Grant
Water Leak from Boiler or Pipework
Boiler leaking water from underneath the casing or from pipe joints nearby.
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
Corroded heat exchanger, Leaking pump union, Faulty automatic air vent, Dripping pressure relief valve discharge
How to Fix / Troubleshooting
Safety: Isolate electrical power to the boiler immediately if water is leaking onto electrical components. Risk of electric shock.
User actions:
- Place a container or towels under the leak to minimise damage.
- Note the location of the leak (front, rear, left, right) to inform the engineer.
- If leak is severe, close the isolation valves to the boiler if accessible.
Engineer actions:
- Identify the source: pump unions, PRV, AAV, heat exchanger joints.
- Reseal or replace leaking pump unions and apply new fibre washers if required.
- Replace a leaking automatic air vent or pressure relief valve.
- If the primary heat exchanger is leaking, replacement of the exchanger or boiler may be required.
Advertisements
Repair Difficulty
Hard
4/5
Required Part
Automatic air vent
Check Price on Amazon
We may earn a commission from links on this page.
Advertisements