Indirect thermal store?

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OK. Does anyone have a complete schematic diagram for that kind of arrangement?
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I'll scribble something down after I've had my tea.

This is essentially what I have. 160kW h.ex, 4 gall F&E tank, 120l cylinder set to 65 deg C. Enough for 2 consecutive showers. Some improvements could be made.
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Fantastic. Thanks. How about pipe diameters if you don't mind?

Do you know if the cylinder can be located in the cellar?
Fantastic. Thanks. How about pipe diameters if you don't mind?

Do you know if the cylinder can be located in the cellar?
Everything except for pipes carrying mains pressure is 22mm. 15mm the rest, but then I only have a 1/2" rising main.

Cellar considerations: Note that the F&E tank has an overflow warning pipe (not shown) that goes outside. But then the tank and cylinder could be filled from a hose, and forget the float valve. The practicalities of draining would need to be thought through.
Some pros on here might want to comment.
160kw based on what?
No idea - probably some very unlikely temperature differences. I looked at the rating of the ones Gledhill use on their kit and went a bit bigger.
No way it'll be anywhere near that figure in practice.
I've been Googling more about thermal stores and saw that the company Thermal Integration Ltd have products like Heatbank Pandora and HIUs. Their brochure says that the Pandora has no need for any discharge pipes. How does this work?

And I have never heard of HIUs either so I'm not sure what are they.

Can someone here please enlighten me?
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I don't think you'Il be needing an HIU...

That Pandora is very similar in principle to the diagram I drew.

There are no discharge pipes because the hot water is not stored under pressure. Contrast with an unvented cylinder where the discharge pipe is an essential safely feature to prevent dangerous pressure in the cylinder in the event of a failure of the other heat-limiting controls.
Thanks for the clarification.

Do you have any pictures of your heat exchanger and plumbing?
Some improvements could be made.

You could have used a bronze pump and let the gravity supply some of the outlets. Kitchen sink, bath.
Then in a breakdown situation you still have hot water.

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