Rheem Water Heater Error Code 29: Meaning, Causes & How to Fix It
Learn what Rheem water heater error code 29 means, its common causes, and step-by-step troubleshooting methods to restore hot water.
ERROR CODES
6/15/20263 min read
If your Rheem tankless water heater is displaying Error Code 29, you're likely dealing with a problem related to the condensate system. This error is most commonly found on high-efficiency condensing tankless water heaters and indicates that the unit is having difficulty draining condensation properly.
Fortunately, many causes of Error Code 29 can be identified and resolved without major repairs.
What Does Rheem Error Code 29 Mean?
Rheem Error Code 29 generally indicates a condensate drain blockage or condensate system malfunction.
Condensing water heaters produce acidic condensation as part of the heating process. This moisture must be safely drained away through the condensate drain system.
When the system detects that condensation is not draining properly, it shuts down and displays Error Code 29 to prevent internal damage.
Common Causes of Rheem Error Code 29
Several issues can trigger this error.
1. Clogged Condensate Drain Line
The most common cause is a blocked condensate drain line.
Over time, the drain can become clogged by:
Dirt
Sediment
Debris
Mineral buildup
Algae or mold growth
When water cannot drain properly, the system triggers the error code.
2. Blocked Condensate Trap
Many Rheem condensing models include a condensate trap.
If this trap becomes clogged with debris, condensation can back up into the unit.
3. Frozen Condensate Line
In colder climates, condensate lines may freeze.
Ice inside the drain line prevents water from flowing properly and can cause Error Code 29.
4. Improper Drain Installation
A drain line that is incorrectly installed may prevent proper water flow.
Common installation issues include:
Improper slope
Kinked tubing
Sagging drain lines
Drain line obstructions
5. Faulty Condensate Sensor
Some models use sensors to monitor condensate levels.
A defective sensor may falsely report a drainage problem even when the system is operating correctly.
6. Condensate Pump Failure
If your installation uses a condensate pump, pump failure can prevent drainage and trigger the error code.
How to Fix Rheem Error Code 29
Follow these troubleshooting steps to identify and resolve the problem.
Step 1: Reset the Water Heater
Start with a simple reset.
Turn off the water heater.
Wait approximately 30 seconds.
Turn the unit back on.
Check if the error code returns.
If the error persists, continue troubleshooting.
Step 2: Inspect the Condensate Drain Line
Carefully examine the drain line for:
Blockages
Kinks
Cracks
Debris buildup
Clear any visible obstructions and ensure water can flow freely.
Step 3: Clean the Condensate Trap
If your model includes a condensate trap:
Turn off the unit.
Remove the trap according to the owner's manual.
Rinse it thoroughly with clean water.
Reinstall it properly.
A clogged trap is a common source of Error Code 29.
Step 4: Check for Frozen Lines
If temperatures have recently dropped, inspect the condensate drain line for ice.
Carefully thaw frozen sections using warm air or by moving the line to a warmer location if possible.
Never use open flames.
Step 5: Verify Proper Drainage Slope
Ensure the drain line slopes downward toward the drain location.
Standing water inside the line can trigger drainage issues.
Step 6: Inspect the Condensate Pump
If your system uses a condensate pump:
Verify it has power.
Listen for normal operation.
Check for blockages.
A malfunctioning pump may need repair or replacement.
Preventing Rheem Error Code 29
Routine maintenance can help prevent future condensate problems.
Clean the Drain Line Annually
Flushing the condensate line removes buildup before it causes blockages.
Inspect the Condensate Trap
Check the trap periodically and clean it as recommended by Rheem.
Protect Against Freezing
In cold climates:
Insulate exposed drain lines.
Keep installation areas above freezing temperatures when possible.
Schedule Professional Maintenance
Annual servicing helps identify drainage issues before they become major problems.
When to Call a Professional
Contact a licensed technician if:
Error Code 29 returns repeatedly
The condensate system appears damaged
The condensate pump fails
You cannot locate the blockage
Water is leaking inside the unit
Professional diagnosis may be required if sensors or internal components are malfunctioning.
Final Thoughts
Rheem Water Heater Error Code 29 usually indicates a condensate drainage problem. The most common causes include clogged drain lines, blocked condensate traps, frozen tubing, improper installation, or condensate pump failures. In many cases, cleaning the drain system and restoring proper water flow will resolve the issue.
Regular maintenance of the condensate drain system can help prevent Error Code 29, improve efficiency, and extend the life of your Rheem tankless water heater.
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