E15 error, unit indicates low pressure or no water, may not fill correctly

Safety: Never bypass level or dry‑fire protection. Running immersions or boilers on an empty cylinder can cause severe damage or fire.

Steps:

• Confirm water supply: Check that the mains stopcock and any local isolation valves to the Gledhill unit are fully open.
• Bleed air: Open a hot tap and allow air to escape until a steady stream of water flows. This helps ensure the cylinder is full.
• Locate level sensor: Some Gledhill thermal stores use a float switch or conductivity probes in the top of the store. Inspect the sensor for signs of scaling or contamination.
• Clean or replace sensor: With power off and water level safely managed, remove the sensor and clean any scale. If the float is waterlogged or the probes are corroded, replace the assembly.
• Wiring check: Ensure the sensor cable is intact and firmly connected to the PCB.

Note: If E15 persists despite a full cylinder and a new sensor, the PCB input may be faulty and should be checked by a professional.