Glow-worm Chronic pressure loss / leak

Furnace frequently loses pressure, user has to top up system often

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

Leaking radiator or valve, Faulty pressure relief valve on Glow-worm hydraulic block, Failed expansion vessel, Hidden pipework leak

Safety: Repeated topping up can damage the system. Do not exceed the recommended pressure.

User steps:

Visually inspect radiators, valves, and visible pipework for signs of water staining or drips.
Check the discharge pipe outside (from the pressure relief valve) for signs of water discharge.

Technician steps:

Test the expansion vessel pre-charge and recharge or replace if the diaphragm has failed.
Inspect and, if necessary, replace the pressure relief valve if it is passing water.
Perform a pressure test on the system to locate hidden leaks.

Medium 3/5

Expansion Vessel / Pressure Relief Valve

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