CTC
Chronic Pressure Loss
Boiler frequently loses pressure and needs regular topping up via the filling loop.
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
Hidden leak in heating circuit, Faulty pressure relief valve passing, Flat or ruptured expansion vessel, Micro-leaks at radiator valves or joints
How to Fix / Troubleshooting
Safety: Do not repeatedly overfill the system above the maximum pressure. Allow the boiler to cool before working on the system.
- Check PRV discharge: Inspect the pressure relief valve discharge pipe outside. If it drips when the boiler heats, the PRV may be passing or the expansion vessel may be faulty.
- Inspect for visible leaks: Walk around the property checking radiators, valves, and accessible pipework for damp patches or staining.
- Expansion vessel test (technician): Isolate and drain system pressure, then measure the expansion vessel pre-charge. Recharge to the value specified by CTC or replace the vessel if waterlogged.
- Replace PRV (technician): If the PRV has lifted repeatedly, its seat may be damaged. Replace the pressure relief valve.
Advertisements
Repair Difficulty
Medium
3/5
Required Part
Expansion Vessel
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements