The bypass valve on underfloor heating is manually adjustable, typically ranging from 0.05 Bar to 0.5 Bar. A setting between 0.2 Bar and 0.3 Bar is generally sufficient for most common underfloor heating installations.
Here's a breakdown of what you need to know:
- Adjustment Range: The valve allows for a pressure differential setting from 0.05 Bar to 0.5 Bar.
- Typical Setting: For the majority of residential underfloor heating systems, a setting between 0.2 Bar and 0.3 Bar is appropriate.
- Flow Curves: Manufacturers often provide flow curves showing the performance of the bypass valve at different settings (e.g., 0.1, 0.2, 0.3, 0.4, and 0.5 Bar). Consult these curves during setup and troubleshooting.
The bypass valve ensures that the system maintains adequate flow when thermostatic radiator valves (TRVs) close down zones, preventing the pump from working against a dead head. Improperly setting the bypass valve can lead to issues like:
- Insufficient Flow: If the setting is too high, the pump may struggle to provide adequate flow to all zones.
- Excessive Flow: If the setting is too low, the bypass may open too frequently, causing short cycling or uneven heating.
Important Considerations:
- System Design: The optimal setting for the bypass valve depends on the specific design of your underfloor heating system, including pipe lengths, number of zones, and pump capacity.
- Professional Advice: If you are unsure about the correct setting, consult a qualified heating engineer. They can assess your system and recommend the most appropriate setting for optimal performance.
- Manufacturer's Instructions: Always refer to the underfloor heating system manufacturer's instructions for specific guidance on setting the bypass valve.
