On Fri, 07 Nov 2008 11:53:34 +0000, Andy Kirkland
wrote:

wrote:
On Fri, 07 Nov 2008 11:08:15 +0000, Andy Kirkland
wrote:

Hi,

I've got a hot water tank (approx 4' high) and it's currently got a tiny
immersion heater element (11" from what I can guess off the label and
also the pitiful amount of water that a single heating produces).

I would like to replace it to enable it to heat the majority/entire
tank. Is there any rule of thumb/limit on what length of heater you can
use versus the size/height of the tank?

Andy

Can't you just measure the depth of the tank and buy one to fit ,like
a 24 " one for example.
I'm assuming there is enough room above the tank to let you get a
longer one in .

I was working on that theory.... I should be able to get a 36" element
in. I was just wondering if there were any guidelines regarding length
of element/proximity to side of tank etc.

Andy

I'm assuming that the immerser fits straight down the middle ( or does
it?) .If so then it won't be any nearer the sides than the old one .
I know that some fit in sideways and some ( I think) are at an angle .
You still have 12" between the end and the foot of the tank ( less an
amount for any concave in the bottom of the tank which you won't be
able to see unless you remove the tank )and allowing for any sludge at
the foot of the tank .
Does this help...it suggests 27" is the most common size
http://wiki.diyfaq.org.uk/index.php?...s#Element_Size