Oops. Hot Water Kills Grass.

When I commented on the 11 December 2007 about the solar water heater which The Cottage has I mentioned that the water vented when it got too hot. Subsequently we discovered that the near-boiling water venting onto the roof so forcibly found it's way into places it shouln't have gone. Because it was so hot it also melted the plastic downpipes. They were subsequently replaced by steel ones. This summer the weather has been very hot and the sun fierce and I've been using as much hot water as I possibly can. It doesn't vent now until about 93 deg c which is pretty near boiling point. The problem? It overflows onto the grass: a huge cascade of near-boiling water straigtt onto the grass - presumably because it vents too quickly for the drainage system. It's a good job no-one was underneath at the time.

Solar Heating

The Cottage has a solar water heating system and very efficient it is too. When I came the system had only just been commissioned and the water temperature was 24 deg. It went up to 29 deg on the first day (which was dull and overcast). I used the electric boost to get it to 45 deg. It now stays between 65 and 75 deg without using any electricity.

Until one day that is when it blew it's top. When I'd left in the morning, despite a very long shower, the water temperature was at 85 deg. Well the system soon gets alarmed at that and apparently - I wasn't here but the digger driver saw it all - it suddenly vented and the Cottage looked as though it was steam driven. I'm told the venting was quite spectacular.

It must have got rid of a lot of water because the temperature was down in the low 50s when I got home and dropped to 45 by late evening and then dropped more over night. It subsequently increased again and now seems to keep between 60 and 80 deg. How often it vents though I don't know.