Doctor Evil wrote:

You now have a hybrid thermal store. Why did you add a plate heat exchanger?

Because we have very hard water, I suspected that the coil would scale
up within 5-10 years. Replacing a plate exchanger is easy.


How did you pipe the coil/plate?

The tank had several spare blanked off threads at different levels. I
just used a spare pair, one about 1/3 of the way up, the other near the top.


How does it perform?

There is little difference in performance. The only noticeable thing is
a small increase in hot water delivery, because of the lower resistance
of the plate exchanger compared to the coil.


--
Grunff