opnspaces wrote:
In thinking about where you said the led was flickering when the hammering was occurring. Is there a faucet close to the water pump switch? maybe try turning off the faucet and simultaneously flipping off the water pump switch. I'm thinking the flickering LED might be from the pump trying to still push water well beyond the shutoff pressure and causing the LED to blink while it's hammering.
Yes, they are right next to each other.
Pressure switch is kind of what I'm leaning towards. Wondering if the dealer messed with the settings in a misguided diagnosis.
I may just buy a pump this weekend and stop. Learning about accumulators too, even if I do get this fixed, see value in adding one.