I'd be interested in any answers to that too - don't have solar panels as yet but thinking about it.  And wondering if they could run some underfloor heating.  The sun was so hot over Christmas I'm sure we could have had central heating for (almost) free

If you go to the Navitron (UK) website or even better phone them they will be able to advise you as they are very helpful and we there before all of the 'new' solar companies started up.

I think covering the panels or draining the entire system (if water based) when you are away was some advice I had.

http://www.myabruzzohome.blogspot.com

... have a look at your solar controller... if it is just a simple DeltaT switch then you can get overheating problems and you might have to upgrade it to something a bit more dedicated. The better ones have a'holiday' setting where the pump runs heat back out through the panels at night so each day starts with a cool tank.  Balancing tank size with solar panels is obviously important. I'd happily comment if you give details.

  Thanks everyone for your replies.  

  Hi Sagraiasolar, Our sysyem is a Supersolar passive system with a panel mounted tank.  If the water is turned of and the tank empties will the panels themselves be damaged by overheating or is that unlikely?

ah... one of those.  I'm just aiding the removal of one because as it heats fresh water there is a build up of lime scale which has clogged it up. In some ways they are like giant solar kettles. The replacement system will have some nice new panels with a pumped circuit to a coil in the new heat bank.  I digress... so back to your tank... I don't suppose you want to get on the roof to cover it.... leaving it empty will definitely damage it because the panel itself is filled with 5 litres of antifreeze/solar fluid and this will boil almost as soon as the sun hits it. All I can think of at the moment is to fit a time-switch and solenoid valve to a hot tap for a daily timed heat dump.... 300 litres into the pool?   You can convert it to a pumped circuit + (bigger) cylinder just by removing the tank on the panel, so that might be a longer term option.

Thanks for the info.  I will have to get on the roof and cover the panels.  Next year I'll go back to the UK in the winter! 

I was interested by this product, not sure how it works or indeed the cost but looks pretty simple to install.

Aviso please..

http://www.solcrafte.com/en/innovation

Bunterboy.... just did a reply when the forum site hung so here we go again.  The web site is a bit furbo eg...'savings of up to 80%'  er would that be 5% then?   and 'hot water 365 days a year'.... not out here, must be talking about Arabia.   This is just a slab tank in the sun so do we expect freezing and boiling problems?   What we really need is big panels - 5mq + - loading a big tank, all with good control and a pressurised circuit with antifreeze. Efficiency is not relevant because the sun is free.. all we need to know is the cost per mq. of panel... invariably some simple flat panels are best.

I did a little more sniffing around and found them on sale on ebay.it

http://www.ebay.co.uk/itm/PANNELLO-SOLARE-SOLCRAFTE-200-/220852312776?pt...

Hard to believe they would try to market a slab tank in a glass box as something cutting edge!

I'd love to make it to one your seminars to get fully "genned up."

...Bunterboy..... the next one is on the 23rd Jan!

I'm working in the UK , but hopefully in the autumn I could manage all being well.