Anyone think this could work? Mainly I'm trying to find a cheap way to control my solar heater.
Get a 1.5" Sprinker valve that runs on 24vdc, then connect that to a cheap furnace(or other kind if it will work better) thermostat. Find out how the thermostat senses temp and move it up by the solar panels so it senses the panel temp. When the thermostat senses the panels are hot(like sensing a room is hot in a house), it will send power to the sylinoid valve which will open and let the water flow to the panels. I figure I could gather all this stuff for <$100.
Any thoughts? I just don't want to shell out $200+ on a "real" solar control. I've also though about using the thermostat already built into the Spa pack to do this. Either disconnecting the terminals from the heater and to a pump, or to a valve. Then when the Pack would normally send power to the element it would go to the valve or pump.