Solar DHW with UniQ and PV Diversion

[DamonHD]

Another very basic question or two since no one has recoiled in horror so far!

 

1) "External immersion heaters are designed to directly heat domestic hot water (DHW) in a vented system."

My rad circuit is not vented so far as I understand it, but there is an expension vessel there and an emergency pressure relief value, so I am assuming that this would be OK.  But please say if not.

 

2) "Because the Willis Immersion is such a rapid water heater, it is not recommended for use in hard water areas."

Hardness is not going to be an issue as new mains water is not getting in as a source of calcium except for top-ups.

But are there other corrosion or similar issues that I should think about?

 

Rgds

 

Damon

[DamonHD]

Just for the record on this thread: the Sunamp Thermino 150 ePV and myenergi eddi are in and running, though we're not getting enough sun to give them a good workout yet!

 

A reminder of the full write-up link:

 

https://www.earth.org.uk/note-on-solar-DHW-for-16WW-UniQ-and-PV-diversion.html

 

And here is a live chart to keep you all on the edge of your seats:

 

https://www.earth.org.uk/_heat-battery-target.html

 

Thank you all for your advice along the way!

 

Rgds

 

Damon

Edited March 16, 2022 by DamonHD