Immersion water heater

[JakeCross96]

Hello all,

I have recently moved into a new property, which has an electric immersion water heater. We were left no instructions on how to use it, and the landlord only seems to be guessing on what switch does what!

There is a switch that says ‘Water heater’ in the kitchen, which lights up when you press it on. This controls another switch that says ‘Water heater’ by the water tank, the switch stays off but the light turns on. There is another switch below it the also says ‘Water heater’. I think this was on when we moved in, and you can switch its light off and on by flicking the switch itself, off and on.

So far, with both switches on, we had hot water a couple of hours after switching it on. The landlord said something about overnight and boost, but then to leave the top switch (controlled in the kitchen), on all the time. From it heating the water in the day rapidly yesterday, surely this means the water will be continually heated and be very expensive. I thought one switch would be the overnight setting so we would hot water, heated by cheaper off-peak electricity, in the morning.

Any help would be greatly appreciated!

Thanks,

Jake

 

[fixitflav]

Assuming you get cheaper off-peak electric, worth using it overnight. If you haven't worked out what the various switches do you could leave everything off all day and switch it on before going to bed. But if the HW cylinder is well insulated (preferably sprayed-on foam) it's not going to cost a vast amount however you run it.

 

[terryplumb]

Follow the white cables coming from the switches. The cable that goes to the lower element in the cylinder will heat all water above it ,and should be connected to an off peak supply /tariff (if you have one). The higher element only heats water above it .

 

[Harry Bloomfield]

The lower of the two switches, the one which seems to have been opened up, I would guess to be the local isolator for the bottom, off-peak element. The upper one, is the isolator for the boost during the more expensive peak day rate.

I would suggest trying turning both of those switches to on, then see if either lights up during the day, with that kitchen switch turned off. Then turn the kitchen switch to on, when I would expect that top switch to light up.

During the night off-peak period, say 6am, check if the light comes on, on that lower switch.

Repost back, with your findings..

 

[ChrisJP]

The 4-switch unit in your first picture is quite badly cracked and really needs replacing.

 

[dilalio]

First thing is to contact leccie supplier and deduce if you have an on and off peak tariff.

 

[Murdochcat]

I suspect the one in the kitchen is for the "upper" immersion heater - and the upper one by the water tank will be in series with that.

And then the lower one only controls the lower immersion heater

 

[ericmark]

I think @Murdochcat is likely correct, the immersion heater likely has the top thermostat set lower than the bottom thermostat, so for normal use the top one will not switch on, but as @dilalio says step one, is find out if you have a duel tariff. In the main with a twin tariff we use some type of timer there are various makes, but the main idea is to ensure both elements will not be used together, the off peak supply of years ago used a white meter for off peak, but over the years the methods have changed, we did start using teleswitches controlled by radio 4 long wave, but that is due to be switched off, seems the main valve no longer made, so moving over to smart meters, the net result is there are all sorts of of systems.

My immersion is set up only to work when the solar panels are exporting, so I have three tariffs to consider, off peak, peak, and loss of export payment. Plus can be heated from my oil fired boiler, there are losses when heating with oil, with electric the losses are much lower, but to work out what is best, one needs to know what you are paying.