Immersion Water Heaters Advice

Gremlin

Gremlin

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Since moving my water is heated by an immersion heater on economy 7, the water tank is one of those encased in hard insulation stuff that means the airing cupboard is barely warm.
My washing machine only has a cold water feed, heats the water it needs, and I have a power shower that heats water so no hot water needed there either
Basically I only use the hot water for washing up etc and my morning ablutions
Question is........................................
is it more economical to leave it on all the time so it only tops up the hot water or should I turn it off and only use every few days when the water is cool :shrug:
 
My mechanical engineer work colleague said to me a little while back that its more economical to have it on all the time than have it cool down and heat back up to full temp.

He can be a bit of a dipstick at times though so I'd double check this.
 
I'd have said it would be most economical to put it on for a fixed short time each day. This way it isn't on all the time nor is it having to heat up loads more water at once.

I'd personally look into an instant hot water system rather than a tanked one if you don't use much. They'll be much more efficient as they'll just heat exactly the amount of water you want when you want it.

Some in depth theorising here: http://www.thenakedscientists.com/forum/index.php?topic=25909.0
 
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If its on Economy 7 then it'll only be heated at night on the cheaper electric tariff, often the timer has a boost button but this heats a 2nd immersion that's half way up the cylinder, if it's on economy 7 I'd leave it on the timer for that and not turn it off.
 
im on economy 7 too and with the same set up with shower and that, i find it better to leave it off and then just flick the switch when you need it but only leave it on for a little while (enough to fill 1 or 2 sinks of hot water) just speaking from experience hope it helps
 
But if you're on economy 7 you have to switch it on after 11 and stay up till 12 to turn it off etc as it only supplies power to the immersion at night time low tarrif for 7 hours, hence the 7
 
I have the same useage as the OP, we leave the Economy 7 switch in the off position and just turn the boost switch (2nd element) on for an hour when the alarm goes off in the morning. This heats enough water in the top of the tank for morning ablutions and after dinner wash-up.

If it was out own house, I'd fit a timer to the boost switch but its a temporary rental so we can make do.
 
We have ours on 24 7, both elements, no timer, they are thermostatically controlled do once tank is up to temp the booster element clicks on very couple of hours to put water back up to temp. This is in a house of 5 with 1 teenager and another not far behind.
 
Just a bit of a heads up to avoid anyone having a bit of a disaster...
Immersion heaters have a thermostat in them that cuts the supply to the heater element when the pre set (by manual adjustment on the thermostat) temperature has been reached, as the water cools or is used the thermostat calls for more heat and so on, when the thermostat fails 2 things happen, the first being complete failure and no water being heater, the 2nd, and where disaster occurs is when the thermostat fails to cut the electric supply to the element and the water continues to heat, the water then will boil, as it boils it blows boiling water up the expansion pipe and into the tank in the loft, if this tank is plastic it will then distort the tank and water will gush down through the propery, I've seen this on a fair few occasions. This will not happen on a unvented cylinder but will cause water to blow outside via the temperature relief valve.
All new immersion heaters now must have a thermal cut out that has to be manually re-set to avoid problems with failing thermostats.
 
Martyn D said:
But if you're on economy 7 you have to switch it on after 11 and stay up till 12 to turn it off etc as it only supplies power to the immersion at night time low tarrif for 7 hours, hence the 7
Click to expand...


sorry :thinking:i meant the booster one just long enough for your daily needs. i hate economy 7 worst system ever imho i wish i could install a nice central heating system and i would be warm like a normall person lol(y)
 
Same setup as op. I'm up and about most days at 5am, is when I switch the heater on manually then switch off at 7am water is more than hot enough for two of us, I even turned down the heater stat as don't find the need for scalding water out of the tap.

Must say I never thought of a timer, will investigate that option.
 
Thanks all, something to think about
In my old place I left the immersion on all summer and in the winter water was heated by the rayburn, and backed up with the immersion as baths etc could deplete the hot water
At the moment I do leave the economy 7 switch on at all times, might be worth turning it off and overriding it with the anytime one to see what happens, not sue how I can check the usage though :shrug:
 
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