New record temp for the year on Sunday 14th Sept. 87.6C at top of tank. I put the second set of 20 tubes in at the end of August, but there haven't been many good sunny days since then (and us being away obviously lets the temp rise higher due to zero usage).
I've set up more sensors on the tank so I now have it monitored from top to bottom in 5 steps:
http://aleph1.co.uk/munin/wookware.org/control.wookware.org.htmlThat missed the high-point because the router was turned off whilst we were away for the weekend, so look at the logs on the control-box itself for the full story:
http://wookware.dyndns.org/munin/localdomain/localhost.localdomain.html(note these are about 1hr behind because it takes the poor little thing some time to do all the sums for the graphs :-)
I have also instrumented the heat exchanger so there will be more graphs soon.