Fitting immersion heater to hot water tank

[neil7744]

Hi,

Just got a few questions about fitting an immersion heater to my hot water tank (as currently its just heated via my boiler).

I have a 900 x 600 96 ltr vented indirect cylinder and would like to know the following...

1) what size immersion heater should be fitted? (the physical size and power)

2) how should the immersion be wired? What size cable? Via a fused switch? What size mcb?

3) under regulations will this require it's own circuit from the consumer unit?

I realised after being away at the weekend and having the hot water and heating switched off that if my boiler fails I have no way to heat water and so therefore would like to install an immersion as backup.

Any advice would be appreciated.

Thanks

 

[HERTS P&D]

I have a 900 x 600 96 ltr vented indirect cylinder and would like to know the following...

1) what size immersion heater should be fitted? (the physical size and power)

27"- 3kw

2) how should the immersion be wired? What size cable? Via a fused switch? What size mcb?

2.5mm immersion cable to a switched spur with single radial wire back to fuse box, fuse at 20amp.

3) under regulations will this require it's own circuit from the consumer unit?

Yes

Hope that helps

Andy

 

[muggles]

I assume you've checked you actually have somewhere to put it, IE there's a hole for the immersion that's currently capped off? If not, you can't make one, you need a new cylinder.

It's cheaper to heat the cylinder using your boiler than it is using an immersion, and it's faster too, so as you have suggested the immersion should be backup only.

You'll need to get a qualified electrician to do the electrical work.

 

[denso13]

If not, you can't make one, you need a new cylinder

On of my first jobs was fitting loads of thesehttp://www.howden-electroheating.com/pi/pi-dh.html

 

[muggles]

Oooh that's novel, not seen one of them before...

 

[Agile]

Should be a fused at 13A switched spur.

Cable should be heat resisting!

Some use 1.5mm2 cable which is only JUST adequate!

If there is no boss on cylinder some will solder one on! Not rec for DIY though!

Tony

 

[Charnwood]

If not, you can't make one, you need a new cylinder.

Can't you? What are 21/4" Essex Flanges designed to do then?

 

[neil7744]

Thanks for the replies. Exactly what I was after.

 

[JohnD]

Should be a fused at 13A switched spur.

No it shouldn't.

It should be supplied from a dedicated radial with a 16A MCB. No duplicate fuse required at the switch.

 

[muggles]

If not, you can't make one, you need a new cylinder.

Can't you? What are 21/4" Essex Flanges designed to do then?

Excuse my ignorance...never seen one, will remember that!