Why would my hot water tank have external heat exchangers?

[ajrtd]

Yes. I used to pay a lot less than those in picasso's link which made them cheaper than an equivalent phe.

 

[bernardgreen]

People who can afford a swimming pool can also afford to pay over the odds for the components needed to run it. Marketing gimmicks apply around domestic swimming pools 60,000 BTU is a very impressive heating capacity for their heat exchanger, 18Kw doesn't sound quite so impressive

 

[dilalio]

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.

Could you not contact the previous owner and get the details of the person who maintained the system?