Hi Chris,
the white colour is the old water in the solar heating panel storage tank, it should go away soon and run clear. They haven´t ever been used until someone moves in but the water has been in them for years, bubbling away in the sun.
The light on your boiler means you have the boiler turned on which is not really necessary in the summer unless you want a really hot shower/bath.
The switch for the boiler is right where the light is, 45 degree turn to off. There´s a temperature gauge on top of your boiler which will show you how pleasant the water temp can be once you use only solar heated water, should be about half way between hot and cold.
Hope this helps, I´m in 163 but not right now..
Mike