Only a third tank of hot water

[John kronberg]

I have solar panels and in the summer we use the power generated to heat the immersion hot water tank, the only problem is the element goes into the tank via a top entry thus only the top of the tank water gets hot. I have put a longer element in (27 inch) which just about gives a shallow bath full of hot water.
Someone has said that he as heard of some kind of tube that can be fitted around the element which will somehow circulate the water around the tank thus heating the whole tank.
Alternately is there some way of fitting a circulating pump into the system to heat the whole tank.
You advice will be greatly appreciated.

 

[ShaunCorbs]

Really you need a tank designed for that purpose

I'm guessing your cylinder is open vented ?

 

[Best]

A cylinder with elements at the sides would mean you could heat most of cylinder using the lower element.
If your cylinder is open vented, there is the alternative to simply having a Willis immersion heater fitted - (which is an external heater and adds heat immediately to top of cylinder and is therefore very rapid and will heat entire cylinder if needed)

 

[Dkdc71]

Just asking why are you even using the immersion in summer there should be plenty of sufficient hot water without having to use your immersion .is your solar system working properly or has it been checked

 

[Best]

Just asking why are you even using the immersion in summer there should be plenty of sufficient hot water without having to use your immersion .is your solar system working properly or has it been checked

I initially read it same as you. Think the OP has electric panels.

 

[Dkdc71]

Sorry just re read it again think your spot on Best thought he had a seriously f****d up solar system thanks

 

[Sharp Point]

I use to do a fair bit of thermal solar a few years back and every now and again we’d install a retro fit immersion coil, to overcome your exact issue we’d fit a destratification pump.... yes I know there’s the running cost, but that wouldn’t apply to your free electricity! I’d circulate the hot from the top with a bronze pump to the cold feed at the bottom.

Job done

 

[ShaunCorbs]

I use to do a fair bit of thermal solar a few years back and every now and again we’d install a retro fit immersion coil, to overcome your exact issue we’d fit a destratification pump.. yes I know there’s the running cost, but that wouldn’t apply to your free electricity! I’d circulate the hot from the top with a bronze pump to the cold feed at the bottom.

Job done

cant fit them on an open vented system

 

[Sharp Point]

cant fit them on an open vented system

Why not Shaun corbs?

 

[ShaunCorbs]

Why not Shaun corbs?

would pump over

 

[Sharp Point]

It doesn’t, trust me

 

[Dkdc71]

Agree with Shaun corbs not calling you a liar but never seen it done like that only ever fitted them on a how water return sealed system . Would the pump not Rob from the domestic side when the household supply is called for by constantly recirculating from the expansion back to cold feed . Without going to all that trouble would have replaced the cylinder for one with dual immersions in the side .did you never get problems with water fluctuating or pressures after the pump been fitted bogrodder?

 

[Sharp Point]

No, I never noticed a difference. But you’ve got to bear in mind you don’t need a fast flow, we cracked a bronze pump down via the gate valves . All it needs is a very slow flow rate and the delivery pipes were insulated well... oh and it was on a timer, so it wasn’t running 24 hours.

Regards to pumping over, theoretically it would/ should pump over if the circulation loop were to broken.. ie blockage/ valve, but as the water can move, pumping over is impossible. Similar to most pumping over situations on a y plan when the neutral zone gets blocked from baked on sludge.

 

[Dkdc71]

Thanks for the reply just to clarify are you talking about a sealed system have seen recirc pumps fitted as a secondary loop on sealed but not on a standard open system open system

 

[John kronberg]

Just asking why are you even using the immersion in summer there should be plenty of sufficient hot water without having to use your immersion .is your solar system working properly or has it been checked

Hi, my solar system only produces electricity, I do not have a solar system for the water stand alone, in the winter I use gas to heat the house and for hot water.

 

[John kronberg]

A cylinder with elements at the sides would mean you could heat most of cylinder using the lower element.
If your cylinder is open vented, there is the alternative to simply having a Willis immersion heater fitted - (which is an external heater and adds heat immediately to top of cylinder and is therefore very rapid and will heat entire cylinder if needed)

Hi, this sounds exactly what I am looking for. thanks a million and I shall be looking into this willis immersion and am sure I will be getting one fitted in the very near future. Thanks again.

 

[John kronberg]

I use to do a fair bit of thermal solar a few years back and every now and again we’d install a retro fit immersion coil, to overcome your exact issue we’d fit a destratification pump.. yes I know there’s the running cost, but that wouldn’t apply to your free electricity! I’d circulate the hot from the top with a bronze pump to the cold feed at the bottom.

Job done

I will look into the destratification pump as well as the willis immersion as Best has suggested.it will probally come down to cost and how much space there is to fit either. Don't worry about the running cost because the pump would run off the free electricity.
Thanks very much for your imput.

 

[Best]

Hi, this sounds exactly what I am looking for. thanks a million and I shall be looking into this willis immersion and am sure I will be getting one fitted in the very near future. Thanks again.

Here is a link to the exact heater type I mentioned.
Willis External Immersion Heater | Heating Parts Warehouse
Not expensive, as you can see.
But it requires some minor plumbing.
The Willis has to be installed vertically, (with electrics at base), somewhere fairly low at side of hot cylinder.
The bottom connection (cold return) of heater can be joined to the 1/2" drain tapping with copper pipework.
The top connection (hot flow) on the heater must be connected using copper pipe to tee to the vent pipe of your hot water tank ideally at least 500mm above cylinder to give proper circulation to keep the Willis heater loosing heat

 

[Ric2013]

On a tangent, this shows how ridiculous the incentives for solar photovoltaic are. A PV array owner receives a subsidy for generating electricity, and a small amount for exporting this to the grid (deemed to be exporting 50%). Because there is no incentive to export as much of the electricity produced as possible to the grid, installers are encouraging customers to use the electricity on site, such as by heating hot water, thus evading the intent of the original legislation.

The sad thing is that it would be better, from an environmental aspect, to release the electricity produced to the grid to be used for functions where only electricity will do, and heat the water using an efficient gas boiler, but, of course, the OP would be worse off financially were he or she to do this.