Immersion Heater Lengths

cr0ft · Apr 30, 2015

Hi all,

Just a quick one. I have a customer who wants to replace their existing top of cylinder immersion heater (27") with a longer one. They want to use their solar PV system to heat as much of the water in the cylinder as possible basically.

I've found 36" ones online which will obviously improve things, does anyone know where I can buy any longer than that? The longer the better (no puns please) as it's going to heat more water in the cylinder.

Fitting another one lower down isn't really an option I fancy as it's an indirect cylinder connected up to an oil boiler and I don't fancy drilling through the bottom and missing the coil!

Thanks for all advice!

Ray Stafford · Apr 30, 2015

I've never seen longer than 36".

Leo21 · Apr 30, 2015

Ray Stafford said:
I've never seen longer than 36".

Oh that's it then, they can't possibly exist.

Best · May 1, 2015

If it is a vented cylinder you could fit a Willis external heater.
It uses a standard 11" element, but heats the cylinder from the top & will heat entire cylinder if on long enough. Very easy to fit if you have a 1/2" tapping (drain tapping?) near bottom of cylinder.
It's the quickest & cheapest way to heat some water in a hot cylinder for shaving, for example.