See the picture below showing the pipes running to and from my solar pool heater. The left pipe feeds the solar panels (water from the pump flows up to the panels), the right pipe is the return path (heated water returns from the panels and goes to the pool). The bypass valve looks to be a standard Pentair 3-way valve. For the past year I've been operating my system with the little "off" tab of the bypass valve pointing left, and the handle pointing right. I thought this meant water was flowing to the solar heater, but I believe instead water was going the path of least resistance and flowing to the right, completely bypassing the solar heater. The right isolation valve (return path) was also closed this whole time, leading me to believe that was the case since everything seemed to be working properly -- water was coming out of the jets, pool cleaner was running, etc. I don't know what the inside of the bypass valve looks like, so can someone confirm that that's probably what was happening?
Where ever the Off points will be the part that is shut off. In this picture the water will hit your three way, hang a right, and return to the pool.
For solar heating your three way's Off should point to the 3 o'clock position, and of course open that shut off valve on the right.
Thanks for the reply. So for the past year I had been running the system with the "off" tab pointing to the left. I would assume then the water was flowing to the right and bypassing the solar panels? Can you confirm?
If the off tab was at 9 o'clock, all three ports were open. If that was true and that other valve on the right was closed, the water would certainly bypass the solar. If that valve on the right was open, that water most likely bypassed the solar since that's the path of least resistance.
Those handles come with two pins that fit the holes. These can be inserted so the valve will only close the correct ports. Once you determine the correct positions, you might be able to improvise something like that.
Great, thanks for the response!
i have solar panels also. A good test that they are working, once you do what the people above are suggesting, is to put your hand by the output into the pool. In my case the water is 5-7 degrees warmer.
You can feel the difference.