2-Way Zone Valve

This collection covers 2-way zone valves for hydronic heating and cooling. It includes Caleffi Z-One 24V normally closed valves with end switches in sweat, union press and inverted flare, with Cv from 3.5 to 7.5, MrPEX Systems NPT zone valves with actuators, and Honeywell Home V8043E QuickFit 24 Vac valves in 1/2 to 1 inch.

Decide between normally closed and normally open operation, and match actuator voltage to the thermostat or zone control. Choose an end switch where the valve must call the boiler or circulator. Size by Cv and pipe size rather than pipe size alone, confirm the close-off pressure rating, and pick the connection type that fits the piping.

See also: 3-Way Zone Valve, Zone Valve Replacement Heads, Switching Relays.

Popular part numbers: Honeywell V8043A1011, Honeywell V8043E1137, Honeywell V8043F1036, Honeywell VCZAR1100.

Frequently asked questions

How do I find the exact replacement valve?

Read the model number on the old valve, for example V8043A1011 or V8043E1137, and order the same number. The letter after V8043 marks the version, so match the full number.

Do I need an end switch?

Yes if the valve has to start the boiler or circulator when it opens. Check whether the old valve had an end switch and match it.

Can I keep the valve body and change only the motor?

Yes on most models. See zone valve replacement heads.