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L7224U - Outdoor Reset with Oversized Boiler & Baseboard?
I've got everything I need to install a Taco ZVC405-4 to clean up my zone valve wiring and give me priority for my Boilermate (pipe with zone valve).
I have a newer L7224U digital aquastat and I'd like to install the outdoor reset kit soon, so I'm thinking about using the "duu" option - ZR DHW Request. This will force the boiler to high limit for a DHW call, and will drop back down to the outdoor curve for space heating calls on the other 4 zones.
How should I be wiring this? My boilermate's aquastat will be wired to Zone 5 Priority on the ZVC, but the L7224U is looking for line voltage on the ZR contact.
Should I be using the ZVC's Zone 5 Pump End Switch contacts, with Common connected to L1 and N/O connected to the L7224U's ZR terminal? When the DHW calls, the zone valve will open, closing the end switch, which will close the Pump End Switch, which will supply 120V to ZR on the L7224U, which will power the circulator and fire the boiler to High Limit. Is this correct?
Nick Lester, Cranston, RI
Just a homeowner who loves to learn from others.
1948 3-Family Colonial - 2650sq ft - Originally 1-pipe steam - Removed in 2008 for 3 separate hot water baseboard systems. Wish I had known what I know now!