VAILLANT DIAPHRAGM PUMP

[mogget]

bit late for that, the savings have already been spent on the cylinder and panels

Quite! Maybe the OP is a trader in gas and oil futures and knows something we don't

 

[ddk]

cant think why anyone would go through all of that trouble and expense then try to save a few quid by re-using a diaphragm pump

maybe he just LOVES recycling lol

 

[8aviashusband]

Going back to the original question ....
If you look at several threads about secondary DHW circulation, the question is sometimes asked about alternative pumps to the Grundfoss bronze bodied ones (because they look like a heating circulator, but are 4x the price). So when I see a cheap pump advertised that might - just MIGHT - do the same job, a few enquiries are justified. My query got answered in the second posting (by Gasguru), and the answer was NO.
I didn't expect a discussion about solar pre-heating of water. (There's a thread touching on elements of this, too.)
Thanks to those who contributed useful replies.

 

[Deleted member 105431]

Going back to the original question ....
If you look at several threads about secondary DHW circulation, the question is sometimes asked about alternative pumps to the Grundfoss bronze bodied ones (because they look like a heating circulator, but are 4x the price). So when I see a cheap pump advertised that might - just MIGHT - do the same job, a few enquiries are justified. My query got answered in the second posting (by Gasguru), and the answer was NO.
I didn't expect a discussion about solar pre-heating of water. (There's a thread touching on elements of this, too.)
Thanks to those who contributed useful replies.

how about a diesel pump off an old banger, that "MIGHT" do the job? Or how about a water pump from a car engine? Or even an air source heat pump? Or a ground source heat pump?

They are pumps after all. . . . .