shadowman
06-01-2009, 10:53 AM
In the late afternoon, when the sun is moving off my solar collectors, the automatic valve will partially close, then move again a little, and may eventually stop in a random position. If I manually switch it off at the panel, it works fine. Does this sound like a bad thermistor on the roof? The first few years that we lived here it worked fine, but last season and now this year it is doing this intermittent behavior.