Diagnosed issue with hot water with dual 50 gallon electric gas water heaters piped in series in basement utility closet. No power was getting to secondary heater with dedicated recirculating line. Was able to reset electric water heater and gain functionality. Check pressure on home at 79 psi. Noticed undersized thermal expansion tank for multiple water heaters. Replaced PRV on 1 inch PEXB line. Furnace and installed new 5 gallon thermal expansion tank in secured to wood framing in utility closet. Pressurize system slowly and let out all air of system in three stories before turning on recirculating pump.