Would you have the hot water on all day?

[LittleBookofCalm]

I have it on a timer, same as the heating
however if you want a shower or bath in the middle of the day in my house, you need to make sure there is hot water.

do others do the same?
this is a money saver in my eyes

I'm pretty sure I can't control my hot water. It's either on or off. It's the same boiler as for the heating, but that the timer is just for the heating.

The shower is separate and electric. I switch the hot water on for that just when I want a shower and it's hot in a couple of minutes.

I love my combi boiler - which provides plenty of hot water for several taps running at the same time, and keeps the house toasty.

However I do miss having a hot press.

I'm one of the young ones who had no idea this was even a thing haha.

I don't have a combi boiler but I have hot water all day despite the boiler only heating the water for an hour twice each day. That's because I have a large capacity, well insulated hot water tank.

A combi is so much better with instant hot water.

That makes no sense. Assuming the boilers are in the same location relative to the user, the system that only heats the water when you turn the tap on cannot possibly get hot water to you faster than the system that has preheated it even before you turn the tap on. The best it can do is be just as good.

"Cannot possibly"? Well that's true, as long as you can guarantee that there's always a tank of preheated water available.

We put in our current system about 8 years ago now. After dicussions with the plumber and in view of the fact that the house is quite large, the water pressure in the area is rubbish and we have two ever-growing DDs we decided to go for a stored water system. (We did have combis in our previous two houses but they never worked as well as they should because of the poor water pressure).

Although there is an immersion heater in the tank, we only have that for emergency backup. The tank is well-insulated and is situated in a well-insulated loft, so that any heat loss is to the house, not to outside. We did try running the hot water on timer but found that even though the tank is large it could be drained (by DD1s 40-minute showers!) and so now we leave it switched on constantly. This is partly influenced by the fact that it is fairly rare for there to be no-one in the house all day. The boiler, of course, has a thermostat, and so what happens is that the boiler heats the water and switches off, the insulation keeps the water hot until it is drawn off, then cold water enters the tank and the boiler heats it. It's not quite a combi but is the next best thing - even if DD1 does use all the hot water there's a new tankful in 20 minutes. DW was the youngest in a large family in the country where there was no gas so they had to heat with oil, they only heated one tank a day, and she always got the last, cold, bath.

I haven't looked too closely at the effect on the bills; I suspect intermittent water heating would be slightly cheaper, but in my view the possible saving is too little to justify the inconvenience.

Oh, and our showers aren't electric; they are fed from the (pressurised) tank as low water pressure plus an electric shower, as we found to our cost in previous properties, gives a weak warm dribble.

I suspect intermittent heating is mainly cheaper because people limit their hot water use due to its lack of availability. This has been an issue any time we have been house guests with our 3 DC in a house with no combi in summer. They have only ever known a combi and find planning hot water use beyond comprehension.

people limit their hot water use due to its lack of availability.

Apart from the fact hot water is available, I am not sure it is a bad thing to limit water usage be it hot or cold.

Doesn't this thread just prove that there is more than one solution to providing hot water, depending on the needs of the family, the size and type of property and the availability of mains gas?

As I said above, we don't have mains gas, we have a high output oil boiler and a modern, pressurised hot water system with a large and well insulated hot water tank. The water is heated on a timer (heating doesn't have to be on - separate circuit) and we have got that set to meet all our regular hot water needs and a 10min boost is enough if we have a bigger use than normal.
If the boiler needed replacing, I'd look at the combi option but in the meantime there's never an issue and I'm not living in a 1930s world where I have to give a week's notice if I want a bath despite not having a combi boiler.

We don't have a combi boiler. The system boiler runs the central heating and also heats the hot water, in the hot water cylinder (which is in the airing cupboard.

The heating is on a timer. The hot water is just left on all day, and it only kicks in very occasionally, for a few minutes at a time. It seems pretty efficient to me.

We are on mains gas too. I might have to revise things if I had oil fired heating, but I am relieved that we don't.

Mine heats it as it goes, always hot water and no heating up water that isn't going to be used for ages. I'm sure this must save energy the only downside is if you have a power cut there's no hot water. Fortunately it's quite rare to have a long power cut.

every time your boiler starts up/shuts down, it wastes energy in heating the metal and water in the boiler and connecting pipes, which then leaks away into the air. In winter this doesn't matter much, because the escaping heat warms the spiders and mice living in your kitchen ceiling, and the birds nesting above your flue, but in summer it is a total waste.

If you have a modern or properly insulated cylinder, it will stay hot until you used it all, or a couple of days or so. A modern boiler will heat a modern cylinder in less than an hour, and once it reaches temperature, the thermostat will turn off the boiler. So the most economical method if you have a cylinder is to time the HW to start about half an hour before you get up in the morning, and about half an hour before your usual bathtime. If you set it to run for an hour or so, it will top itself up after each bath or shower, ready for the next one, at times of peak use. Even if you left it turned on and went out for the day, it would not keep using gas, because the cylinder is already hot so it will not fire up the boiler.

Unless you have a badly sized, very small cylinder, or are very profligate with your taps, you will not use all up the HW just pottering about. They usually hold between 100 and 300 litres of hot water. So there is no need to have the boiler start up every time you wash a teacup, that will be uneconomical on gas.

It's because combi boilers start up and close down every time you turn on a hot tap, that they cost more to run. You will notice it more in summer when the extra load of CH does not hide it.

BTW, insulate the pipes around your boiler and cylinder. It's very easy and cheap.

A lot of houses can't have combi boilers, I can't because of its age and that there isn't sufficient ventilation, which my current non-combi boiler doesn't need.

Our tank is new and brilliant - it's not insulated with polystyrene like they were back in the days of my early childhood (I'm 30).

Everything in my flat is elec. No gelas whatsoever. We have water heater on all day on eco so we can wash dishes and wash hands ect when we like. Does t cost much, with heating on low and use of electrical we pay roughly £50 a month on our elected key metre

Ours in on a timer to come on twice a day. It is on in the morning from 06.30 - 08.30. I often go to the gym in the morning and come home and have a shower at about 11.00/11.30. The power shower runs off the main tank - I have always had hot water for a long shower.

All household appliances run off cold fill so no need for the hot water during the day except to wash a few bits by hand or mop the floor - again there has always been hot water available for that. Can't see a need to have it on all day.

It comes on again at 16.30 for a couple of hours - DH usually comes in at 19.00 and has a shower then if he's been to the gym.

" it's not insulated with polystyrene like they were back in the days of my early childhood"

is it white?

actually it is insulated with foam, but there is a double metal casing, and the insulation is between the case and the cylinder.

That makes no sense. Assuming the boilers are in the same location relative to the user, the system that only heats the water when you turn the tap on cannot possibly get hot water to you faster than the system that has preheated it even before you turn the tap on. The best it can do is be just as good. Depends on he location of the user too and of the hot water tank. If your boiler is in the kitchen and your hot water tank in the airing cupboard in the bathroom, then a combi boiler will get hot water more quickly to the kitchen tap than the hot water tank can; conversely, your combi boiler in the kitchen isn't going to beat the hot water tank for the bath.

A small house with a combi boiler in the kitchen and the bathroom directly above is going to do very well with a combi boiler. A larger house with an ensuite bathroom and a downstairs toilet on the other may do better with a hot water tank,side of the house. Pipe runs will come into play as well - can you get away with shorter pipe runs if you have a well placed hot water tank?

Sorry to hijack your thread slightly but we have just moves into a house with oil central heating etc. We also have an imersion tank. This is all new to me as have always had a combi boiler - not having hot water on demand will be a shock to me.

So really interested to see if anyone has oil central heating/water finds it lasts longer putting it on twice a day or leaving it on low all day.

I wouldn’t leave it on low all day with oil central heating, it will drink the oil like Oliver Reed at last orders.

Is everything well insulated? I’m assuming your rural.

I’m in NI and I don’t think combi boilers are very popular here. I’ve never had one in 13 years of new builds. All 4 houses have been oil fired central heating with a control panel in the kitchen for the heating and water. Also all houses had an immersion “dear fucking bastard” heater which take about an hour to heat enough water not to shiver in the shower.

Are combi boilers gas? Lots of areas don’t have mains gas here. My town doesn’t.

My heating is on constant but the water (same system) is on a timer. An hour in the morning and and hour in the evening. It’s enough for us although we have a dishwasher but both showers are mains.

Is really miss my hotpress if I had to get rid of the tank. It dries my clothes over night with the heat from the tank and a dehumidifier. Takes up a load of space though.

In winter this doesn't matter much, because the escaping heat warms the spiders and mice living in your kitchen ceiling, and the birds nesting above your flue

Oil heating doesn't work any differently in that regard, it's just a different fuel source. We have ours timed like PJ suggests, it comes on 30 minutes before I get up and goes off about 30 minutes after the last shower. We have it on for about 30 minutes early evening for washing up. There's always enough hot water when we need it except occasionally at the weekends when a teenager decides to have a long shower at midday. Our timer doesn't have a 7 day function so I'm attempting to train them to stick it on again when they leave the shower

Well that's true, as long as you can guarantee that there's always a tank of preheated water available.

In theory at least it should be be possible to have a system boiler preheat water as fast as a combi heats it, so the hot water tank would never run out in any scenario that a combi would cope with.