Please or to access all these features

Add post

Watch this thread

Save thread

Start a new thread

Flip thread

Hide thread

My feed

Active Unanswered threads

Getting started FAQ's

Unanswered threads Acronyms Talk guidelines

Hide shortcut buttons

Talk

Property/DIY

Join our Property forum for renovation, DIY, and house selling advice.

Flip

Original poster

Hot water timer

22 replies

shrill · 25/09/2019 08:26

Boring but now weather is getting cooler am finding we do not have quite enough hot water for three adults to wash/shower and general cleaning in home. Wondering if it's our system at fault. How long is your on for? (Ours is on 30 minutes every morning and evening)

OP posts:

MarieG10 · 25/09/2019 10:11

I'm amazed you are getting anywhere near enough water for that time. Ours is in for an hour before we wake up and then the duration we are using water, ie up to breakfast. Same in a night so several hours and all day on the weekend

missbattenburg · 25/09/2019 10:21

Ours is on for five hours morning and night

Comefromaway · 25/09/2019 14:44

No wonder you don't have enough hot water!

Ours comes on at 6am which is when dh gets up and goes off at 8am. By that time three of us have showered and I've set the dishwasher and washing machine off.

It comes back on again at 5pm and goes off at 10pm (just after dh has showered).

At the weekend it is on the same amount of time but we often put it on for an extra 2 hours in the morning as we tend to get up and shower late and do extra washing/cleaning etc.

wowfudge · 25/09/2019 15:07

Modern dishwashers and washing machines are cold fill though. You're probably having the hot water on for too long Comefromaway.

There are two if us and the hot water is on for an hour in the mornings. It easily does two showers or a shower and a bath plus cleaning.

MrsMoastyToasty · 25/09/2019 15:09

Do you have a hot water tank or a combination boiler?
We have the latter, so we have hot water on demand.

PigletJohn · 25/09/2019 18:21

I will guess that you have a gas boiler and a hot-water cylinder. Is that right?

What are the dimensions of the cylinder, and what colour is it?

Some photos, including the pipes, cables and controls on and around it, would be helpful. Especially the cylinder thermostat, if there is one.

Have a look at your most recent gas meter readings. how much gas do you use per average day in the summer months? More that half a cubic metre? More than a cubic metre?

You can have a look at your gas bill, but the amount you pay need not bear much relation to the amount of gas you use in any particular quarter.

Original poster

shrill · 25/09/2019 23:43

Really shocked at how long some say their water is on for. In the coldest winter we have had it on for an hour and 20 mins 30 max I'm sure. That's why I'm wondering why it Already needs to be on longer. We do piglet have gas boiler and hit water cylinder. It is very awkward to take pics just now but is nearly as tall as me. When it heats up thwater is very hot as is the norm but I'm trying to be more economical and just surprised that it seems to need to be on longer for nice warm showers etc.

OP posts:

PigletJohn · 26/09/2019 07:31

What colour is it?

whataconundrum · 26/09/2019 08:10

We have a combi boiler and hot water tank in a new build and was advised to keep.it on all day as took more energy to heat it up twice per day

longearedbat · 26/09/2019 08:27

Ours is on for an hour am and an hour pm, that is fine for the two of us, but if we have guests we have to turn it on more, after multiple showers for example.

RainOrSun · 26/09/2019 08:32

An hour in the morning, and hour in the evening.
Occasionally a random hour in the middle of the day if we have been particularly heavy on washing up or something over the weekend (washing machine and dishwasher are cold fill for us)

PigletJohn · 26/09/2019 12:44

I'm going to guess that it is white. So it is an unvented cylinder.

I'm going to guess that it has 250 litres capacity.

So the boiler should be able to heat it in about an hour.

An unvented cylinder can deliver a very powerful shower. I'm going to guess that you have Drencher showers delivering 20 litres per minute.

Three people having five-minute showers would use 300 litres of water.

Some hot, some cold, but (on my guesses) enough to use all the hot water in the cylinder.

This can be addressed by having the boiler timer set go "HW on" at least half an hour before the first shower, staying on throughout the showering period, and for half an hour afterwards.

As regards economy, white cylinders are very well insulated. Once the water has been heated, it stays hot until it is used (or for several days, whichever is the shorter). Leaving the boiler on for two hours will not use twice as much energy as leaving it on for one hour, it just uses whatever is required to bring the water to the temperature on the thermostat.

A white cylinder containing 250 litres of water is more than enough for a day of washing up, so will not need topping up again until shower time comes round again.

(There is however an advantage to turning off the HW outside the bathing and showering period, otherwise the boiler may start up for a few minutes every time you run a hot tap to fill the sink or something. This is uneconomical because every time the boiler starts up it has to heat itself and the pipes, and short runs are wasteful. This is why an hour or two twice a day, leaving the cylinder with sufficient hot water for minor incidentals, is cheaper.)

Comefromaway · 26/09/2019 13:03

This also makes sense for us as Ds’s showers are not 5 mins. I’m usually banging on the wall after 10 mins to tell him to get out of there! And by the time Dd has gone through all her shenanigans of hair products, shaving and goodness knows what she’s usually well over 5 mins too!

TobyHouseMan · 26/09/2019 13:45

Please don't confuse yourself with having the hot water on with having the heating on.

With the hot water it doesn't really matter how long it's on for as once the water is up to temperature the boiler stops heating it. If you left it on 24/7 without using the water then the boiler would only fire up when the hot water dropped in temperature. And this temperature drop would be because of the heat lost from the cylinder. The better insulated your cylinder then the less heat is lost and the boiler has less work to do to keep it up to temperature.

So as long as your cylinder is fairly well insulated then having the boiler come on for longer would not actually cost you much additional money.

I'd recommend you try having it for an hour before you plan to use the water - if this still doesn't work have it come on for an hour before and for the full time you're using it. Any heat left in the tank will mostly still be there for the next period.

Original poster

shrill · 26/09/2019 23:41

All very enlightening. Thank you. I finally reached it it just looks copper but that's the very top. It has a red padded jacket tied round it and is difficult to untie so I don't know if a bit further down it is anything else.

OP posts:

Original poster

shrill · 26/09/2019 23:45

I used to have it on for a lot longer but we always seemed to have very hot water all the time so I've been experimenting to see how much it really does need to be kept on for instead of having it on for what might be far too long and so i thought wasteful. However the replies have been very helpful so again thanks .

OP posts:

PickAChew · 26/09/2019 23:48

Back in the day without a combi boiler , we had 90 minutes morning and evening.

PigletJohn · 27/09/2019 00:58

Ah. Copper and red jacket is very old. This means it will be slower to heat than a modern one, and the insulation is not so good so it will lose heat faster.

Can you photograph it, and the pipes and cables around it, please?

I am particularly interested to know if it has a thermostat strapped round its lower waist, inside the red jacket. There will be an electrical flex going to it and it will look something like one of these

There may also be a pump and a 3-way valve, which will also have flex going to them. The valve will look something like these

photos of both will be useful.

It is possible that your system does not have them. Looking at the pipe layout will give other clues.

The cylinder is probably of diameter 18 inches or 24 inches, and height 36, 42 or 48 inches. It might be standing on a thick wooden platform.. If your home is unusually large it may be bigger. It will be useful to know the size.

longearedbat · 27/09/2019 07:03

I used to live in a very hard water area (we actually had a 'petrifying well' up the road) My copper tank with red jacket (like the op's) began to leak so was replaced. The plumber, who was a big strong chap, had to get a mate to help him carry it downstairs, as it's interior had literally turn to stone. There was virtually no space left for hot water. I couldn't believe the difference when a new tank was fitted.

Original poster

shrill · 01/10/2019 18:24

Oh dear longearedbat sounds like we really should get a new one but new never seems to be as good/long lasting for anything.

pigletjohn it really is kind of you -sorry not posted pics yet I've a bad shoulder and can't get to it to take pictures yet. I noticed it has two white wires coming from under jacket at bottom and while there is a new thermostat at front away from it there seems to be a black circular thing at the top.

The link showing the drayton valve looks similar but ours is dark blue

OP posts:

Original poster

shrill · 01/10/2019 18:27

Been having the timer on for an hour morning and afternoon and we have plenty of hot water again. So I'll play about with it to see if we can manage with 45 minutes until it gets colder out.

OP posts:

janj2301 · 01/10/2019 18:42

Only two of us put water one for an hour if we want a bath.

Flip