C15
Bosch EasyControl Underfloor Heating Control Configuration Fault

Bosch EasyControl displays error C15 and fails to control underfloor heating circuits correctly (overheating or underheating).

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Incorrect flow temperature limits set in EasyControl, Misconfigured mixing valve or pump control, Missing floor temperature sensor, Incompatible underfloor manifold actuators

How to Fix / Troubleshooting

Safety first: Turn off power to the boiler and any underfloor heating pumps or manifolds before working on wiring.

  • 1. Verify system type: In EasyControl installer settings, ensure the heating circuit is set to underfloor heating if applicable, with appropriate maximum flow temperature.
  • 2. Check floor sensor: If a floor temperature sensor is used, verify that it is connected correctly to the underfloor controller or boiler and that its cable is intact.
  • 3. Inspect manifold actuators: Confirm that Bosch-compatible or correctly rated 230 V/24 V actuators are installed and wired to the correct zone outputs.
  • 4. Adjust curves: Fine-tune the heating curve and maximum flow temperature in EasyControl to prevent overheating of floors.

Professional help: Underfloor systems are complex; if C15 persists, a heating engineer should review the hydraulic and control design.

Advertisements

Repair Difficulty

Hard 4/5

Required Part

Underfloor heating manifold actuators
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements