work at the moment. So, the result?

Between 8th oct and 29th we used 1,204kwh costing us approx £60

on the 29th I changed the timer.

from 29th oct to today we used 697kwh costing us approx £33!:eek:

Approx a £10 increase per week if we continued with it, and £40 extra a month!

Moral, WAY more comfortable house, lovely warm even temperature all day long, but a 50% increase in gas bill. Not sustainable for me.

Back to timed morning and evening.

oldskoo1

I think in a nutshell the long the boiler is on, regardless of any setting it will always be more expensive, wether it's on all day and off overnight or on 24/7 it will always be more expensive than on timed.

But don't forget a very very important point, the outside temp from the 1st of november has been drastically colder than october, especially overnight.

I've recently conducted my own experience, timed 2x a day, 3x a day, with and without a programmable thermostat to adjust temp versus on a set lower temp 24 hours a day.

The result is having it on 24/7 uses between 10% and 15% more gas in comparable weather conditions.

50% increase isn't possible i dont think.

Depending on your house, draft proofing and insulation, your house will begin to loose vastly more heat as the outside temperature drops. The higher the internal temperature the quicker it seems to fall. It seems right now, with an outside temp of around 10c the house can maintain a comfortable 17-18c without additional heating, perhaps every 4 hours. At 3c i needs topping up every hour.

i simply can't stand it without having the heat on all day so my compromise is to use a programmable thermostat and have it adjust the temperature throughout the day. I work on the top floor of a 3 storey and it seems to achieve 17.5c - 18c which is comfortable for me with the hall thermostat on 15.5c.

The_Green_Hornet

It is very difficult to do comparisons as no two weeks weather/temperature are the same. For example, I take weekly meter recordings and my gas usage for the first week in November was 50% higher than the last week in October.

The only way I can see that you could make some sense of different timer/thermostat settings would be to ask your neighbour to record his/her usage for two weeks and note the percentage difference between the first and second week.

During the same two week period you should try your "timed" routine in the first week and your "constant" routine in the second and also calculate the difference but this time you can use your neighbour's recordings to take out the temperature/weather variance.

Swipe

There's no reason the tests have to last for 2 weeks. Why not just 2 days? Look at the forecast and find two consecutive days when the daytime and night time temps are going to be similar.

macman

No need for any tests at all, this issue has been done to death on here.
On constantly, will it be more 'comfortable'? Yes. Will it be more expensive? Yes.
2 different questions entirely.

C_Mababejive

There is no debate about it.
The only thing you have to remember is Gas on>meter turns.

Being "comfortable" all day is no longer an option.

rogerblack

C_Mababejive wrote: »

There is no debate about it.
The only thing you have to remember is Gas on>meter turns.

Being "comfortable" all day is no longer an option.

Yes it is!

Cardew

C_Mababejive wrote: »

There is no debate about it.
The only thing you have to remember is Gas on>meter turns.

Being "comfortable" all day is no longer an option.

Let us run a sweepstake on how many times this subject will be raised again this winter.

The usual variation is to ask if CH on 24/7 with thermometer set at, say, 16C, is cheaper than bursts up to, say 24C. - and expect an answer!!!

spinningsheep

Sorry maybe the title is wrong, I know 24/7 obviously isn't cheaper than timed, been done to death as people have said. What I was surprised about was the increase in gas consumption running the boiler for a total of 6 hours in 30 mins sessions as opposed to running it for 2 timed blocks of 3 hrs.

Cardew

spinningsheep wrote: »

Sorry maybe the title is wrong, I know 24/7 obviously isn't cheaper than timed, been done to death as people have said. What I was surprised about was the increase in gas consumption running the boiler for a total of 6 hours in 30 mins sessions as opposed to running it for 2 timed blocks of 3 hrs.

Not really surprising IMO.

In each 30 min session the boiler would be working flat out for most of the session as the house would have cooled.

For much of the later part of 3 hour session the boiler would not be working as the house would be up to temperature.

Take a more extreme example. Have the heating on constant for 72 hours, and compare consumption with the boiler being on for 1 hour sessions once a day for 72 days. Which uses the most gas?

the_heating_engineer

The results may be meaningful for CARDEW but meaningless for anyone else.
1. there is no information on ambient temperatures during the test periods.
2. there is no information on his property uValue.