31 🟡 Repair Required
Ruud Error Code 31: Inlet Water Filter
⚠️ Your Ruud tankless water heater has detected a possible blockage in the inlet water filter, which can cause the unit to shut down. This requires troubleshooting to restore hot water.
How to Fix Ruud Code 31
- Step 1: Locate the inlet water filter on your Ruud tankless water heater. It's usually near the cold water inlet pipe.
- Step 2: Close the cold water shut-off valve to the unit.
- Step 3: Carefully remove the filter housing and inspect the filter. If it's visibly dirty, rinse it thoroughly under running water. For heavy buildup, soak it in a vinegar solution.
- Step 4: Reinstall the cleaned filter and filter housing, ensuring a tight seal. Open the cold water shut-off valve slowly.
- Step 5: If the error code persists after cleaning the filter, or if you're uncomfortable performing these steps, contact a qualified HVAC technician for assistance.
What Does Ruud Error Code 31 Mean?
The '31' error code on your Ruud tankless water heater indicates a potential issue with the inlet water filter. This filter is designed to prevent sediment and debris from entering the unit and damaging its internal components, like the heat exchanger. When the filter becomes clogged, it restricts water flow, causing the unit to operate inefficiently or shut down completely. This can lead to inconsistent hot water temperatures or a complete loss of hot water. Ignoring this error can lead to scaling and mineral buildup inside the heat exchanger, which is a much more costly repair.
Common Causes of Ruud Code 31
- Clogged inlet water filter due to sediment or debris buildup
- High mineral content in the water supply (hard water)
- Debris from recent plumbing work
- Damaged or deteriorated filter
Applicable Ruud Models
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Find a Licensed Tech Near You →Replacement Parts for Ruud HVAC System Code 31
Inlet Water Filter
Inlet Water Filter Housing