Cost of keeping immersion heated hot water tank on.

[Mick.]

Hi all,

I live in a Housing association ground floor flat that is all electric.

It has a hot water tank with two immersion heaters in, one is for night rate use and one for boosting at day rate.

I am a man living alone, they have just installed an electric over bath shower.

Now that I am no longer using the hot water for baths, is it worth me keeping the night rate heater going for what water I use for washing up etc.

Would it be cheaper just to boil the kettle?

I hoped they would have removed the tank system and put an instant boiler.

We have night storage heaters.

Any thought please?

Mick.

[george [dicegeorge]]

Yes, specially if like me you do washing up once a week!

The immersion heater is losing heat through the cyclinder walls and all the hot copper pipes and any leaky hot taps.

But in the winter all this 'lost heat' would heat your rooms up.

[g]

[george [dicegeorge]]

are the night storage heaters on a cheaper cost of electrickery? [g]

[Mick.]

Hi, yes they are only charged up at night, on the night rate. They are not too bad when you get used to adjusting the input for the next day, say if a coler spell is coming! Mick.

[Phil L]

Turn both immersion heaters off - you are paying to heat 10 gallons of water and you probably only use a gallon each time you wash the dishes. Most clothes washing machines take in cold water and heat it up anyway, so if I were you I would just boil the kettle and do your dishes every other day - I can't see the point of washing 1 or 2 plates, a saucepan and 2 or 3 pieces of cuttlery every day when twice that amount can be washed efficiently with one kettle of hot water.

This is what I do, but I leave the first day's dishes soaking in cold water - this removes a lot of what sticks, gravy, sauces etc which can be a PITA if they are allowed to set hard.

For handwashing you can manage with cold water (lets face it, you've usually finished washing hands by the time the hot gets through anyway!) or just buy those pump action alcohol hand sanitizers.

[Mick.]

Thank you Phil, Yes my washing machine is a cold fill one. Both immersion heaters now turned off,! Mick.

[Dave Liquorice]

Yep, you are only heating what you need.

In the grand scheme of things I don't think you'd notice, space heating takes so much heat. I do know that when the timer switch bust on my gas heating/hotwater system and I went to "on demand" hot water system (still via the cylinder) instead of the timer heating the water morning and night, there was a noticeable drop in the gas bill.

[js.b1]

The problem with not using the hot water at all is the water in the CW tank may stagnate. The problem with not heating the hot water tank is the water may stagnate.

CW tanks were once sized for baths, 500L not being uncommon, but in a world with electric showers, cold-fill washing machines, dishwashers, the CW supplying the HW tank does not change very often. I suspect this is why some plumbers say it can be a good idea to feed the toilet cistern off the CW tank because it can be quieter (torbeck valve not withstanding) and ensures the water changes per week are sufficiently high to avoid water stagnating.

Some NHS nurses are utterly oblivious to how domestic HW can be non- potable whereas unvented high pressure HW systems are more likely to be (no idea if you are allowed to use them as such). Hotel HW systems rely on a continuous circuit of water so it does not stagnate nor have a long draw time before hot water arrives at some distant tap.

[george [dicegeorge]]

js.b1, what is an OW tank?

Legionnaires disease brews when the hot tank isnt hot enough, am I risking this by only turning ont he immersion for baths?

And washing hands in cold water isnt as good as hot, is it.

[g]

[Phil L]

He mentioned a CW (cold water) tank and a HW (hot water) tank

[fred]

In article , Mick. writes

Bear in mind that you are not heating a whole tank from nothing every day, you have losses from the amount of hot water that you use (including filling the pipes to the tap with hot water every time you open the tap) and losses from having a tank of hot water sitting there all day/night and it leaking through the insulation (I hope there is some), that is standing losses and you only have to replace those 2 sources of loss. I have a large cylinder here and it quotes a standing loss of 3.2kWhr per 24 hours which is heated on off peak would cost about 15p.

Personally, I would prefer to pay that 15p per day for the convenience of having hot water on tap 24/7 but once it's there you'll probably use more of it so the costs will be higher.

Some Economy 7 hot water systems allow you to switch off the bottom element so you only have hot water at the top of the cylinder, that might be another option for you.

[george [dicegeorge]]

of course, sorry, the font on this computer made me read O W not C W I wi8ll now try to adjust font or character spacing [g]

[Fred]

Sorry to hijack the thread but on that point, may I ask: a plumber trying to sell our village hall a new boiler said that he could not fit a combi boiler because it would take too long for the hot water to reach the taps. He claimed there was some H&S reg. about this. However two other plumbers provided quotes and recommended combis and said nothing about this. Who was right? Is there a reg. requiring hot water to be delivered within so many seconds? TIA

[Mark]

Run the hot tap every now and again then.

And you can still flush the loo if your mains water is cut off.

It's mainly for the latter reason isn't it?