To have the water on constant or not?

moments_of_sanity

I have heard varying arguements for both - I have turned my water temp down today as it was set at 65 degrees so turned it down to 55 degrees but it's on constant.

Some say that it costs more to heat a whole tank up a couple of times a day than it does to keep it running at constant. Has anyone done their own research and if so what were your findings?

Thanks :j

HappyMJ

55 is a bit too cold you are risking bacteria growth. Set it to 65 and set the timer to come on twice a day. It'll cool down a bit but when it hits 65 it'll kill off all the bacteria such as legionella...

rogerblack

moments_of_sanity wrote: »

I have heard varying arguements for both - I have turned my water temp down today as it was set at 65 degrees so turned it down to 55 degrees but it's on constant.

Electricity or gas?
If it's electricity, you'll save a bit - simply as the average difference between the inside and the outside temperature is lower.

If it's gas, the sums are a lot trickier, as it depends on how much the cycle time changes, and your boiler efficiency, and pipe losses.
My tank losses were around 80w average when I measured it - which would be around 120 quid a year now.

One thing you can do - yes your tank is insulated - more is better!
If you get a roll or two of insulation, and wrap the tank up to a rather silly depth, you can halve the loss or more.

In addition, sometimes for small amounts of hot, it can be inefficient to waste the water that sits in the pipe.
Turn the tap on with a bowl under it, and stop it once it gets usably hot.
How much water is this?
If you use this amount, then the efficiency of this water use is 50%.

Is your water heater the sort that has a seperate plug, which plugs into a socket in the attic or wherever it is?
If so - stick an energy meter onto it, and measure!http://cgi.ebay.co.uk/PLUG-ENERGY-SAVING-ELECTRICITY-MONITOR-METER-/200576021559?pt=UK_Gadgets&hash=item2eb3433437

moments_of_sanity

rogerblack wrote: »

Electricity or gas?
If it's electricity, you'll save a bit - simply as the average difference between the inside and the outside temperature is lower.

If it's gas, the sums are a lot trickier, as it depends on how much the cycle time changes, and your boiler efficiency, and pipe losses.
My tank losses were around 80w average when I measured it - which would be around 120 quid a year now.

One thing you can do - yes your tank is insulated - more is better!
If you get a roll or two of insulation, and wrap the tank up to a rather silly depth, you can halve the loss or more.

In addition, sometimes for small amounts of hot, it can be inefficient to waste the water that sits in the pipe.
Turn the tap on with a bowl under it, and stop it once it gets usably hot.
How much water is this?
If you use this amount, then the efficiency of this water use is 50%.

Is your water heater the sort that has a seperate plug, which plugs into a socket in the attic or wherever it is?
If so - stick an energy meter onto it, and measure!http://cgi.ebay.co.uk/PLUG-ENERGY-SAVING-ELECTRICITY-MONITOR-METER-/200576021559?pt=UK_Gadgets&hash=item2eb3433437

I'm pretty sure it's gas run bu the tank itself is only insulated with the foam that is on the tank - is this enough or should I be putting more on it?

I have switched it back up to 65 degrees and timed it for twice a day (hour in the morning and an hour and a half in the evening) so going to see how this works.

I switched the the British Gas capped rate recently and they are going to send me an energy meter so will definately be checking what we are using, although with the hot water it will be difficult as it doesn't have it's own plug.

satchmo1

moments_of_sanity wrote: »

I'm pretty sure it's gas run bu the tank itself is only insulated with the foam that is on the tank - is this enough or should I be putting more on it?

Definitely add loads more insulation. Experiment with how short a period of time you need to heat the water - cut it down even more and if that isn't enough, raise it by small increments until you get the optimum time. When the weather is warm you won't need as long as during the winter months (by which time pennies might not be so tight).

Most of us habitually wash our hands under the hot tap, but how often is the water still cold by the time you've finished?

Is there any hot water left in your kettle each time you brew up? Put the left-over in a flask each time, and use that to wash up.

As you said elsewhere "every little helps"

Hugs, Satchmo x

Mrs_Arcanum

Definitely 65 degrees & twice a day is plenty. If you do not use the hot water much during the day it will use very little energy heating it again. Plus it will stay hot enough for hours in the summer once heated.

x_Kaz_x

We have an ancient gas heated water tank (we've lived here nearly 10 years and it was OLD when we moved in). I turn it on for half an hour in the morning and that lasts us (OH, me and 2 kiddos) all day for dishes, washing etc... We only turn it on for half an hour at night every other day for bathing. It seems to be saving us money on our gas, compared with last year when we kept it on constantly.

dreamdreamer

We don't really use the hot water tank! We turn it on when one of us wants a bath (it heats in about 20 mins) but otherwise we just don't use the hot water. We have a dishwasher and electric showers and we're at work all day anyway. It's gas powered and in the summer when the heating is off our gas bill is about £4 a month (we worked out it costs about 63p to heat our tank for an hour). But we make up for it in the winter! I can't stand being cold.

moocowone

moments_of_sanity wrote: »

Some say that it costs more to heat a whole tank up a couple of times a day than it does to keep it running at constant. Has anyone done their own research and if so what were your findings?

The question is: Which uses more energy?

a) Heating the water for 2 hours or day
b) Heating the water 24 hours a day

Answer: It's obvious, isn't it? (b) uses more way, way, way more energy.

I see what you're saying about "heating it up from cold" but, basically, that's nonsense.

Switch the heater off, you'll save money. It's as simple as that.

exil

It's not quite as clear cut as that, as when the heater is "on" it only kicks in to counter the heat loss through the sides of the hot water tank. However it's still going to be cheaper to have it switched on only when you need it (though it may take some time to heat an entire bath-full).

Best option is a combi-type gas boiler that only heats water "on demand".