"NY" wrote in message
o.uk...
"The Natural Philosopher" wrote in message
...
I don't know how the DHW works. Perhaps a second stage heat pump. She
seems happy with it but the house is now on the market:-)

DHW uses heatpump as preheater then immersion.

So you have to heat a cylinder of water in advance, rather than having the
heat-on-demand of a combi boiler. Yet another nail in the coffin for the
system as far as I am concerned. Having to plan ahead when you are going
to have a bath (or keep the cylinder permanently hot) is a real retrograde
step.

Trivial to insulate the cylinder well enough so you dont waste any heat.