“Just installed my radiant system but without any venting. Spent hours trying to purge the air out with minimal success while listening to the cavitation in my new Taco X-Pump Block. Installed this dude and cavitation gone immediately, smooth quiet operation. Only complaint is the bottom port for the expansion tank is 1/2 npt, NOT 3/4 as listed in the specs. Simple solution but an annoying last minute trip to buy the correct fitting. Works great. Note: bottom port is 1/2 NPT”
