Hot water boiler keeps building pressure

I replaced fill valve because it was not working. Then I replaced expansion tank and air scoop because I found a crack in air scoop. I shut the cold water valve off to the boiler to see if that would stop. Customer called me and said pressure relief valve leaking water again.
If someone could help me with this problem?
Also it’s 2 zones with circulation pumps being controlled by 1 thermostat and all baseboards have bleeders on them.


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