Heating on low all day- experiment

[User129867588]

Not sure anyone will find this useful as I know we all have different houses and boilers etc, but I trialled having my heating on all day yesterday, reduced my thermostat to 18 degrees and I spent the same on gas as previous day when the heating was on 18.5 but only on for just over an hour in morning and then for 3 hours in evening! Both days the temp on my thermostat after boiler being off all night was 14.5 degrees 🥶

House is a 2 bed semi, mid 1980’s build. Double glazing that’s over 10 years old and some getting replaced soon. House had insulation added but again that was about 15 years ago.

As seen on pictures the main expense on the gas was when heating first came on and then around tea time. I cooked on my gas hob and then all 3 of us had showers and we use a mixer shower connected to boiler for hot water. I’m with EDF on the variable rate.

I’m doing it again today and if it stays around the same I don’t see any reason for me to work in a cold house in the daytime when it costs the same (or just a tiny bit more) to heat most of the day! I can manage with 18 degrees too and still wear a jumper and extra thermals. Last years 20 degree heat is but a distant memory…….

I don't have a smart meter....these are readings straight from the meter. 4 units of gas and 8/9units of electric. Did the proper conversion maths for the gas to turn it into kW.

Does anyone know what happens if you turn your boiler flow temp right down to say 45?

We have a system boiler not a combi.
I have been doing this for background heat through the day.
Is it bad for the boiler?

I know about the issue with hot water tanks and listeria if the water is below 60 degrees but I remember a heating engineer say that whacking the boiler up to 60 plus every few days would keep on top of that .

Just wonders if anyone did this?

I can’t see how this can be an estimate as you took readings from your actual meter? Sounds like your house is really well insulated!! I hope this continues for you. I’m having my bay windows and master bedroom windows replaced next week and hoping this will make a difference too. We are losing heat in the living room for sure!! They are both double glazed but 17 years old and units have gone on them. I would also like to have my loft inspected too. We had floor boards put in about 18 years ago and looks like there is insulation under the floor boards but nothing in the roof space ? I don’t think the floor insulation is very good! Loft is very cold !

@mimosaaa I wouldn’t risk it without speaking to a professional. When is your next service due? Or can you call whoever serviced it last?

We had similar results. I've shifted from deal to deal for decades now, and it's never been a problem to have the heating on all day. Now we're just using it for an hour or so in the evenings and only for half the radiators. We are using a dehumidifier instead of the tumble dryer, and that helps, but I'm only using that for a couple hours at a time and only while there is washing drying.

I think as temps drop, we may start putting on the heating for an hour in the mornings too. All day heating is a thing of the past for us now.

Tried it yesterday,on all day at 18 and only cost 33p more than the day before when it was on for 6 hours in total at 21 degrees.

Gah, I heated the house to 18 again all day until 8.30pm today, but turned the rads off in the bedrooms during the day. It was £7.50 today 😮

Will try just morning and evening again tomorrow and see if that has also jumped up now it is so much chillier outside.

I can see myself spending lots of time at the office in January and February 😂

@Snnowflake I turn off the radiators in the bedrooms each morning, and close the doors because it seems a bit pointless to heat rooms that no one's using. I just put them back on about 15 minutes before the DC get home. As a lot of people are saying though, it really does depend on the layout of your house, and the level of insulation. Once my house is warm, it stays warm. My last house was a bloody Victorian servants wing, with ceilings that were the height of a giraffe. The only warm place was hugging the aga. Beautiful house, permanent frostbite.

2.5 hours and unable to reach 19.5 degrees? Where is your thermometer?

Why do you need your windows replaced?

@mimosaaa ·

Does anyone know what happens if you turn your boiler flow temp right down to say 45?

We have a system boiler not a combi.
I have been doing this for background heat through the day.
Is it bad for the boiler?

I know about the issue with hot water tanks and listeria if the water is below 60 degrees but I remember a heating engineer say that whacking the boiler up to 60 plus every few days would keep on top of that .

I don't know (helpful!) mimosa but I have a system boiler and hot water cylinder .
I thought the flow temp controlled the heat of water to the rads so that if you turn it down they take longer to reach thermostat temp/heat up ?
My hot water cylinder has a thermostat thing strapped on to it to control the heat in the tank so I thought it could maintain the required temp to combat legionnaires disease regardless of flow temp on boiler .
But no surprise if I'm hopelessly wrong .

Another thing to add is that I think it's a lot more comfortable heat than a burst of high temperature.

I set this regime up at work (timer from 6am Monday then on constant til Friday). Previously we were all freezing til 10am, comfortable for an hour, then steadily too warm, then uncomfortably sweaty. Then steadily too cold again.

Low and constant was much nicer for everyone, and actually made sense of the "wear a jumper" rule. And as manager, it was a great boost to productivity.

Checked after another 24 hours. Same gas usage and slightly less electric as didn't do a load of washing or drying.
I agree @thecatsthecats , it's much more pleasant for everyone and you really feel the

(Posted too soon)
....benefit of putting a blanket over your legs rather than wrapping up in layers!

@Catmatdat the bay is leaking and rotting from the outside , the units have gone too so have condensation on the inside and I feel a draft coming through these windows . They are about 17/18 years old and were never amazing quality

My understanding is that the thermostat on the side of the tank can't override the boiler temperature, so if you set your flow temperature to 50C then that is the highest that the tank will get too. Apparently air source heat pumps which use temperatures of 40-45C get around this by programming in a 60C once a week, which I guess you could do manually for a gas boiler.

Thanks@Reallybadidea - yes that makes sense .Sometimes I wonder where my cognitive abilities went .

Copying this ,in case it helps anyone .
I have a hot water cylinder, what do I do?
If you have a hot water cylinder, you will have either a 'system' boiler or a 'conventional' boiler (aka heat-only or regular boiler) with a 'vented' or 'unvented' hot water cylinder. The HSE state that hot water must be stored in the cylinder at 60°C to kill legionella bacteria (which can be fatal for humans), which means flow temperatures should be 70°C to compensate for heat losses in the transfer of hot water to the cylinder.

In nearly all households the boiler can only supply one temperature, which has to be the higher temperature for hot water safety, i.e. 70degC. It is a sad fact that if you have a hot water cylinder the boiler it will almost NEVER condense! In other words, most boilers that work with a hot cylinder are no where near efficient.

What is the solution? The boiler needs to be set up with separate heating and hot water temperatures, a low efficient temperature for heating and a high safe temperature for hot water. Adapting your boiler so it can supply a lower flow temperature for heating (that you can adjust) requires boiler-specific advice and some minor works to your system. We can provide the correct advice for your boiler via our efficiency audit service.

To be clear, this approach does not suggest you throw out your hot water cylinder in favour of a combi. As we transition to low carbon heating solutions we will need our hot water cylinders once again. Rather the boiler needs to be set up correctly with the cylinder to get the best efficiencies for heating. Go to our latest blog on keeping your gas boiler and making it more efficient.

Is there anything I can do today? You can limit how often your cylinder comes on and make sure it is well insulated. Timing your boiler to once a day before you need it and making the hot water last will reduce how much energy you use eg take short showers. Hot water cylinders lose about 5-7degC over 12 hours so a full cylinder of hot water in the morning should still be hot at the end of the day.

@Catmatdat our thermostat/ control is in the kitchen which is a single storey extension off our victorian cottage.

It usually reads 14 or 15 degrees in the morning and sometimes reaches 17.5 before the heating turns off again. (I have changed the target temperature to 18 now!)
I think I will contact Octopus as it seems to be eating up a lot of units of gas when our usage is not at all excessive.

@Catmatdat the other poster will be correct. My heating is on full blast for 2 hours in the morning and barely reaches 18.5 degrees. Thermostat is in the lounge. I’ve got double glazing and lift insulation but it’s an 1890s terrace.
Basically for some of us to be warm, it will cost a lot more money than for others.

Mine takes about 3 hours to go from 18 to 21 at the moment.

This morning it took 3 hours to
raise the temperature by 1.3 degrees

Actually, it's more like 4 hours, and the thermostat and thermometer in my hall seem to be about a degree higher than the one in my actual living room..

It took 1hr 23 to get from 17.5c to 19.5c this morning.

An experiment in a cold house that take a long time to heat up.
Do you think it would overall save on heating if I boost it for half at hour at 3am, so it can more quickly reach 18.5 in the morning?

Do you think it might reduce the warm up time by more than the half an hour that it’s on for in the night?

We've tried ours for 1 hour and 4 hours on the lowest setting; it doesn't stay warm for long after it goes off, and we can't afford to do it more than twice a week. I'm very worried about the next 2 months.
We've bought insulated clothing and hot water bottles.