Is my electric immersion water heater wired up correctly?.

[Mark5290]

Moved into a place a couple of years ago and there was no manuals or instructions of what settings and how to use things like storage heaters/water heater etc, the LL just told me what settings he used when living in an identical property.

After getting a few highish electric bills i decided to look into what was supposed to be switched on and what did not need to be on.

My question is about the wiring to the water immersion heater. -

My electric immersion heater is a Santon TP120E, there are 2 hard wired sockets next to it on the wall in the 'airing cupboard', someone has written on the wall above one of the sockets "Top", i think i am right in thinking that this water heater has 2 heater elements, the primary element at the bottom and the 'boost' element at the top, there is also a switch in the kitchen with "H/W Boost" written on it.

Now the socket on the wall that feeds the lower element is live during my cheap rate electric periods, - 01.00 - 06.00, 13.00 - 16.00 and 20.00 - 22.00(economy 10, Heatwise), and will heat the water when it is cold, that's fine i get that.

But the other socket marked "Top" is live all the time, if the water is cool and i switch it on(i have it off at the moment), then i can hear it start to heat the water, this is at times outside of my cheap rate electric periods, so it appears to be using normal daytime electric to heat the water at the top of the tank.

The other strange thing, is that i understood the H/W Boost function, as in pushing the switch in the kitchen if i had used up all my hot water should heat up the water straight away for a limited amount of time, what happened was when i pushed the switch is that the socket for the lower(primary) element became live again for about 45 mins, i tested this outside of my cheap rate electric period, which is how i discovered the socket had became live.

So my question is has my immersion water heater been wired up wrongly when this house was built about 8 years ago, it appears to me that the boost switch in the kitchen should have been wired up to the top element socket near the water heater, as if you ran out of hot water, then pressed the boost button it will heat the water at the top of the tank giving you a 'boost' of hot water rather than trying to heat the whole tank by the lower element.

Any help would be much appreciated.

Mark.

 

[Steve]

The boost switch, I think, applies normal rate electric to the lower element. This is its job, I think these switches are designed for where theres only one element. Cant be sure though. If I'm right its doing its job right, but then you have no control over the top element from the kitchen.

 

[Mark5290]

Thanks for the reply, yes i could understand how it works it if there was only 1 element, i do sort of have control over the top element and that is just to leave it permenantly switched off, i do not use a lot of hot water so have never needed to press the boost button.

Could it be that whoever installed the electrics did not install the immersion heater, so wired up the place for a single element water heater, but then a decision was made to fit a 2 element heater instead

 

[Steve]

By the way, the "boost" button will not provide instant hot water when all the hot water is gone.

When the water runs cold, you'll need to turn it off, and put the boost on, so it has chance to heat the tank of cold water you've just given it

Those heaters are only 3kw each. For comparison, I have an instantaneous gas boiler which applies about 14kw of heat to my water in order to provide instant, powerfully flowing hot water.

 

[Mark5290]

Steve - is my understanding of how the boost works on a 2 element immersion heater correct as in it should heat up the top element when the boost button is pushed.

 

[RF Lighting]

The off peak element will be the bottom one. It heats the entire cylinder.

The peak (boost) element is the top one. It only heats the top half of the cylinder (as heat rises)

 

[Mark5290]

The peak (boost) element is the top one. It only heats the top half of the cylinder (as heat rises)

So it should have a permanent live feed then?, and cut in/out whenever the temp of the water gets low at any time of the day?, also is it right like steve says and the boost button in the kitchen only operates the bottom element.

 

[RF Lighting]

No, the boost button does the top element, as it takes less time (and electricity) to only heat half of the cylinder.

The boost should work at any time of the day

 

[Mark5290]

My boost button only operates the lower element.

 

[ebee]

loolks like it`s connected arse about face.
botoom off peak = half price full tank.
top = standard rate = full price half tank.

 

[kai]

In a modern Economy Seven immersion heater installation, there should be two elements, one Top and one Bottom, each fed off its own 13amp fuse-connection unit.

The bottom feed is run from the storage heater consumer unit, off a B16 breaker, while the top is run off another B16 breaker from the normal consumer unit.

The Boost switch should be wired to control the TOP immersion, and only engaged if you happen to run out of hot water.

The bottom immersion should only start up whenever the cheap rate supply is energised by the Board's timeswitch controler.

 

[Mark5290]

Thank you everyone for your help,

while the top is run off another B16 breaker from the normal consumer unit.

So are you saying that the 13 amp fused wall socket near the immersion that is connected to the top element should be live all the time.

The Boost switch should be wired to control the TOP immersion

How is the the boost switch wired to control the top immersion?, if the wall socket that feeds the top immersion is live all of the time, then i would have expected to see another wire going into the top element controller to tell it to switch on/off, but there was not another wire.

Or

Does the wall socket that feeds the top immersion only become live, therefore supplying power to the top immersion element and controller when the boost button is pushed?, my wall socket for the top element is live all of the time whether the boost button is pushed or not.

 

[Steve]

Does the wall socket that feeds the top immersion only become live, therefore supplying power to the top immersion element and controller when the boost button is pushed?, my wall socket for the top element is live all of the time whether the boost button is pushed or not.

Jackpot.

 

[2scoops0406]

I have an instantaneous gas boiler which applies about 14kw of heat to my water in order to provide instant, powerfully flowing hot water.

What, you bought a boiler off your Mum? I guess you just need a house to put it in

Tonight Matthew, I'm am going to be Thermo !!

 

[Mark5290]

Gonna have a word with my LL about it, if it has been wired up incorrectly, then the chances are that all the other houses in this smallish development have been wired up incorrectly then.