The Belimo ZONE220S-50+ZONE120NC-S is a 3/4 in. (DN 20) 2-way on/off zone valve assembly: a ZONE220S-50 forged brass valve with sweat ends, Cv 5 and 25 psi close-off, paired with a ZONE120NC-S AC 120 V normally closed spring return actuator for fail-safe operation on 2-wire control. The -S actuator adds one built-in SPST auxiliary switch rated 5 A resistive (5 A inductive) at AC 120 V.
Best For
- Fan coil units
- Baseboard heating
- Other hydronic zone applications where fail-safe operation on 2-wire control is required
- Hydronic systems with variable or constant flow
- Compact installations that need on/off zone control
- On/off control from a thermostat or controller switching AC 120 V
Warranty
Belimo 2-year warranty on the ZONE220S-50+ZONE120NC-S.
Key Features
Spring Return Fail-Safe
Normally Closed spring return actuator for fail-safe operation on 2-wire on/off control.
Forged Brass Body
Forged brass body, EPDM seat and housing seal, and stainless steel stem. 300 psi body pressure rating.
Cv 5, 25 psi Close-Off
On/off flow characteristic, Cv 5, 25 psi close-off pressure and ANSI Class III 0.1% leakage.
Sweat Connections
3/4 in. (DN 20) sweat ends for chilled or hot water, up to 50% glycol, at 32...212°F [0...100°C].
Built-In Auxiliary Switch
One built-in 1 x SPST auxiliary switch rated 5 A resistive (5 A inductive) @ AC 120 V, wired on red leads to the auxiliary circuit.
Manual Override
Hand lever manual override and integrated mechanical position indication.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
| Valve: ZONE220S-50 | |
| Valve Size | 3/4 in. (0.75 in.), DN 20 |
|---|---|
| Flow Pattern | 2-way |
| Flow Characteristic | on/off |
| Cv | 5 |
| Close-Off Pressure | 25 psi |
| Body Pressure Rating | 300 psi |
| Leakage Rate | ANSI Class III 0.1% |
| Fluid | chilled or hot water, up to 50% glycol |
| Fluid Temperature Range (Water) | 32...212°F [0...100°C] |
| Pipe Connection | Sweat |
| Valve Body | forged brass |
| Housing Seal | EPDM |
| Stem | stainless steel |
| Seat | EPDM |
| Suitable Actuators | Belimo ZONE spring return |
| Actuator: ZONE120NC-S | |
| Nominal Voltage | AC 120 V |
| Nominal Voltage Frequency | 50/60 Hz |
| Power Consumption in Operation | 6.5 W |
| Transformer Sizing | 7 VA |
| Control | On/off, 2-wire |
| Normal Position | Normally Closed (NC) |
| Auxiliary Switch | 1 x SPST, 5 A resistive (5 A inductive) @ AC 120 V |
| Electrical Connection | 6 in. wire leads |
| Manual Override | hand lever |
| Angle of Rotation | 90° |
| Noise Level, Motor | 35 dB(A) |
| Noise Level, Fail-Safe | 35 dB(A) |
| Position Indication | Mechanically (integrated) |
| Degree of Protection IEC/EN | IP20 |
| Degree of Protection NEMA/UL | NEMA 1 |
| Enclosure | UL Enclosure Type 1 |
| Agency Listing | CE, cULus |
| Quality Standard | ISO 9001 |
| Ambient Temperature | 32...104°F [0...40°C] |
| Storage Temperature | -40...176°F [-40...80°C] |
| Ambient Humidity | Max. 95% RH, non-condensing |
| Servicing | maintenance-free |
| Housing Material | galvanized steel |
Specifications sourced from the Belimo ZONE220S-50+ZONE120NC-S technical data sheet (2022-01-12 edition). Reviewed October 10, 2026.
Documentation
Technical Data Sheet: Belimo ZONE220S-50+ZONE120NC-SInstallation Instructions: ZONE Series Zone ValvesFAQ
What is the Cv of the Belimo ZONE220S-50+ZONE120NC-S?
The ZONE220S-50 valve in the Belimo ZONE220S-50+ZONE120NC-S has a Cv of 5 and a close-off pressure of 25 psi. It is a 3/4 in. 2-way valve with an on/off flow characteristic.
What pipe connection does the Belimo ZONE220S-50+ZONE120NC-S have?
The Belimo ZONE220S-50+ZONE120NC-S has 3/4 in. sweat pipe connections on a forged brass valve body.
What fluids and temperatures can the Belimo ZONE220S-50+ZONE120NC-S handle?
It is rated for chilled or hot water, up to 50% glycol, with a fluid temperature range of 32...212°F [0...100°C] and a 300 psi body pressure rating.
What voltage does the ZONE120NC-S actuator on the Belimo ZONE220S-50+ZONE120NC-S use?
The ZONE120NC-S runs on AC 120 V, 50/60 Hz. It draws 6.5 W in operation; size the transformer at 7 VA.
Is the Belimo ZONE220S-50+ZONE120NC-S normally open or normally closed?
The Belimo ZONE220S-50+ZONE120NC-S uses the ZONE120NC-S, the normally closed (NC) version of the Belimo ZONE spring return actuator, for on/off control on 2 wires.
Does the Belimo ZONE220S-50+ZONE120NC-S have an auxiliary switch?
Yes. The ZONE120NC-S has one built-in 1 x SPST auxiliary switch rated 5 A resistive (5 A inductive) @ AC 120 V, wired on red leads.
Does the Belimo ZONE220S-50+ZONE120NC-S have a manual override?
Yes. The ZONE120NC-S actuator has a hand lever manual override and integrated mechanical position indication.
What wiring connection does the ZONE120NC-S have?
The ZONE120NC-S has 6 in. wire leads.
What is the warranty on the Belimo ZONE220S-50+ZONE120NC-S?
Belimo covers the ZONE220S-50+ZONE120NC-S with a 2-year warranty.
- Valve Pattern:
- 2-Way
- Valve Size:
- 3/4 Inch
- Connection Type:
- Sweat
- CV Rating:
- 5.0
- Max Close-Off Pressure:
- 25 psi
- Max Operating Pressure:
- 300 psi
- Medium Temperature Range:
- 32-212 °F
- Body Material:
- Forged Brass
- Actuator Type:
- Fail-Safe
- Fail-Safe Position:
- Fail Closed
- Voltage:
- 120VAC
- Control Signal:
- On/Off
- Auxillary Switch:
- (1) SPST 5A @ 120VAC
- Power Connection:
- Wire Leads
