If your underfloor heating pump looks like the below, has stopped working and has a green light flashing around the flow setting then this article should be read.
UFH pumps can sometimes fail for a few reasons:
- pump hasn't been run in a long time
- air in the system
- solid matter in the system
The above can all cause issue due to seizing or overheating, causing damage to the motor.
Generally, it is unlikely to be a manufacturing fault if the pump has been running after installation.
Sometimes the UFH pump can be fixed by following the steps below:
First purge the pump of air:
- Switch off the power to the pump, keep the ball valves open and pressure at the manifold.
- Release the central pump screw (do not remove) to vent any air trapped in the pump and re-tighten screw.
- Power back up the pump and run it.
If the green light is still flashing, check the impeller for movement:
- Switch off power to the pump, close the ball valves on the manifold to isolate.
- Release the central pump screw to release any pressure in the system (water will be released at this point!).
- Using a Hex Key (Allen Key), unscrew the four bolts holding the pump motor unit to the metal body and inspect the pump impeller. If there is discolouration or a build-up of material on the impeller and inner surfaces, it is a sign that water quality may be poor.
- Turn the pump impeller to see if it runs freely
- If it does, refit the pump, open the isolation valves, purge the air as above before reconnecting the power and running the pump.
- If the pump will not turn freely, the pump has likely become damaged from running without water (run dry) or has become jammed from solid material in the system. Rotating the impeller may free the obstruction, rectifying the issue. If rotating the impeller does not improve the movement of the impeller a replacement pump will need to be purchased.
- If the pump turns freely and the light is still flashing after refitting, the pump will need to be returned to us for testing and be replaced.
If the cause of the pump issue is water quality, this must be rectified by flushing the system and refilling with the appropriate levels of inhibitor. The fitting of a system filter is also recommended to prevent water quality issues reoccurring.
Failing to do so will result in further pump and manifold component failures.