Boiler leaking water from bottom of cabinet

Safety first: Turn off power and close the boiler isolation valves. Hot water can cause burns and leaks can damage property.

• 1. Identify fluid type: Touch and smell the liquid carefully. Clear, cool, slightly acidic water near a condensing boiler may be condensate; warm, possibly discolored water under piping is likely system water.
• 2. Check relief valve: Inspect the pressure relief valve discharge pipe. If it is dripping, read the system pressure. High pressure may indicate an expansion tank or fill valve problem.
• 3. Inspect visible joints: Look at unions, circulator flanges, sensor wells, and manifold gaskets for signs of seepage or mineral deposits.
• 4. Condensate sources: On condensing models, check the condensate trap and tubing for cracks or loose connections.
• 5. Contain the leak: Place a pan or towels to protect surrounding areas and call a professional if the leak source is not obvious or is from the heat exchanger.