Ruud tankless water heater shows error code 29; unit may not operate in condensing mode or may shut down.

Safety first: Turn OFF power to the heater. Condensate is mildly acidic; wear gloves and eye protection.

• Step 1 – Inspect condensate line: Locate the condensate drain tubing from the bottom of the unit. Check for kinks, sags, or blockages. Clear any obstructions and ensure the line slopes continuously downward.
• Step 2 – Check condensate trap: Remove the trap (if external) and flush it with clean water to remove debris or sludge. Reinstall securely.
• Step 3 – Service neutralizer: If your Ruud model uses a condensate neutralizer cartridge, inspect it for saturation or blockage. Replace the neutralizer media or cartridge as recommended by the manufacturer.
• Step 4 – Protect from freezing: In cold climates, insulate the condensate line and ensure it drains to a frost-free location.

After clearing the drain system, restore power and test. If code 29 persists, the condensate level sensor or control board may require professional service.