Why would my hot water tank have external heat exchangers?

[garyo]

Hi chaps,

I've just moved house and found that my hot water tank has a couple of external heat exchangers rather than the usual internal coil. The boiler is downstairs around 10 metres away.

I'd rather these weren't there because they're causing me a problem in terms of adequately insulating that area of the house, so I'm wondering what were the normal reasons for doing this? We live in a hard water area, so could it be to move the limescale problem from the tank to the (more easily changeable) exchangers? The house is a 1960's build, and boiler looks like it's 20 years old.

Thanks

Gary

 

[oldbuffer]

Pictures not visible.

Could your hot water cylinder be a thermal store?

 

[garyo]

I've changed the picture.

Could your hot water cylinder be a thermal store?

Possibly - but it feels like they get hot when the boiler is heating the hot water, rather than when we're drawing the water off. I'll run that test again tonight. Still, if that was the case - what's the reason? Is it to move the potential limescale problem somewhere more accessible again?

[Edited to add - you know what - there's a log burner downstairs that (apparently) also heats one of the radiators. I think I need to trace the pipework to see whether it's also linked in to the hot water system]

 

[leakydave]

Thermal store I expect

 

[Dan Robinson]

How can you make such a mess of soldering Yorkshire fittings ffs? Industry is gone to the dogs.

Can we have some more descriptive pics?

 

[Agile]

Don't know what Dan is looking at as I cannot see any pictures!

But I am sure that it must be a thermal store heated by gas boiler and the wood burner.

Water can be very hard in parts of Berkshire.

It would be best to add an electrolytic water conditioned on the incoming cold water.

Tony

 

[Dan Robinson]

I'm looking at the picture in the OP

 

[garyo]

Thanks for the replies. I'm struggling to get more informative photos because so many of the pipes disappear behind studwork, in to the floor, or in the case of the cylinder cupboard, in to the loft space. I will take some cylinder photos and diagram what I can tonight.

 

[Agile]

Visible now.

That's interesting. Those are the, usually US made, type often used on swimming pools.

Tony

 

[PullerGas]

Thermal store I expect

Dave, if the heat exchangers are not within the cylinder it's a Heat Bank. These look like Yanky heat exchangers, not seen that type before either side of the Pond.

OP Heat Banks & Thermal Stores are sludge buckets.

 

[Agile]

I have seen them before but on swimming pools!

 

[garyo]

I only moved in two weeks ago but I think I'd definitely have noticed if there was a swimming pool!

Checking I understand this correctly then, what we suspect is probably happening is the oil burner is heating the hot water in the tank using one exchanger, and the log burner using another. When I turn on the hot tap, will I be using the actual hot water that's in the tank, or am I probably drawing cold water through the tank using a third built-in coil heat exchanger?

Interestingly I can see no sign of pumps other than two in the downstairs boiler cupboard (presumably one for CH and the other for the HW loop) So the two heat exchangers must be moving the water between them and the tank using plain convection?

It all seems over complex to me, but I've always fancied some solar-thermal panels so perhaps it's not so bad that it's like this. I'll do more digging around tonight to trace the pipes.

 

[picasso]

Blue ripple engineering ltd based in chelmsford ,essex, now defunct i think

https://www.poolandspacentre.co.uk/products/blue-ripple-stainless-steel-heat-exchanger.html

 

[ajrtd]

I used to buy them from here http://www.architecturalstainless.co.uk/

 

[PullerGas]

I used to buy them from here http://www.architecturalstainless.co.uk/

Thanks AJ. I guess they had a high flow rate for pools? They look seriously expensive in comparison to plates?