I am troubleshooting a problem that ocurred after I replaced the filter, heater and had to replumb. I have solar. When the solar 3-way valve turns of for the night, it looks like in addition to the solar panels draining as they should, my filter is draining back into the pool overnight. In working with the Autopilot people, they think that with my current plumbing (see the second picture here post290428.html), not only are the solar panels draining but also the filter is draining, which would make it hard to prime, and when the solar valve opens there is too much air in the system.
If you look at the second picture, the output of the filter goes to the check valve and from there goes to the 3-way valve. When the solar 3-way valve closes at night, the panels drain (as they should), but because of the 3-way, allowing draining the panels, the water from the check valve empties, no longer offering resistance to stop the water from the filter to drain.
They are suggesting that the output of the check valve to the 3-way solar valve should go up so that the 3-way solar valve is much higher than the check valve leaving the check valve with water in it to keep the flapper close through water pressure instead of allowing slow air leaks. Right now the multiport valve (filter) is level with the checkvalve and the 3-way valve, and with the solar side closed there is nothing to stop the filter from draining through the return. I can watch the check valve emptying. The path goes from the open side of the 3-way to the Mastertemp heater and out to the returns. Does this make sense? Thanks.
Here is the picture (second one) post290428.html