Boiler leaking water from underneath or from side panels, puddles forming below Viadrus boiler.

Safety first: Turn off power and close the boiler isolation valves if fitted. Place containers or towels to catch water and prevent damage. Do not operate the boiler while it is leaking.

Step-by-step checks:

• 1. Identify leak location: Remove the front panel and use a torch to trace water back to its source. Check around the pump, heat exchanger joints, air vent, and safety valve outlet.
• 2. Tighten unions: If the leak is from a union or compression joint, gently tighten with a spanner while supporting the opposing fitting. Do not overtighten cast-iron sections.
• 3. Check safety valve: If water is dripping from the safety valve discharge pipe, system pressure may be too high or the valve seat may be fouled. Reduce system pressure to about 1.2 bar and operate the valve briefly to clear debris, then check if it reseals.
• 4. Inspect automatic air vent: If the air vent cap is wet, tighten the cap slightly (do not fully close if it is the only air vent) or replace the vent if it continues to leak.

When to stop: If the leak originates from the heat exchanger body or section gaskets, or if tightening joints does not stop the leak, contact a Viadrus specialist. Heat exchanger repairs often require partial boiler disassembly.