no back up immersion

[mazperks]

Hi, a water cylinder is heated by economy 7 imm heater. There is no secondary back up heater for boosting if required.
Is it acceptible to feed in a second switched supply via a junction box to the heater for anytime boosting.
Thanks Ian.

 

[Chri5]

Get a duel element, main one runs eco7 and the smaller one at the top is the boost /top up from the non eco7 main.

 

[EFLImpudence]

What Chri5 suggests is a lot of work.



What you describe is achievable with a change over timer unit.

Google 'Horstmann E7'.

 

[Taylortwocities]

What Chri5 suggests is a lot of work.



What you describe is achievable with a change over timer unit.

Google 'Horstmann E7'.

The Horstmann E7 etc timers are not suitable if you have a separate off peak power feed to your immersion. You can easily tell this.
Do you have two consumer units? If so, tyou probably have a separate off peak feed.
Post a picture of your meter and fuseboards if you not sure.

It has to be the type of installation where you get a power feed to your immersion etc 24hours a day. That means you have an off peak tariff arrangement where the electricity you use FOR ANYTHING at off peak times is cheaper.

 

[EFLImpudence]

Apologies if I used the wrong term but there are such controls available.

http://www.horstmann.co.uk/download...r-Heating/BX2000-InstallationInstructions.PDF

 

[Taylortwocities]

That will do the job.

But (there is always a but) mazperks will need also need a permanent feed for the on-peak supply to the location of the immersion heater.

Ideally this will be a separate circuit from the fuseboard to comply with limitations/guidance about water heaters and loads >2KW on ring finals.

 

[ban-all-sheds]

What Chri5 suggests is a lot of work.

A lot of work to replace the element with a dual one?

Maybe if the old one won't come out, but otherwise....

Main Q about that plan though - mazperks - where is the existing heater, at the top or the bottom of the cylinder?

 

[EFLImpudence]

A lot of work to replace the element with a dual one?

Well, compared with getting the present element to work as required it is.

Do they do 11" dual elements?

 

[mazperks]

Hi to all that replied, and sorry for not being able to get back on line till now.

To clear things up, this was originally a 2 immersion system, (one economy 7
and one anytime boost ) I'm assuming this as there is a second unused supply from the main fuse board to an immersion spur, but there is only one heater in the tank (at the top) fed from economy7. It would seem the tank has been replaced at some time for a single immersion type.
So back to my original question, can I also supply this single immersion from the unused spur for anytime boosting. Iwould run both supplies through a junction box and single flex to tank.

Ian.

 

[EFLImpudence]

Just to clarify - out of interest -
does your element enter the (actual) top of the tank vertically or
the top (of the side) horizontally?

Anyway, you cannot just connect the off-peak and 24 hour supplies together in a junction box.

You need something like I linked above so that both supplies will not be powering the element at the same time.
This is also useful in case you forget to turn it off.

 

[mazperks]

Thanks efl,
The immersion goes down vert from the top.
Can you explain why the two supplies can't run together, especially if the day boost is switched.
Cheers Ian.

 

[mazperks]

Thanks efl,
The immersion goes down vert from the top.
Can you explain why the two supplies can't run together, especially if the day boost is switched.
Cheers Ian.

 

[EFLImpudence]

Well, the off-peak is switched too, or should be.

The danger would be if both were on at the same time.
Therefore something should be in place to prevent this.
A simple change-over switch would do but that would be inconvenient so a device designed specifically for this task is best.

One reason is - the single immersion cable, 25A max., could, if both supplies were on at the same time, only be protected by two 16A feeds, i.e. 32A.

Another is - back-feeding which would switch on all off-peak devices (storage heaters?) unless you (or the kids) remember never to switch on the boost without switching off the off-peak all the storage heaters would be supplied through one (I presume) 2.5mm² cable.

Edit - although it would blow 16A the fuse.

 

[EFLImpudence]

Also, as it is a top-entry immersion (how did he know?) a dual element could be fitted.

Best of both worlds.

 

[mazperks]

The dual element imm heater sounds like a good idea , do they have separate terminals for off, and on peak supplies, so as to utilize my unused supply cable.