E26
Keston
DHW Overheat / Flow Restriction
Boiler intermittently shows E26, particularly when DHW demand is low
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
Scaled plate heat exchanger, Partially closed DHW isolation valve, Blocked DHW filter, Faulty modulating gas valve
How to Fix / Troubleshooting
Safety: Risk of scalding from taps. Warn occupants and avoid very hot water use.
User checks:
- Open hot taps fully rather than trickling to reduce overheating risk.
- If E26 persists, stop using hot water from the boiler and call an engineer.
Engineer checks:
- Inspect and clean the DHW inlet filter and any strainers on the Keston boiler.
- Descale or replace the plate heat exchanger if limescale is restricting flow.
- Check DHW flow rate and ensure isolation valves are fully open.
- Verify correct gas valve modulation during DHW operation using a flue gas analyser.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Plate Heat Exchanger
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements