1¼″ Male x Female Swivel ASHP Antifreeze Valve
The 1¼″ Male x Female Swivel ASHP Antifreeze Valve provides automatic frost protection for suitable water-based heat pump systems. It opens when system water falls to approximately 3°C and closes again at approximately 4°C. In addition, the female swivel connection makes installation easier around fixed heat pump components and external pipework.
Automatic ASHP Frost Protection
Outdoor heat pump pipework can become vulnerable during freezing weather.
If circulation stops during a power cut or system fault, water inside the exposed circuit may begin to freeze.
The antifreeze valve responds automatically when water temperature approaches freezing.
Therefore, it helps reduce the risk of damage to the heat pump and associated pipework.
1¼″ Male x 1¼″ Female Swivel Connections
This version combines:
- 1¼″ male connection
- 1¼″ female swivel connection
The swivel connection provides additional flexibility during installation.
Instead of rotating the complete valve or adjoining component, the installer can tighten the swivel independently.
This can make connections around the heat pump faster and neater.
Exact Product Code ZL-7201-11/4MF
The manufacturer product code is:
ZL-7201-11/4MF
This identifies the 1¼″ male x female swivel version within the Bastion antifreeze-valve range.
Using the exact code also helps engineers identify the correct replacement component during service work.
Designed for Air Source Heat Pumps
The valve suits compatible water-based air source heat pump systems.
Typical applications include:
- Air source heat pumps
- Monobloc heat pumps
- 1¼″ ASHP pipework
- Heat pump flow circuits
- Heat pump return circuits
- External heating pipework
- Renewable heating systems
- Heat pump servicing
- ASHP replacement work
- New heat pump installations
Always follow the heat pump manufacturer’s frost-protection requirements.
Opens Automatically at 3°C
The temperature-sensitive mechanism monitors the water passing through the valve.
When the water reaches approximately 3°C, the valve opens.
This allows system water to discharge before freezing occurs.
As a result, the valve provides automatic protection without relying on electronic controls.
Closes Automatically at 4°C
Once the system water temperature increases to approximately 4°C, the valve closes again.
Therefore, normal operation can resume automatically.
The published temperature sensitivity is ±1°C.
No Electrical Supply Required
The antifreeze valve works mechanically.
Therefore, it does not need:
- Electricity
- Batteries
- Wi-Fi
- External temperature sensors
- Control wiring
- A thermostat
This is particularly useful during power failures, when electrically powered frost protection may no longer operate.
Ideal for Monobloc Heat Pumps
Monobloc heat pumps contain part of the water circuit outside the building.
Therefore, the flow and return pipework near the unit can become exposed to low temperatures.
Mechanical antifreeze valves provide an additional frost-protection method where approved by the heat pump manufacturer.
Female Swivel Makes Installation Easier
The swivel connection is particularly useful around fixed equipment.
For example, installers may need to connect:
- Heat pump outlets
- Extended ball valves
- Flexible hoses
- Antifreeze valves
- Isolation valves
- External insulated pipework
The female swivel helps align components without rotating the entire assembly.
Therefore, it can reduce stress on adjoining connections.
Suitable for Water-Based Systems
The Bastion antifreeze valve is designed for water-based heating systems.
If the heating circuit contains glycol, always check the heat pump manufacturer’s frost-protection design before fitting an antifreeze valve.
Different systems can use different protection methods.
10 Bar Maximum Inlet Pressure
The published maximum static inlet pressure is 10 bar.
Therefore, the valve covers the operating pressures found in many domestic and light-commercial heat pump systems.
Always confirm the complete hydraulic design before installation.
0°C to 65°C Working Range
The published system-water temperature range is:
0°C to 65°C
The ambient operating range is:
-30°C to 60°C.
This makes the valve suitable for exposed outdoor heating installations where freezing conditions may occur.
High-Flow Design
The published Kv value for the Bastion antifreeze valve range is 55m³/h.
Therefore, the valve provides a high-flow connection for suitable heat pump circuits.
However, the full heating system must still be sized according to the heat pump manufacturer’s hydraulic requirements.
Suitable for Flow and Return Pipework
Many water-based ASHP installations use antifreeze protection on both the flow and return.
This helps protect the complete external circuit.
However, the exact arrangement depends on the heat pump manufacturer and system design.
Therefore, always follow the installation instructions supplied with the heat pump.
Where Should the Antifreeze Valve Be Installed?
The valve normally sits within the exposed heat pump pipework.
Position it where:
- It can sense system water temperature correctly
- Discharged water can escape safely
- The outlet remains unobstructed
- The valve remains accessible
- The installation follows the heat pump manufacturer’s guidance
Avoid locations where discharged water could cause a hazard.
Keep the Discharge Outlet Clear
The valve protects the system by releasing water.
Therefore, never block or cap the discharge outlet.
Also consider where discharged water may freeze once it leaves the valve.
A suitable installation should prevent ice from creating a slip hazard or blocking the discharge path.
Antifreeze Valve vs Glycol
Some ASHP systems use antifreeze valves.
Others use glycol-based heat-transfer fluid.
The correct method depends on:
- Heat pump manufacturer
- System design
- Outdoor pipework
- Local climate
- Water-treatment requirements
- Installer specification
Therefore, never remove glycol or change the frost-protection method without checking the system specification.
Ideal for Replacement and Service Work
Antifreeze valves may need replacement during the life of the heating system.
Typical reasons include:
- Leakage
- Valve damage
- Cartridge failure
- Frost damage
- System alterations
- Heat pump replacement
- Pipework upgrades
- Component servicing
The ZL-7201-11/4MF provides a direct replacement option where compatible 1¼″ male and female swivel connections are required.
Part of the Expanded Kudos Antifreeze Valve Range
Kudos Trading stocks a growing range of antifreeze valves for professional heat pump installers.
Connection options include:
- 28mm compression
- 1″ male
- 1¼″ male x female swivel
- Additional heat pump connection options
Therefore, installers can select the connection type that best matches the existing system.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | Kudos Trading |
| Product | ASHP Antifreeze Valve |
| Product Code | ZL-7201-11/4MF |
| Connection Size | 1¼″ |
| Inlet Connection | 1¼″ Male |
| Outlet Connection | 1¼″ Female Swivel |
| Medium | Water |
| Maximum Inlet Pressure | 10 Bar |
| Working Temperature Range | 0°C to 65°C |
| Ambient Temperature Range | -30°C to 60°C |
| Opening Temperature | 3°C |
| Closing Temperature | 4°C |
| Sensitivity | ±1°C |
| Kv Value | 55m³/h |
| Electrical Supply | Not Required |
| Application | Air Source Heat Pump Systems |
| Manufacturer Warranty | 2 Years |
Published Bastion data confirms the product code, operating temperatures, pressure, sensitivity and two-year guarantee for the antifreeze-valve range.
Why Choose a Male x Female Swivel Antifreeze Valve?
Key benefits include:
- Automatic frost protection
- 1¼″ male connection
- 1¼″ female swivel connection
- Easier installation around fixed equipment
- Opens at approximately 3°C
- Closes automatically at approximately 4°C
- No electrical power required
- No batteries required
- 10 bar maximum inlet pressure
- High-flow design
- Suitable for compatible monobloc heat pumps
- Ideal for replacement work
- Suitable for external pipework
- Two-year manufacturer guarantee
Why Buy From Kudos Trading?
Kudos Trading supplies professional heat pump, heating and plumbing components throughout the UK.
Our expanding air source heat pump range includes antifreeze valves, flexible hoses, balancing valves, filters, flow setters and air separators.
Therefore, installers can source more ASHP replacement and service components from one supplier.
We have supplied underfloor heating products to the UK since 2001.
Frequently Asked Questions
What Size Connections Does This Antifreeze Valve Have?
The valve has a 1¼″ male connection on one side and a 1¼″ female swivel connection on the other.
What Is the Product Code?
The product code is ZL-7201-11/4MF.
Why Does the Valve Have a Female Swivel?
The female swivel makes installation easier around fixed pipework and heat pump equipment.
It allows the joint to tighten without rotating the complete valve.
At What Temperature Does the Valve Open?
The valve opens at approximately 3°C.
At What Temperature Does It Close?
It closes again at approximately 4°C.
Does It Need Electricity?
No.
The valve operates mechanically and requires no electrical supply.
Is It Suitable for a Monobloc Heat Pump?
Yes, where the heat pump manufacturer allows mechanical antifreeze valves within the frost-protection strategy.
Should I Fit One on the Flow and Return?
Many ASHP systems use protection on both exposed flow and return pipework.
However, always follow the specific heat pump manufacturer’s installation instructions.
Can I Use It with Glycol?
This valve is designed for water-based systems.
If glycol is present, check the heat pump manufacturer’s requirements before installation.
What Is the Maximum Working Pressure?
The published maximum inlet pressure is 10 bar.
What Is the Working Temperature Range?
The published water temperature range is 0°C to 65°C.
The ambient range is -30°C to 60°C.
What Is the Kv Value?
The published Kv value is 55m³/h.
Is a 28mm Version Available?
Yes.
Kudos Trading also stocks the 28mm ASHP Antifreeze Valve.
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