Boiler leaking water from underneath the casing or from pipe connections.

Safety: Turn off power and close the boiler isolation valves. Place a container or towels under the boiler to catch drips.

• Identify leak source: Remove the lower cover and use a torch to trace where water is originating. Check around the pump, pressure relief valve discharge, and heat exchanger connections.
• Tighten unions (qualified person): Gently tighten any slightly loose compression nuts or pump unions, taking care not to overtighten.
• Check automatic air vent: Inspect the AAV on top of the pump or heat exchanger. If it is wet or constantly weeping, its cap or the entire vent may need replacement.
• Monitor pressure: Refill the system to the correct pressure and observe the gauge over several hours. A steady drop indicates an ongoing leak.

Leaks from the primary heat exchanger or hydraulic block usually require part replacement by an Alpha-approved engineer.