Not putting the heating on – how’s it going…?

Still not on here, heck, it about 15 degrees today so it’s basically summer.
Clothes are taking a while to dry inside, but not to the point they smell musty. Current debate is if a dehumidifier is worth the investment to dry clothes.

No, there’s a point where it makes sense to put the heating on. It doesn’t have to be on super hot though. The colder it gets the warmer the same interior temperature feels because it’s reducing the relative humidity.

Re cold fill washing machines and dishwasher – I’d been told that it was more efficient, and it might be in terms of actual energy used, but it rather depends on how you heat your hot water as singletrackmind says. If you have a cheap overnight tariff and you can put your machines on a timer, as we have, then cold fill makes sense. However if you’re heating water with gas it must be much cheaper to use hot water. But if the machine’s only got one fill, then you might need to set up your own mixer to produce 30C water rather than 50C or whatever your HW is.

Getting borderline now in our flat to either start using the Economy7 storage heaters, or using the last ~60mins of night rate electricity with our electric heater with integrated timer.

Re cold fill washing machines and dishwasher – I’d been told that it was more efficient, and it might be in terms of actual energy used, but it rather depends on how you heat your hot water as singletrackmind says. If you have a cheap overnight tariff and you can put your machines on a timer, as we have, then cold fill makes sense. However if you’re heating water with gas it must be much cheaper to use hot water. But if the machine’s only got one fill, then you might need to set up your own mixer to produce 30C water rather than 50C or whatever your HW is.

It’s more to do with pipe volumes.

Machines use tiny amounts of water, about 5l to wash and 5l to rinse.

So all you end up doing is filling the machine with 5l of cold water from the hot pipe, which you have to then heat up electrically, and 5l of hot water going cold in the pipe that you’ve heated up with gas.

+ the boiler having to do a startup/shutdown sequence if it’s direct from the boiler rather than a HW tank.

Machines use tiny amounts of water, about 5l to wash and 5l to rinse.

So all you end up doing is filling the machine with 5l of cold water from the hot pipe, which you have to then heat up electrically, and 5l of hot water going cold in the pipe that you’ve heated up with gas.

Inaccurate on both counts:

I don’t know what diameter pipes you have or how long your pipe runs are but in my case it’s 1.3l of cold before the hot water comes through (I’ve just measured it, how nerdy is that ?). Putting my hand on the washine machine window proves it’s warm to the touch. The rinse is done with cold water obviously.

A modern washing machine typically uses 50l of water per cycle, about 5 times what you claim.

Ok
In the interest of science i am going to do 2 loads of washing
I will weigh the clothes to equal out that discrepancy.
I will switch off all electrical items at home at the plug.
Then i shall record the gas and electricity meter readings.
Do 1 wash with combi boiler fed hot water
Then record gas and electricity readings
Do wash 2 with cold tap water.
Just to prove its half the cost to primary fill with hot.

So after having the heating turned down to 16 in a morning and 18 in the evening, clothes are taking forever to dry to the point I’ve now brought convection heater in from garage and using that with the clothes dryer a timer and cheap rate a night finding a happy medium.
Got last months bill £97.24 the same period last year was £91.73.
It’s cold sometimes but have found that using electric fire in living room is cheaper that using central heating.

Ok
In the interest of science i am going to do 2 loads of washing
I will weigh the clothes to equal out that discrepancy.
I will switch off all electrical items at home at the plug.
Then i shall record the gas and electricity meter readings.
Do 1 wash with combi boiler fed hot water
Then record gas and electricity readings
Do wash 2 with cold tap water.
Just to prove its half the cost to primary fill with hot.

Glad I’ve stirred up some debate, but in actual fact I really don’t care all that much.

I’ve installed a lot of washing machines and dishwashers and ALL of them say it’s important to have cold fill only. I’m not sure they’re saying that just to cost the owners a few extra pence on a wash every time.

Cracked on a cold day but it’s off again (*will be on soon tho as grandchildren coming)

Experimenting – gas fire in living room vs central heating (*thermostat down 2’). Cold bedroom etc fine, cooker generally warms kitchen, but the mrs isn’t liking a cold bathroom post shower (or the towels not drying properly).

Working smart meter would be handy, but we have a dumb smart one from a previous supplier.

Todays elderly person top tip.
Flanellete sheets, takes away the getting into bed cold shock, deffo winner.

Got last months bill £97.24 the same period last year was £91.73.

That’s not bad going, given the price rises.

I’ve installed a lot of washing machines and dishwashers and ALL of them say it’s important to have cold fill only.

They do, and I’m not sure why. Once (a long time ago) I connected my jetwasher to the hot tap to see if it cleaned my bike super-effectively. It didn’t, and it overheated the jetwasher really quickly. I don’t expect that a washing machine relies on water for cooling in the same way but it might cause some problem or other. Not least because in my house, every wash would be a hot wash at 50C as well as the rinsing, whereas you really only need to wash at 20c or at most 30C and you can cold rinse. Most of my clothes specify 30C on the label for a start.

Now that I’ve modified our heating it behaves and responds differently. I am going to put the central thermostat higher than it used to be to keep the rest of the house warm.

assuming the warm water needed is 20l and the cool water is 30l, ambient temp of water is 10C and the hot water is needed at 40C (and ignoring any inefficiencies in heating water in pipework etc)..

20l of water heated up by electricity is 24p, per wash

50l of water heated up by gas is 17.4p, per wash

so its definitely cheaper to use gas, if you have a 40C feed to the wash, but by such a meaningless amount that I don’t think anyone will really care – how many washes per person are needed a year? 100? to in total this might save you £6.50 per person per year.. I guess you’d probably want it downmixed to 30C (from whatever you normally have your tap running at – 50C?) to be able to use 30C washes.

We’ve had to shut the bedroom window at night now as Pembrokeshire has been very windy for a couple of weeks now. I’m wearing jeans and socks watching telly at night but don’t really need a jumper yet. Daytime temps outside are still in the teens and not much colder at night.
No heating yet but the heated airer is doing the clothes overnight.

@5lab but your rinsing is also done with hot water rather than cold if you have hot fill.

Re wind, our house is definitely colder when it’s windy. We’ve been trying to trace draughts but it’s not obvious apart from the fact that some of the windows don’t shut properly, but we can temporarily fix that with tape. I’m looking at the walls surrounding the window frames next. I could do with a thermal imaging camera.

@molgrips – thats why I calculated gas heating 50l instead of 20l. There might be other advantages of rinsing with cold water (is that what you’re eluding to?) – I’m not a washing expert 🙂

Todays elderly person top tip.
Flanellete sheets, takes away the getting into bed cold shock, deffo winner.

got an electric blanket for the first time the other day! Only 100W so costs like 3p to stick it on for an hour before bed. Really good!

Yeah washing machines don’t heat the water for rinses, and this is the majority of the water usage.

Yeah washing machines don’t heat the water for rinses, and this is the majority of the water usage

Why do you believe they fill with hot for rinsing? Mine doesn’t.

I love my electric blanket. Doesn’t even need to be on for an hour – switch it on when you go to brush your teeth, then come back a few mins later. Like getting into a warm bath! Aaaaahhh

Why do you believe they fill with hot for rinsing?

Singletrackmind’s does because he’s plumbed the only inlet to his hot water, hence the discussion.

we went with an electric blanket on a smart plug -> alexa a few years ago. Asking the voice servant to warm your bed 10 mins before you wander upstairs is a modern marvel 🙂

You just need a couple of valves to flip to fill hot and rinse cold. Even Madame can do it. On the basis of 41 weeks and 3 washes a week at 24p (see above I haven’t doen my own sums) that’s £30 a year the solar thermal saves just in washing clothes.

We’ve been using the dehumidifier after showers but still no heating needed.

because he’s plumbed the only inlet to his hot water

Ah, gotcha, I’d missed that detail. Mine’s an ancient* Zanussi with both a hot and a cold inlet.

*I’ve had it 25 years and bought it secondhand.

Nov 21 bill – Electricity 524 kWh £101  Gas 1724 kWh £65

Nov 22 bill – Electricity 307kWh £115 Gas 783 kWh £89

bills are for Oct usage obv..

Gas 63kwh
Elec 88kwh
October figs obvs.
Still no ch on here as its 15c outside.
Ran it for 10mins to check for air, sludge and wound in a ls valve on a rad thats always red hot. Still working which is nice

Leccy was

October 2020 389kwh (60 quid )

October 2021 224kwh (37 quid)

October 2022 83kwh (26 quid)

The hot water in the washing machines almost exclusively heated by the solar PV – solar thermal next but still won’t be messing around with valves during a wash cycle.

26c outside and 25c in the bloody office cos the air con is crap

deffo not putting the heating on it’s darn near bushfire season 🙂

The subject of hot water supply temp to appliances or to the taps is solved by fitting Thermostatic Mixer Valves.

I have one on the outlet of my cylinder, so the water at the taps is regulated to around 42°c and if you wanted a lower temp to dishwashers you’d just fit another at that appliance.

These TMVs allow you to store high temp water (solar thermal regular gets to 70° in summer) and minimise the amount you use.

I don’t have a problem supplying my dishwasher with 42° water and would be happy to supply my washing machine with 30° for wash and rinse if the hot was free (solar thermal). My understanding of rinsing with warm water is that the clothes come out wrinkled (but that’s not my specialist subject).

TMVs are highly recommended 👍

Electricity

Nov 2022 290kWh £50
Nov 2021 430kWh £63

I can’t tell with gas because we don’t have a smart meter and it’s a mess of estimated readings and late readings by me.

Weelllll…. In Cambs, it’s still shorts but the heating’s been on a couple of times though it’s gone a bit milder again. We got down to max 10°C during the day a few days ago. Y’know, when the roads are perma wet and the house starts to become a cold sink. The heating is set to be available for an hour in the morning and 3 in the evening. Set to 16°C, thermostat in the hall but not calibrated to anything so could be any random temp.

We’re not messing with the dish or clothes washers. The latter is mostly used at 40° or 30° and I really CBA dicking around for 3 washes a week.

Ran it for 10mins

I have turned my gas Ch on for 15 minutes this morning to make sure nothing is becoming seized.
I have been using a fan heater, far infrared panel heater and a electric blanket for the rest of my grid powered heating needs.

Significantly reduced gas usage last year vs 2020. I think by just reducing the base temps in kitchen and lounge (terraced house). So now you have to actively turn a rad up for the boiler to fire. Also did away with the fancy geo-location thing and now just turn off/on when needed.

We’re not messing with the dish or clothes washers. The latter is mostly used at 40° or 30° and I really CBA dicking around for 3 washes a week.

Our dishwasher is on daily = worth swapping a hose from cold to hot.

I have been using a fan heater, far infrared panel heater and a electric blanket for the rest of my grid powered heating needs.

Gas is still 1/3 the price of SVT electric per unit. Why would you switch to grid electric?

I cracked over the weekend but set it to 19deg in the evenings and for an hour in the morning. It hasnt actually come on in the evenings yet.

Heating on, boiler now broken. That’ll teach me.

Gas is still 1/3 the price of SVT electric per unit. Why would you switch to grid electric?

Presumably because it’s much easier to heat just the room you need with electricity, and 100% of the energy you use goes into that room unlike with gas.

Presumably because it’s much easier to heat just the room you need with electricity, and 100% of the energy you use goes into that room unlike with gas.

There are many schools of thought on this, both personal and peddled by companies and organisations. The only true way to measure the cost is to take your meter readings.

My thoughts are that this single room heating thing isn’t efficient as the rest of the house is lowering it’s thermal mass and needs to be heated at some point. I run my gas heating at a reduced flow temp (currently around 33°C on weather compensation) which I am finding reduces the moisture levels in the house and is very comfortable and efficient.

The only truth is what you pay 🙂

Gas is still 1/3 the price of SVT electric per unit. Why would you switch to grid electric?

not sure they’ve made a gas-fired electric blanket yet 🤔 Also IR heaters are pretty efficient… I have an 800W one for the shed (costs about 27p/hour to run) which warms up whoever it’s pointed at instantly, so could be good to plonk next to you if your watching telly on the sofa for a few hours I guess! Electric fan heaters, not so much. Horrendously inefficient.

I must admit I have no actual idea how much it costs to warm our living room for an evening, say, via gas CH. Although we’re getting a smart meter installed next month which should make things a bit clearer!

Presumably because it’s much easier to heat just the room you need with electricity

unless you have smart TRVs 🤔 Which whilst expensive to install make more & more sense as energy prices go up!

Also IR heaters are pretty efficient… I have an 800W one for the shed (costs about 27p/hour to run)

Or, run your 19kw boiler, which is modulated down to 7kw on weather comp for an hour. Of which it will only be firing for 30mins. (costs 10p/kw x 7kw = 70p/kwh = 35p/HR to heat the whole house).

Read my comment about thermal mass & turning rooms off 👎

The only truth is what you pay 🙂

Or, run your 19kw boiler, which is modulated down to 7kw on weather comp for an hour. Of which it will only be firing for 30mins. (costs 10p/kw x 7kw = 70p/kwh = 35p/HR to heat the whole house).

I see what you’re saying, that trying to heat a single room is like trying to heat an uninsulated house because the heat escaped relatively easily.

I’d still back the idea that it’s cheaper heat 1 room electrically than a whole house on gas.

Especially if you’re using IR heaters or electric blankets. A 70W electric banket obviously makes you feel a lot warmer than a 7kW boiler overnight, and uses 1% of the energy, even if it is 3x more per unit. IR to a lesser extent, especially in poorly insulated or draughty spaces.

Or, run your 19kw boiler, which is modulated down to 7kw on weather comp for an hour. Of which it will only be firing for 30mins. (costs 10p/kw x 7kw = 70p/kwh = 35p/HR to heat the whole house).

hmmm, think our boiler is a bit beefier than that & it doesn’t have weather comp as far as I’m aware (it’s not mentioned in the manual anyway. It’s fairly old) That said, I do use our gas boiler for heating the house – the IR heater is for the shed (like I said 😂). I was just commenting that it’s probably not particularly terrible vs gas costs. 😃

Read my comment about thermal mass & turning rooms off 👎

Smart TRVs don’t necessarily mean that you turn the room off it can (and generally is) just set lower. You can’t actually be suggesting that having the entire house at (say) 20° when you’re literally only using one room is somehow more energy efficient? 🤔

The only truth is what you pay

yeah, difficult to work out tbh although will have a clearer idea once smart meter is fitted! Maybe I’ll run some experiments over a few weeks!