A15
Riello Blocked or Frozen Condensate Drain

Boiler shows condensate fault, often during cold weather, boiler will not fire

Advertisements

Possible Causes

Frozen external condensate pipe, Blocked condensate trap, Incorrectly sized or sloped condensate pipework, Debris in trap

How to Fix / Troubleshooting

Safety: Condensate is mildly acidic. Wear gloves and eye protection when handling. Isolate power before removing the trap.

  • Check external pipe: Inspect the external condensate pipe for ice. If frozen, pour warm (not boiling) water over the pipe to thaw. Insulate the pipe to prevent recurrence.
  • Empty and clean trap: Remove the condensate trap beneath the boiler, empty it into a suitable container, and rinse out any debris. Refit securely, ensuring seals are in place.
  • Check pipe fall: Ensure the condensate pipe slopes continuously downward with no sags that can trap water.
  • Reset boiler: After clearing the blockage, reset the boiler and confirm normal operation.
Advertisements

Repair Difficulty

Easy 2/5

Required Part

Condensate Trap
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements