Hot water tank, how long do you have your boiler on for?

[PhoneWaiting]

Old house had an on demand boiler which was great. New one has a hot water tank from a gas fired boiler, can’t work out how long to have it on for without risking a day or two of no hot water trying to turn it down.
how long do you have your boiler heating the hot water for/how many times per day and how many people?
Also should I time it for when it’s also on for the heating, is that more effacent if it’s firing anyway or should I have it on separately?

Hour morning and 1 1/2 hours evening

I'm absolutely clueless about these things, embarrassingly so tbh but we recently had a boiler service and the guy from British Gas suggested having our hot water set on a schedule (Hive) of 6.30am-8.30am and then 4.30pm-8.30pm. 2 adults 2 kids. It seems to be doing us fine so far, but interested to see what others do.

I do remember him specifically saying it was more economical to have it come on at the same time as the heating.

An hour in the morning and an hour at night for four adults atm. But sometimes we flick it on a bit earlier/later if everyone is having a shower at once or if we have guests staying.

I only heat mine in the morning, 5.30 - 8.30am, 250L unvented cylinder. We dont use it in the evenings, and if we wanted to Id just flick it on for an extra hour.

Can give you my numbers.

145l unvented cylinder with 25kw boiler. Takes somewhere between 15 and 30 mins to heat to 60 degrees C from about 15 degrees C :

1454200(60-15)=27.4 mega joules (MJ) actual energy required.

24kw boiler in 30 mins will supply 240.53.6=43.2 MJ and in 15 mins 21.6 MJ so the amount of energy required kind of stacks up with the amount the boiler produces in that time.

That 145l provides enough for 2x showers and 2x washing up for me - I turn the boiler on for 30 mins every 2 days. The cylinder is pretty well insulated - even on day 2 the water is still pretty hot.

I don't know whether it is more efficient to turn your heating on at the same time, but I suspect it is, because the boiler will be up to temperature and at least some of the pipework warm. So when I finally get to use my heating (2x per day), the hour in the morning I will make consistent with the time the hot water is programmed for.

The key is of course not to heat more hot water than you actually use don't get a full tank of hot water that is just sitting around all day. The boiler will shut off when it reaches temperature so no waste there. How you would minimise your energy use really depends on the number of people and the pattern of usage.

Remember any heat that comes out of the water cylinder just ends up in the house sooner or later, so it isn't totally wasted.

One hour every morning. Does us for the entire day

We do an hour in the morning and an hour in the evening generally. Probably gets an extra boost a couple of times a week to accommodate for hair washing (2 dds who like long showers!)

Depends on your hot water needs. Mine is on for 1 hour per day but I only need it for a small amount of washing up and the very occasional bath. My shower is electric so heats its own water and my appliances are cold fill so I don't need a huge amount of hot water

Depends on the size of your tank as well. Ours is one for one hour morning and evening for four adults. I’m going to try to reduce it further as far as possible, see how long the water lasts.

The boiler at our old house was set to heat on demand, which is probably a bit expensive. We didn't think about it at all.

We're now between houses, and at the place we're staying we put it on for 1 hour in the morning, and again in the evening on the days the children are having showers/baths. This seems to be plenty for a family of five.

Hour in the morning and an hour and a half in the evening.
We used to have it on for longer, but are gradually reducing the time it is on for to save on energy bills. So far, we've not run out of hot water, and that's with 2 teens who spent an age in the shower.

So, I'd suggest experimenting :)

6.30-9.30 in the morning and 6pm-8pm at night. I have a bath every morning and DH has a shower. Kids have a shower/bath every other evening, ish. I am sure it could be shorter in the morning, we will experiment.

1 hr morning and evening. Electric shower.

We used to have it on for 2 hours morning & evening. DCs are at university/left home so we've recently changed it to just one hour in the morning. Does 2 showers plus washing up - we haven't run out yet. Well need it on more when there are more in the house.

30mins a day for shower but its just me. My hot water tank is old so doesn't keep its heat well so in winter ri literally better shower after its heated the water after otherwise it loses hest quickly.

Mine is on for 2 half hour sessions in the morning: 6-6.30am to accommodate DH's morning ablutions and then again at 7.30-8am ready for mine. Then an hour in the evening 6-7 for DD and the washing up. We rarely run out.

An hour in the evening.
4 of us, but mainly electric showers.
Not done a winter in the house yet. Intending on not having the hot water and heating on the the same time so the bathrooms heat up for longer!

20 minutes in the morning for two people as back up to solar hot water. Was 30 minutes before we had the solar serviced and turned on. Starting to feel cooler recently so may put it back to 30 minutes in October.

We have a 200l hot water tank and have about 30 minutes of (non-powered) showers per day. (Family of 4 - but the adults here are quite quick and the kids are boys with no long hair - but prone to linger).

I have also been experimenting, and I have been heating my hot water to 55 degrees. (Once a week it does an auto heat to 65 degrees for legionella). The water is bloody hot then.

I have cut my boiler "on times" down to 20 minutes once a day and the hot water heats from 35 degrees or so to 55 degrees in that time.

No-one has complained of cold water yet.

I do have a dishwasher and cold feed washing machine, and so not a huge amount of hot water required during the day elsewhere (a few buckets maybe).

So I think people can get away with far less energy than they think! The hardest thing is drying damp towels without a radiator on!

I had a thread for this recently, under property I think.

Only 1 adult and 1 teen, but I changed the boiler timer from one hour morning and again evening, to one hour 6:30 - 7:30am. That meant tank was full of hot water for my morning shower and also had enough for evening washing up and shower or bath for teen. Modern tank so stayed hot all day.

Now I've popped the heating on, I've had to adjust back to am and pm as the heating and hot water aren't separate (I plan to get the timer control changed when I get my Christmas bonus).

Does anyone have a heat pump? I have with an unvented hoy water cylinder.

I only have hot water on for one hour per day but it is using a lot of electricity. Am interested for feedback

1hr a day does the 2 DCs baths and 1 adult going at lightning speed in the shower. 2 hours if all four of us are going to have baths/showers.

We used to have an hour in the morning and an hour in the evening. I’ve just reduced the morning slot by 15 minutes and we haven’t run out of hot water. I might reduce the evening one as well and see how we get on - kids have baths, not morning showers.
Experiment OP, keep reducing it until you run out then you should find roughly how long your household needs it on for.

Hour in the morning and two hours in the evening. Same times as the heating (when that is on, which it obv isn't atm) - 7-8am then 4-6pm.

Electric showers, so it's only for hand/dishwashing (no dishwasher) and baths.

Family of 6, an hour a day is completely fine. We pop it on for an extra hour on a Sunday so two of us can have a bath. Our showers are electric though, so if we were to need to shower 6 people a day with the tank we'd need more than an hour.