Immersion Heater

[ICARUS]

Hello, Would be grateful of some advice, I am looking to install a second immersion heater element as a backup should the Central Heating system breakdown. In terms of connecting it to the household electrical supply, can I spur off a plug socket to provide the supply ????. If not what would you suggest.

Thanks ;-}}}}}}

[Chri5]

Whats the size of each element in watts, and is the element already in use on it's own circuit and fused at the CU seperately?

Do you have any idea what the cable size is on the existing element?

[ICARUS]

Chri5 wrote:

Whats the size of each element in watts, and is the element already in use on it's own circuit and fused at the CU seperately? Do you have any idea what the cable size is on the existing element?

Hello, It is a new element that I want to add to the water cylinder, its rating is 3KW, I am unsure as to whether the existing element is fused seperately. There is no indication of this on the CU.

Cheers

[Steve]

One immersion heater should provide more than enough hot water, in the event of a boiler breakdown. Why have 2 'mersions? And whats the chances of a boiler breakdown? If it does breakdown, it'll probably be working again within 24 hours.

And the first 'mersion should be on its own circuit, as will this new one you are wanting to install.

[Spark123]

It is not normal practice to supply an immersion heater from a socket circuit, they are normally connected to their own radial circuit.

[ICARUS]

Hello,

The reason why I am wanting to install a second immersion heater is that the current one is controlled by the boiler / timer and cannot work independently. i.e if the boiler does not fire up you cannot turn on the water immersion heater.

The boiler has broken quite a few times and it means that we are left without hot water even with British Gas cover for at least two Days if not more if they don't have the parts.

So I want an independent immersion heater that I can just switch on if the boiler packs up.

Cheers

[JohnD]

If you are sure it is an ordinary electric immersion heater that is already installed in your hot water cylinder, then a better solution would be to have it rewired in the usual way - that is, with a separate radial circuit fused at 15 or 16Amps from your consumer unit. It does not have to go through your boiler controller. This can have a timeswitch or a plain switch which is normally placed in the airing cupboard adjacent to the cylinder.

If you are not experienced at electrical work it would be better to have a recommended local electrician do it. installing a new circuit is notifiable work. I would have expected a dedicated circuit to have been installed already if it is a reasonably modern house, but I gather you can't see one.

It is not correct to supply an immersion heater from the socket ring circuit.

[plugwash]

i think a second immersion heater is overkill

personally i'd put a plug on the existing immersion heater and then have a pair of sockets, one connected to the existing supply for the immersion heater and one wired on the upstairs ring in the normal way.

then when the heating system dies just unplug the immersion heater and plug it in directly.

its not best practice to have an immersion on the ring but since the setup is only for occasional use and upstairs rings are rarely heavilly loaded it shouldn't be a major problem.

[ICARUS]

plugwash wrote:

i think a second immersion heater is overkill personally i'd put a plug on the existing immersion heater and then have a pair of sockets, one connected to the existing supply for the immersion heater and one wired on the upstairs ring in the normal way. then when the heating system dies just unplug the immersion heater and plug it in directly. its not best practice to have an immersion on the ring but since the setup is only for occasional use and upstairs rings are rarely heavilly loaded it shouldn't be a major problem.

This sounds like a good idea, so are you saying that I should attach a domestic plug to the immersion heater coax, and then install two domestic sockets one making use of current Immersion heater electrical supply and one connected to the upstairs ring and then just unplug and plug accordingly ?.

[plugwash]

ICARUS wrote:

This sounds like a good idea, so are you saying that I should attach a domestic plug to the immersion heater coax, and then install two domestic sockets one making use of current Immersion heater electrical supply and one connected to the upstairs ring and then just unplug and plug accordingly ?.

its not coax its heat resistant mains flex but yes that is what i am suggesting.

[kevnurse]

I'm confused. I've never heard of a gas powered water boiler not using its own hot water to supply a primary heater in the DHW tank. Are you telling us that the boiler timer switches an electrical supply to your hot water tank? That is a very expensive way to routinely heat water. 1 kw/hr is 1 unit, so you're spending approx 24p per hour to heat your water (I accept that it takes less than 1 hr to bring the tank up to temperature) Furthermore, if your normal imm heater is 3 kW, you should not be passing that kind of load through a boiler timer.

I hesitate to ask this, but are you absolutely sure that you have an electric immersion heater as your normal hot water heater?

[JohnD]

Can you post a picture of the hot water cylinder, showing the pipes and cables going into it?

We like pictures!

[securespark]

I'm confused, too!

Boiler programmers are limited to 3A maximum, so cannot control anything other than boiler, stats & pumps, etc...

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"

[Steve]

securespark wrote:

I'm confused, too! Boiler programmers are limited to 3A maximum, so cannot control anything other than boiler, stats & pumps, etc...

. . . contactors, relays etc . . .

[JohnD]

maybe it isn't really an immersion heater.

Roll on the photos!