Riello Flow Restriction Under Load

Boiler starts normally but shuts down when multiple radiators heat up

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.

Possible Causes

Undersized circulation pump, Blocked system filter, Partially closed isolation valves, Sludge build-up in return pipe

Safety: Allow the system to cool before handling valves or filters.

Check isolation valves: Ensure the boiler flow and return isolation valves are fully open.
Clean filters: Service any inline strainers or magnetic filters on the return.
Pump speed: Increase pump speed setting if adjustable and appropriate for the system.
Professional system clean: If problems persist, a heating engineer should flush the system and verify pump sizing.

Medium 3/5

Primary Circulation Pump

Check Price on Amazon

We may earn a commission from links on this page.