Description
28mm Anti-Freeze Valve – Automatic ASHP Frost Protection
Protect your air source heat pump installation against freezing temperatures with the Bastion 28mm Anti-Freeze Valve
Designed for water-based heat pump systems, this automatic frost protection valve helps reduce the risk of freezing in exposed pipework, particularly during cold weather, power failures or interruptions to water circulation.
When the system water temperature falls to approximately 3°C, the valve automatically opens to discharge water from the circuit, helping prevent ice formation and potential damage to the heat pump and connected pipework.
Once the water temperature rises to approximately 4°C, the valve closes automatically.
Key Features & Benefits
- Automatic Frost Protection – Opens at approximately 3°C to help prevent freezing.
- 28mm Compression Connections – Suitable for compatible 28mm heating pipework.
- Ideal for ASHP Systems – Designed for water-based air source heat pump installations.
- Monobloc Heat Pump Compatible – Helps protect exposed external heating circuits.
- Automatic Operation – No electrical supply required for temperature-activated operation.
- Durable Brass Body – Manufactured for reliable performance in heating installations.
- 10 Bar Maximum Working Pressure – Suitable for compatible pressurised heating systems.
- Easy System Integration – Suitable for new installations, upgrades and replacement projects.
Technical Specifications
| Specification | Details |
|---|---|
| Brand | Bastion |
| Product Code | ZL-7201-28MM |
| Product Type | Automatic Anti-Freeze Valve |
| Connection Size | 28mm |
| Connection Type | Compression |
| Body Material | Brass CW617N |
| Seals | EPDM |
| Suitable Medium | Water |
| Opening Temperature | 3°C |
| Closing Temperature | 4°C |
| Temperature Accuracy | ±1°C |
| Maximum Working Pressure | 10 Bar |
| Working Temperature Range | 0°C to 65°C |
| Ambient Temperature Range | -30°C to +60°C |
| Application | ASHP Frost Protection |
Suitable Applications
- Air Source Heat Pumps (ASHP)
- Monobloc Heat Pump Systems
- External Heat Pump Flow and Return Pipework
- Water-Based Renewable Heating Systems
- New Heat Pump Installations
- Heating System Upgrades and Replacements
Why Install an Anti-Freeze Valve?
Air source heat pumps often have water-filled pipework located outside the property. During freezing conditions, particularly if the power supply fails or circulation stops, the water inside these pipes may freeze.
The Bastion 28mm Anti-Freeze Valve provides an automatic mechanical safeguard by releasing water when the circuit temperature approaches freezing.
Correctly installed antifreeze valves can help reduce the risk of frozen pipework and expensive damage to heat pump components.
Installation Information
The valve should be installed in accordance with the manufacturer’s instructions and the heat pump system design.
- Install in the correct orientation with the discharge outlet facing downwards.
- Ensure discharged water can drain safely and the outlet remains unobstructed.
- Follow the heat pump manufacturer’s requirements for valve positioning and frost protection.
- Check system compatibility before installation.
Important: This valve is designed for compatible water-based systems. It should not be assumed to replace glycol protection in every installation. Always follow the heat pump manufacturer’s recommendations.
