Intatec ZERO14SW Heat Pump Anti-Freeze Valve – 1¼" Male × 1¼" Female Swivel
1¼" Male × 1¼" Female Swivel — Water-Sensing Thermostatic Anti-Freeze Valve — Part L Compliant
The Intatec ZERO14SW is a patented water-sensing thermostatic anti-freeze valve engineered to protect air source heat pump systems from freeze damage. Unlike ambient air-sensing valves, the Zero's wax thermostatic element sits directly in the water flow — it reacts to the actual system water temperature, not the surrounding air temperature. This means it operates correctly when fully insulated, in compliance with Building Regulations Part L, which requires all external heat pump pipework and fittings to be fully insulated and sealed.
The valve discharges when the water temperature drops to 3°C and closes again at 4°C, draining just enough water to prevent ice formation without unnecessary water loss. Sold individually; Inta recommend fitting one valve on both the flow and return pipework.
Independently Tested Insulation Performance
Inta independently tested the Zero valves at a controlled ambient temperature of -1°C to +1°C with a starting water temperature of 10°C:
Without Insulation
Discharge temperature: 2.49°C
Time to discharge: 1 hour 4 minutes
With Insulation ✓
Discharge temperature: 2.03°C
Time to discharge: 4 hours 3 minutes
Insulation delays discharge (giving more time for the system to respond) and results in a slightly lower discharge temperature — confirming the valve functions correctly and reliably when fully insulated.
Technical Specifications
| Parameter | Value |
|---|---|
| MPN / Product code | ZERO14SW |
| Inlet connection | G1¼" male BSP (inlet — to heat pump port or HPBV ball valve) |
| Outlet / discharge | G1¼" female swivel (outlet — to flexible hose or system pipe) + discharge port downward |
| Kv value | 52 m³/h |
| Max inlet pressure (static) | 10 Bar |
| Min inlet pressure | 0.5 Bar |
| Opening temperature | 3°C |
| Closing temperature | 4°C |
| Sensitivity | ±1°C |
| Working temperature range | 0°C to 80°C |
| Ambient temperature range | -30°C to 60°C |
| Max discharge flow rate @ 3 Bar | 1.5 L/h |
| Medium | Water |
| Dimensions | 74mm tall × 58mm wide (swivel body) |
| Thread standard | BS EN ISO 228 |
| Valve body material | Brass — BS EN 12165 CW617N |
| Spring | Stainless steel |
| Temperature element | Wax |
| Internal seals | EPDM peroxide |
| Internal parts | Brass — BS EN 12164 CW617N |
| R290 refrigerant compatible | Yes |
| Manufacturer | Intatec Ltd, Hixon, Staffordshire ST18 0PF |
Key Features
Water-sensing — not air-sensing
The wax thermostatic element sits directly in the water flow. The valve responds to actual system water temperature — not ambient air — so it operates accurately regardless of weather conditions, wind chill, or the insulation layer around the valve body.
Fully insulatable — Part L compliant
Building Regulations Part L requires all external ASHP fittings to be fully insulated. Because the Zero element sits in the water (not the air), the valve can be completely encased in insulation and sealed — maintaining system efficiency while still discharging reliably at 3°C.
Debris-resistant cartridge design
A protective ring around the thermostatic cartridge prevents system debris from settling into the operating mechanism. Double O-rings with reduced-friction surface treatment ensure correct valve operation and reliable sealing even after extended periods without activation.
Vacuum breaker with ZEROGUARD option
The built-in vacuum breaker prevents backflow contamination and must remain clear at all times. The optional ZEROGUARD cover (sold separately or as part of a ZG bundle) fits over the vacuum breaker, protecting it from debris, insects, and the elements while allowing air flow and annual inspection without disturbing the insulation.
Chamfered discharge edge
The discharge outlet has a chamfered edge that prevents water droplets forming and freezing at the tip — a subtle but important design detail that maintains free discharge even in sub-zero ambient temperatures.
Serviceable thermostatic cartridge
The thermostatic cartridge and vacuum breaker are both replaceable in the field using standard spanners (26mm A/F for cartridge, 20mm A/F for vacuum breaker), without removing the valve body from the pipework. Replacement parts available from Intatec.
Installation Requirements
The Zero valve must be installed outdoors, vertically, with the discharge port facing directly downward — never horizontal or inverted. Install as close to the heat pump as possible, on both flow and return pipes. Minimum 150mm clearance between the discharge port and the ground to prevent discharged water refreezing and blocking the outlet. If installing two valves on adjacent pipes, leave at least 100mm between them so discharge from the upper valve cannot fall onto the lower valve.
Flush all pipework thoroughly before installation. Do not allow debris, PTFE tape, or metal particles to enter the valve. Avoid installing near heat sources (boilers, flues) which could interfere with the thermostatic element. Avoid any upstream elbow that creates a water trap below the valve, which would prevent complete drainage.
Compatible Accessories (Intatec)
| Code | Description |
|---|---|
| ZEROGUARD | Anti-vacuum valve protector — two-part push-fit cover for the vacuum breaker |
| INSULZERO35SW | Pre-formed insulation jacket specifically for 1¼" swivel Zero valve (ZERO14SW) |
| INSULBOND | 290ml Bond & Seal — for sealing insulation joints around the valve |
| ZERO14SWZG | ZERO14SW pre-bundled with ZEROGUARD |
| HPBV35 | Heat pump extended key ball valve 1¼" × 35mm — installs between heat pump and ZERO14SW |
Frequently Asked Questions
How many ZERO14SW valves do I need?
Inta recommend fitting one valve on both the flow and return pipework — so a standard heat pump installation requires two ZERO14SW valves. The valve is sold individually; order two for a complete installation.
Does the ZERO14SW need to be insulated?
Building Regulations Part L requires all external heat pump pipework and fittings to be fully insulated. Use the INSULZERO35SW pre-formed insulation jacket (sold separately) with INSULBOND 290ml Bond & Seal to fully encapsulate the valve. Only the ZEROGUARD-protected vacuum breaker and the discharge port tip should remain exposed. Insulation must be inspected and resealed annually.
Why does the ZERO14SW have a ZEROGUARD version (ZERO14SWZG)?
The ZERO14SWZG is simply the ZERO14SW supplied pre-paired with a ZEROGUARD vacuum breaker cover. Inta recommend always using a ZEROGUARD, so the ZG bundle saves a separate order and ensures the correct cover is to hand at installation. The cover can also be purchased separately if you already have the valve.
What does the vacuum breaker do and can it be serviced?
The vacuum breaker (anti-vacuum valve) prevents a negative pressure siphon from drawing contaminated water back into the system after discharge. It must remain clear and unobstructed at all times. It can be removed for inspection or replacement using a 20mm A/F spanner — without removing the valve body from the pipework. The plastic vacuum cap should fall free when the body is inverted; if it does not, the vacuum breaker needs replacing.
Can the thermostatic cartridge be replaced on site?
Yes — using a 26mm A/F spanner to unscrew the cartridge from the valve body. Only fit genuine Inta replacement cartridges. If the valve keeps discharging without the water temperature dropping to 3°C, check that the valve is not located near a heat source, that the vacuum breaker is not blocked, and that insulation has not been applied incorrectly. If the fault persists, replace the cartridge.
Intatec ZERO1SW Anti-Freeze Valve 1" swivel companion for 28mm / smaller port systems | Intatec ZEROGUARD Anti-Vacuum Valve Protector | INSULZERO35SW Insulation Jacket | INSULBOND 290ml Bond & Seal | Intatec HPBV35 Heat Pump Ball Valve | Intatec IntaKlean HP Magnetic Filter
Original: $221.35
-65%$221.35
$77.47More Images
Intatec ZERO14SW Heat Pump Anti-Freeze Valve – 1¼" Male × 1¼" Female Swivel
1¼" Male × 1¼" Female Swivel — Water-Sensing Thermostatic Anti-Freeze Valve — Part L Compliant
The Intatec ZERO14SW is a patented water-sensing thermostatic anti-freeze valve engineered to protect air source heat pump systems from freeze damage. Unlike ambient air-sensing valves, the Zero's wax thermostatic element sits directly in the water flow — it reacts to the actual system water temperature, not the surrounding air temperature. This means it operates correctly when fully insulated, in compliance with Building Regulations Part L, which requires all external heat pump pipework and fittings to be fully insulated and sealed.
The valve discharges when the water temperature drops to 3°C and closes again at 4°C, draining just enough water to prevent ice formation without unnecessary water loss. Sold individually; Inta recommend fitting one valve on both the flow and return pipework.
Independently Tested Insulation Performance
Inta independently tested the Zero valves at a controlled ambient temperature of -1°C to +1°C with a starting water temperature of 10°C:
Without Insulation
Discharge temperature: 2.49°C
Time to discharge: 1 hour 4 minutes
With Insulation ✓
Discharge temperature: 2.03°C
Time to discharge: 4 hours 3 minutes
Insulation delays discharge (giving more time for the system to respond) and results in a slightly lower discharge temperature — confirming the valve functions correctly and reliably when fully insulated.
Technical Specifications
| Parameter | Value |
|---|---|
| MPN / Product code | ZERO14SW |
| Inlet connection | G1¼" male BSP (inlet — to heat pump port or HPBV ball valve) |
| Outlet / discharge | G1¼" female swivel (outlet — to flexible hose or system pipe) + discharge port downward |
| Kv value | 52 m³/h |
| Max inlet pressure (static) | 10 Bar |
| Min inlet pressure | 0.5 Bar |
| Opening temperature | 3°C |
| Closing temperature | 4°C |
| Sensitivity | ±1°C |
| Working temperature range | 0°C to 80°C |
| Ambient temperature range | -30°C to 60°C |
| Max discharge flow rate @ 3 Bar | 1.5 L/h |
| Medium | Water |
| Dimensions | 74mm tall × 58mm wide (swivel body) |
| Thread standard | BS EN ISO 228 |
| Valve body material | Brass — BS EN 12165 CW617N |
| Spring | Stainless steel |
| Temperature element | Wax |
| Internal seals | EPDM peroxide |
| Internal parts | Brass — BS EN 12164 CW617N |
| R290 refrigerant compatible | Yes |
| Manufacturer | Intatec Ltd, Hixon, Staffordshire ST18 0PF |
Key Features
Water-sensing — not air-sensing
The wax thermostatic element sits directly in the water flow. The valve responds to actual system water temperature — not ambient air — so it operates accurately regardless of weather conditions, wind chill, or the insulation layer around the valve body.
Fully insulatable — Part L compliant
Building Regulations Part L requires all external ASHP fittings to be fully insulated. Because the Zero element sits in the water (not the air), the valve can be completely encased in insulation and sealed — maintaining system efficiency while still discharging reliably at 3°C.
Debris-resistant cartridge design
A protective ring around the thermostatic cartridge prevents system debris from settling into the operating mechanism. Double O-rings with reduced-friction surface treatment ensure correct valve operation and reliable sealing even after extended periods without activation.
Vacuum breaker with ZEROGUARD option
The built-in vacuum breaker prevents backflow contamination and must remain clear at all times. The optional ZEROGUARD cover (sold separately or as part of a ZG bundle) fits over the vacuum breaker, protecting it from debris, insects, and the elements while allowing air flow and annual inspection without disturbing the insulation.
Chamfered discharge edge
The discharge outlet has a chamfered edge that prevents water droplets forming and freezing at the tip — a subtle but important design detail that maintains free discharge even in sub-zero ambient temperatures.
Serviceable thermostatic cartridge
The thermostatic cartridge and vacuum breaker are both replaceable in the field using standard spanners (26mm A/F for cartridge, 20mm A/F for vacuum breaker), without removing the valve body from the pipework. Replacement parts available from Intatec.
Installation Requirements
The Zero valve must be installed outdoors, vertically, with the discharge port facing directly downward — never horizontal or inverted. Install as close to the heat pump as possible, on both flow and return pipes. Minimum 150mm clearance between the discharge port and the ground to prevent discharged water refreezing and blocking the outlet. If installing two valves on adjacent pipes, leave at least 100mm between them so discharge from the upper valve cannot fall onto the lower valve.
Flush all pipework thoroughly before installation. Do not allow debris, PTFE tape, or metal particles to enter the valve. Avoid installing near heat sources (boilers, flues) which could interfere with the thermostatic element. Avoid any upstream elbow that creates a water trap below the valve, which would prevent complete drainage.
Compatible Accessories (Intatec)
| Code | Description |
|---|---|
| ZEROGUARD | Anti-vacuum valve protector — two-part push-fit cover for the vacuum breaker |
| INSULZERO35SW | Pre-formed insulation jacket specifically for 1¼" swivel Zero valve (ZERO14SW) |
| INSULBOND | 290ml Bond & Seal — for sealing insulation joints around the valve |
| ZERO14SWZG | ZERO14SW pre-bundled with ZEROGUARD |
| HPBV35 | Heat pump extended key ball valve 1¼" × 35mm — installs between heat pump and ZERO14SW |
Frequently Asked Questions
How many ZERO14SW valves do I need?
Inta recommend fitting one valve on both the flow and return pipework — so a standard heat pump installation requires two ZERO14SW valves. The valve is sold individually; order two for a complete installation.
Does the ZERO14SW need to be insulated?
Building Regulations Part L requires all external heat pump pipework and fittings to be fully insulated. Use the INSULZERO35SW pre-formed insulation jacket (sold separately) with INSULBOND 290ml Bond & Seal to fully encapsulate the valve. Only the ZEROGUARD-protected vacuum breaker and the discharge port tip should remain exposed. Insulation must be inspected and resealed annually.
Why does the ZERO14SW have a ZEROGUARD version (ZERO14SWZG)?
The ZERO14SWZG is simply the ZERO14SW supplied pre-paired with a ZEROGUARD vacuum breaker cover. Inta recommend always using a ZEROGUARD, so the ZG bundle saves a separate order and ensures the correct cover is to hand at installation. The cover can also be purchased separately if you already have the valve.
What does the vacuum breaker do and can it be serviced?
The vacuum breaker (anti-vacuum valve) prevents a negative pressure siphon from drawing contaminated water back into the system after discharge. It must remain clear and unobstructed at all times. It can be removed for inspection or replacement using a 20mm A/F spanner — without removing the valve body from the pipework. The plastic vacuum cap should fall free when the body is inverted; if it does not, the vacuum breaker needs replacing.
Can the thermostatic cartridge be replaced on site?
Yes — using a 26mm A/F spanner to unscrew the cartridge from the valve body. Only fit genuine Inta replacement cartridges. If the valve keeps discharging without the water temperature dropping to 3°C, check that the valve is not located near a heat source, that the vacuum breaker is not blocked, and that insulation has not been applied incorrectly. If the fault persists, replace the cartridge.
Intatec ZERO1SW Anti-Freeze Valve 1" swivel companion for 28mm / smaller port systems | Intatec ZEROGUARD Anti-Vacuum Valve Protector | INSULZERO35SW Insulation Jacket | INSULBOND 290ml Bond & Seal | Intatec HPBV35 Heat Pump Ball Valve | Intatec IntaKlean HP Magnetic Filter
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
1¼" Male × 1¼" Female Swivel — Water-Sensing Thermostatic Anti-Freeze Valve — Part L Compliant
The Intatec ZERO14SW is a patented water-sensing thermostatic anti-freeze valve engineered to protect air source heat pump systems from freeze damage. Unlike ambient air-sensing valves, the Zero's wax thermostatic element sits directly in the water flow — it reacts to the actual system water temperature, not the surrounding air temperature. This means it operates correctly when fully insulated, in compliance with Building Regulations Part L, which requires all external heat pump pipework and fittings to be fully insulated and sealed.
The valve discharges when the water temperature drops to 3°C and closes again at 4°C, draining just enough water to prevent ice formation without unnecessary water loss. Sold individually; Inta recommend fitting one valve on both the flow and return pipework.
Independently Tested Insulation Performance
Inta independently tested the Zero valves at a controlled ambient temperature of -1°C to +1°C with a starting water temperature of 10°C:
Without Insulation
Discharge temperature: 2.49°C
Time to discharge: 1 hour 4 minutes
With Insulation ✓
Discharge temperature: 2.03°C
Time to discharge: 4 hours 3 minutes
Insulation delays discharge (giving more time for the system to respond) and results in a slightly lower discharge temperature — confirming the valve functions correctly and reliably when fully insulated.
Technical Specifications
| Parameter | Value |
|---|---|
| MPN / Product code | ZERO14SW |
| Inlet connection | G1¼" male BSP (inlet — to heat pump port or HPBV ball valve) |
| Outlet / discharge | G1¼" female swivel (outlet — to flexible hose or system pipe) + discharge port downward |
| Kv value | 52 m³/h |
| Max inlet pressure (static) | 10 Bar |
| Min inlet pressure | 0.5 Bar |
| Opening temperature | 3°C |
| Closing temperature | 4°C |
| Sensitivity | ±1°C |
| Working temperature range | 0°C to 80°C |
| Ambient temperature range | -30°C to 60°C |
| Max discharge flow rate @ 3 Bar | 1.5 L/h |
| Medium | Water |
| Dimensions | 74mm tall × 58mm wide (swivel body) |
| Thread standard | BS EN ISO 228 |
| Valve body material | Brass — BS EN 12165 CW617N |
| Spring | Stainless steel |
| Temperature element | Wax |
| Internal seals | EPDM peroxide |
| Internal parts | Brass — BS EN 12164 CW617N |
| R290 refrigerant compatible | Yes |
| Manufacturer | Intatec Ltd, Hixon, Staffordshire ST18 0PF |
Key Features
Water-sensing — not air-sensing
The wax thermostatic element sits directly in the water flow. The valve responds to actual system water temperature — not ambient air — so it operates accurately regardless of weather conditions, wind chill, or the insulation layer around the valve body.
Fully insulatable — Part L compliant
Building Regulations Part L requires all external ASHP fittings to be fully insulated. Because the Zero element sits in the water (not the air), the valve can be completely encased in insulation and sealed — maintaining system efficiency while still discharging reliably at 3°C.
Debris-resistant cartridge design
A protective ring around the thermostatic cartridge prevents system debris from settling into the operating mechanism. Double O-rings with reduced-friction surface treatment ensure correct valve operation and reliable sealing even after extended periods without activation.
Vacuum breaker with ZEROGUARD option
The built-in vacuum breaker prevents backflow contamination and must remain clear at all times. The optional ZEROGUARD cover (sold separately or as part of a ZG bundle) fits over the vacuum breaker, protecting it from debris, insects, and the elements while allowing air flow and annual inspection without disturbing the insulation.
Chamfered discharge edge
The discharge outlet has a chamfered edge that prevents water droplets forming and freezing at the tip — a subtle but important design detail that maintains free discharge even in sub-zero ambient temperatures.
Serviceable thermostatic cartridge
The thermostatic cartridge and vacuum breaker are both replaceable in the field using standard spanners (26mm A/F for cartridge, 20mm A/F for vacuum breaker), without removing the valve body from the pipework. Replacement parts available from Intatec.
Installation Requirements
The Zero valve must be installed outdoors, vertically, with the discharge port facing directly downward — never horizontal or inverted. Install as close to the heat pump as possible, on both flow and return pipes. Minimum 150mm clearance between the discharge port and the ground to prevent discharged water refreezing and blocking the outlet. If installing two valves on adjacent pipes, leave at least 100mm between them so discharge from the upper valve cannot fall onto the lower valve.
Flush all pipework thoroughly before installation. Do not allow debris, PTFE tape, or metal particles to enter the valve. Avoid installing near heat sources (boilers, flues) which could interfere with the thermostatic element. Avoid any upstream elbow that creates a water trap below the valve, which would prevent complete drainage.
Compatible Accessories (Intatec)
| Code | Description |
|---|---|
| ZEROGUARD | Anti-vacuum valve protector — two-part push-fit cover for the vacuum breaker |
| INSULZERO35SW | Pre-formed insulation jacket specifically for 1¼" swivel Zero valve (ZERO14SW) |
| INSULBOND | 290ml Bond & Seal — for sealing insulation joints around the valve |
| ZERO14SWZG | ZERO14SW pre-bundled with ZEROGUARD |
| HPBV35 | Heat pump extended key ball valve 1¼" × 35mm — installs between heat pump and ZERO14SW |
Frequently Asked Questions
How many ZERO14SW valves do I need?
Inta recommend fitting one valve on both the flow and return pipework — so a standard heat pump installation requires two ZERO14SW valves. The valve is sold individually; order two for a complete installation.
Does the ZERO14SW need to be insulated?
Building Regulations Part L requires all external heat pump pipework and fittings to be fully insulated. Use the INSULZERO35SW pre-formed insulation jacket (sold separately) with INSULBOND 290ml Bond & Seal to fully encapsulate the valve. Only the ZEROGUARD-protected vacuum breaker and the discharge port tip should remain exposed. Insulation must be inspected and resealed annually.
Why does the ZERO14SW have a ZEROGUARD version (ZERO14SWZG)?
The ZERO14SWZG is simply the ZERO14SW supplied pre-paired with a ZEROGUARD vacuum breaker cover. Inta recommend always using a ZEROGUARD, so the ZG bundle saves a separate order and ensures the correct cover is to hand at installation. The cover can also be purchased separately if you already have the valve.
What does the vacuum breaker do and can it be serviced?
The vacuum breaker (anti-vacuum valve) prevents a negative pressure siphon from drawing contaminated water back into the system after discharge. It must remain clear and unobstructed at all times. It can be removed for inspection or replacement using a 20mm A/F spanner — without removing the valve body from the pipework. The plastic vacuum cap should fall free when the body is inverted; if it does not, the vacuum breaker needs replacing.
Can the thermostatic cartridge be replaced on site?
Yes — using a 26mm A/F spanner to unscrew the cartridge from the valve body. Only fit genuine Inta replacement cartridges. If the valve keeps discharging without the water temperature dropping to 3°C, check that the valve is not located near a heat source, that the vacuum breaker is not blocked, and that insulation has not been applied incorrectly. If the fault persists, replace the cartridge.
Intatec ZERO1SW Anti-Freeze Valve 1" swivel companion for 28mm / smaller port systems | Intatec ZEROGUARD Anti-Vacuum Valve Protector | INSULZERO35SW Insulation Jacket | INSULBOND 290ml Bond & Seal | Intatec HPBV35 Heat Pump Ball Valve | Intatec IntaKlean HP Magnetic Filter
