External destratification pump

[TedStriker71]

Hi Guys,

This may be a non starter but it was an idea that popped into my mind so thought I'd ask the knowledegable pople on here!

I have a unvented hot water cylinder heated primarily by gas boiler but it also has an electric immersion heater. I also have solar PV panels and plenty of spare electricity over the summer months. I have a immersion diverter to feed any unused power inot the immersion heater but as the immersion heater is fitted half way up the cylinder all I get is half a tank of hot water, not enough for a decent bath and I'm exporting quite a lot of electricity on a decent day.

So my question is - is there a way of fitting an external pump to the cylinder to 'mix' the hot water from the top with the cold at the bottom and allow the immersion heater to heat the whole tank?

Thanks!

Ted

 

[cross thread]

Has it not got a lower immersion position ? Most do

 

[TedStriker71]

Has it not got a lower immersion position ? Most do

Unfortunately not, just a single horizontal immersion heater half way up.

 

[Razor900]

It can be teed into the cylinder inlet.

It will need lots of insulation though and you can't use placcy pipe

 

[OvertonPlumber]

I've got the same problem on my solar cylinder which has the boiler on the lower coil and the solar on the top coil. Its only a temp solution its an old oso 210 solar must be 20 years old. I've got a new horizontal joule in the extension but it's not piped up yet.
I've just ordered a plastic bodied wilo. I've got 2 spare 1/2 wet pockets. But as you say could just pump of hot into cold feed.

How's about redirecting the destrat through a stainless steel towel rail

 

[Johntheo5]

A external immersion like the Willis can heat the whole cylinder but needs very careful installation with 22mm piping and (in the one I gave some advice on) the installation of a pipe stat to work properly. Also, a 2/2.5kw element will work better than the normally supplied 3kw.

 

[TedStriker71]

It's been a while and I'm just revisiting this idea. I've attached a picture of the unvented cylinder (please ignore all the mess, it's a work in progress!). The red pipe is the 22mm hot outlet from the top of the cylinder and the dotted part goes off to the rest of the house. The arrow points to a 15mm take off point for hot water to a digital shower mixer. Would it be possible to use this take off point as the 'feed' for a destrat pump? Also, would the blue section of pipe be usable as the 'return' from the pump if a suitable tee was cut into it?

Another question - would it be ok to use flexible push fit piping for the connections to/from the pump?

Thanks!
Ted