Ruud 33 Error Code
Neutralizer is clogged
Source: hvac/ruud/c327d936__RUD-rutgh-84dvln-2_pm.pdf
What does Ruud 33 mean?
On Ruud RUTGH condensing tankless water heaters, error code 33 means the neutralizer is clogged. Condensing units produce acidic condensate that passes through a neutralizer before draining; when that neutralizer becomes clogged, condensate cannot drain properly and the controller displays code 33.
Symptoms
- 33 shown on the remote control LED display
- Condensate not draining properly
- Possible water around the unit's condensate path
- Heater faults or stops operating
Common causes
- Neutralizer media clogged or saturated
- Restricted condensate drainage
- Overdue neutralizer maintenance
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Diagnostic steps
Note the code
Record that 33 is displayed. The neutralizer and condensate system are not user-serviceable internals.
Check for obvious condensate drainage problems
Without opening the unit, look for any blocked or kinked condensate drain routing to the proper drain.
Restart and recheck
Turn off the faucets, turn off the heater, unplug for about 30 seconds, plug back in, restart, and recheck the display.
Contact a dealer or qualified service technician
The manual's solution for code 33 is to contact a dealer or qualified service technician to service or replace the clogged neutralizer.
When to call a professional
Call a dealer or qualified service technician for code 33. The manual cautions that condensate is acidic and must be handled per federal, state, and local codes, and that the unit must not run without the condensate collector drain connected to a proper drain. Servicing the neutralizer and acidic condensate system is a job for a qualified professional, not a homeowner.
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Other Ruud Error Codes
Lime/scale buildup detected — flush or descale the heat exchanger
Air intake or vent exhaust opening may be blocked
Vent pipes on the vent termination may not be connected properly
Gas shut-off valve is not fully opened
Gas service has been interrupted
LP gas is running low (LP models only)
Code still displayed after the basic recovery steps — service needed
Water heater is overheating
The heat exchanger is too hot
Faulty inlet thermistor
Faulty outlet thermistor
Faulty blower motor