Pump is higher than pool behind a retaining wall which explains the suction check valve location. As for the solution I am going to make a union adapter to run the garden hose in the outflow of the heater to flush out any potential debris perhaps that got in the intake before it was hook up. Other than that I am going to just make sure bypass is open when it’s not heating. Pump runs high once a day which will flush the heater daily, I understand leaving stagnant water in then is is an issue we aren’t cracking that check valve at normal 20gpm flow with bypass open.