How to Fix / Troubleshooting

Safety first: Allow the system to cool and isolate power before opening any inspection ports.

Flush the cylinder: Connect a hose to the drain valve and flush until water runs clear. This may remove loose rust and sediment.
Inspect anode (if fitted): Some Oso models have a sacrificial anode accessible from the top. Remove and inspect; replace if more than ~75% consumed.
Check for leaks: Look for signs of external corrosion or weeping seams, which may indicate internal damage.
Water quality: If corrosion is recurrent, have the water chemistry tested and consider treatment options.

If the cylinder itself is corroding through, replacement of the entire Oso water heater may be required.

Oso water heater emits a metallic or rusty discoloration in hot water.

Possible Causes