This is getting crazy! Why would he want to install an instantaneous electric shower, with the necessary hefty cabling, when he already has a stored water shower? And still keep the cylinder full of hot water? For economy, as JohnD said, use E7 overnight, and if it's used up in the day, which is unlikely unless he uses a lot of hot water, top up at normal rate. The cost won't break most people's bank, and the OP didn't suggest economy was his main motive, he just wants to rearrange his bathroom.
How to change immersion heater wiring
- Thread starter losferwords
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Energy is getting more expensive and most people should be considering how to reduce their costs.
Economy 7 does still give a significant advantage and I cannot understand anyone who wants to stop using it when it is already installed and set up.
Anyone without gas living in the countryside should have already installed solar panels to generate their own electricity. That can be used to heat water to be stored for use overnight.
Solar thermal are rather more efficient but less popular for installations as they are rather more complicated.
Economy 7 does still give a significant advantage and I cannot understand anyone who wants to stop using it when it is already installed and set up.
Anyone without gas living in the countryside should have already installed solar panels to generate their own electricity. That can be used to heat water to be stored for use overnight.
Solar thermal are rather more efficient but less popular for installations as they are rather more complicated.
Quite simply - The OP is asking how to run his immersion heater 24/7, just to provide all the hot water her needs. An electric shower will relieve him of the need for him to have all that water stored on standby, wasting heat and power. An electric shower is always ready for instant use and consumes no power when it is not being actually used.
I am well aware the OP never suggested cost, but leaving it on 24/7 he soon will be concerned about it.
A typical shower of 4 minutes, though I am usually in and out in less than that, costs around 9.5Kw x 13p 4 /60 = 8.22p - though a decent spec. shower will modulate its power to less than that. It delivers every Kw of heat you have paid for, out via the shower head, no heat lost at all.
Contrast that with heating up an entire cylinder of hot water costing maybe 58p, if the water has to be heated from cold, though I appreciate a shower would not use the entire contents of the cylinder.
I have a cylinder heated by our gas boiler, even so our cheaper and most used option is the electric shower, rather than a bath. Our cylinder is set to be kept hot throughout the day, though not during the night.
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having read all the posts , no one is pointing out the obvious to you, the off peak or economy 7 immersion element is nearer the bottom of the cylinder, when electricity is at cheap rate this element heats the complete cylinder to whatever its built in thermostat is set to, usually 60 C, the boost button energises the top entry immersion and only heats a small amount of water at the top of the cylinder, first thing to do is check that the O/Heat stat has not tripped on the lower immersion and dont switch that one off, it is a well insulated cylinder , so with a complete cylinder heated you would only need to use the booster occasionally, sounds like for one reason or another only the top entry immersion is actually being used
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it is a dual-element, dual-thermostat heater. I don't know how long the longer element is. Maybe about 27"?
It is mounted in the top, so unless he has a short, squat cylinder it may not be heating very much water.
There is only one cable into it, perhaps it is 3-core or 4-core +E
If for some reason the longer element was not working, then that would mean he would have no hot water at all, without him selecting the boost every day. I don't think the OP is suggesting he is having to do that, rather that he is running out of water from having two daily showers, plus all the other uses of hot water.
Additionally, it might be worth the op checking the temperature settings of both of the thermostats. Most recommend they be set at 60C, but I always used to set our stat a bit hotter, at 70C and took the risk of being scalded, but I would never advise anyone else to do that. The hotter it is, the more calories it stores, the further the hot water goes.
I have a cylinder with a top-mounted immersion.
It is 27" long I think, but the cylinder is 48"
so obviously not a great deal of HW
When the boiler is out of action it gives a very meagre bath.
Luckily very rare.
It is 27" long I think, but the cylinder is 48"
so obviously not a great deal of HW
When the boiler is out of action it gives a very meagre bath.
Luckily very rare.
I have a similar cylinder to the OP’s, pre-lagged, usually heated by gas, with immersion standby. A while ago I made some estimates of usage, which is 100watt long-term average (whether gas or electric), split about 50:50 between heating the water and losses. I only use about 50 litre/day water, so probably less than 20 litre/day hot, but using that, through 50K temperature rise comes close to 50 watt. That’s 2.4 kWh/day total, and at your 13p, that’s less than 35p/day, which I don’t think will hurt most people.
As it happens, my electric price was same on and off peak (though still a good dual-fuel deal) but they were one of the firms that’s just gone bust. I assume the OP is getting E7 cheaper, worth him checking his tariff, if he hasn't already.
I’m sure an electric shower is OK, but not many people would install one and take out a stored water shower, to save money. I guess it would take years to break even.
Do you use an immersion heater, not gas?
No, like you I have one on standby, but always use gas for HW. 20L per day of hot, at a guess, is around what we use normal chores - bath days probably much more.
The OP claims to be a qualified electrician, so no great cost for him to install an electric shower.
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