Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater 29 Error Fix: Condensate Drain / Vent Blockage

On condensing models like the RTGH series, this code indicates the condensate neutralizer or condensate drain line is blocked, or the exhaust/intake vent system is obstructed. Condensing tankless water heaters produce acidic condensate (pH 3-4) from the secondary stainless steel heat exchanger. This condensate must flow freely through the neutralizer (which raises the pH to safe levels) and out the drain. Check the condensate neutralizer cartridge — the limestone media inside becomes depleted over time and may need replacement. Clear the condensate drain line of any clogs or sediment. Verify the drain line slopes downward continuously to a proper floor drain. In cold climates, inspect the intake and exhaust vent terminations for ice buildup that can block airflow.

warning2 fixes available✨ Free fix available

Quick Answer

Error 29 on the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater means: Condensate Drain / Vent Blockage. The top-ranked community fix is “Replace Condensate Neutralizer Cartridge and Inspect Drain Line Slope” (medium difficulty, ~45 min, DIY cost: $15-$25). 2 community-ranked fixes available below.

Published February 2026 · 2 fixes · water heater

Content is based on manufacturer service documentation, community repair experience, and OEM technical bulletins. Always verify with your owner's manual.Learn about our editorial standards.

When to Call a Professional

While many water heater repairs can be done safely at home, consider hiring a qualified technician if:

The repair involves electrical wiring, gas lines, or refrigerant
You've tried the top-ranked fix and the error persists
You smell gas, see sparking, or notice water leaking
The repair requires specialized tools you don't have
Your appliance is still under manufacturer warranty

Average professional repair cost for this issue: $120-$180.

Other Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater Error Codes

False Flame Detection

2 fixes

Abnormal Combustion — Blocked Vent

2 fixes

Ignition Failure — No Flame Detected

2 fixes

Flame Failure — Flame Lost During Operation

2 fixes

Thermal Fuse Activated — Overheat Safety

2 fixes

Overheating — Outgoing Water Too Hot

2 fixes

Abnormal Temperature Rise — Low Water Flow

2 fixes

Outgoing Water Temperature Sensor Failure

2 fixes

People Also Ask About Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater Error 29

What does error code 29 mean on a Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater?

Error code 29 on the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater means: Condensate Drain / Vent Blockage. On condensing models like the RTGH series, this code indicates the condensate neutralizer or condensate drain line is blocked, or the exhaust/intake vent system is obstructed. Condensing tankless water heaters produce acidic condensate (pH 3-4) from the secondary stainless steel heat exchanger. This condensate must flow freely through the neutralizer (which raises the pH to safe levels) and out the drain. Check the condensate neutralizer cartridge — the limestone media inside becomes depleted over time and may need replacement. Clear the condensate drain line of any clogs or sediment. Verify the drain line slopes downward continuously to a proper floor drain. In cold climates, inspect the intake and exhaust vent terminations for ice buildup that can block airflow.

How do I fix error code 29 on my Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater?

The most successful fix is "Replace Condensate Neutralizer Cartridge and Inspect Drain Line Slope" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

Is error code 29 on a Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater serious?

This error is rated warning severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Can I fix Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater error 29 myself?

Yes — the top-ranked community fix ("Replace Condensate Neutralizer Cartridge and Inspect Drain Line Slope") is rated medium difficulty and takes about 45 minutes. Tools needed: T20 Torx screwdriver, Level tool, Bucket, Pipe clamps.

How much does it cost to repair Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater error 29?

DIY cost: $15-$25. Professional repair typically costs $120-$180. Many homeowners save money by trying the top-ranked community fix first.

What other error codes does the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater have?

The Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater has 8 other known error codes, including: 05 (False Flame Detection), 10 (Abnormal Combustion — Blocked Vent), 11 (Ignition Failure — No Flame Detected), 12 (Flame Failure — Flame Lost During Operation), 14 (Thermal Fuse Activated — Overheat Safety), and 3 more.

What other error codes does the Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater have?

The Rheem Rheem RTGH-95DVLN Prestige 9.5 GPM Condensing Tankless Gas Water Heater has 8 other known error codes:

05 — False Flame Detection (2 fixes)
10 — Abnormal Combustion — Blocked Vent (2 fixes)
11 — Ignition Failure — No Flame Detected (2 fixes)
12 — Flame Failure — Flame Lost During Operation (2 fixes)
14 — Thermal Fuse Activated — Overheat Safety (2 fixes)
16 — Overheating — Outgoing Water Too Hot (2 fixes)
24 — Abnormal Temperature Rise — Low Water Flow (2 fixes)
32 — Outgoing Water Temperature Sensor Failure (2 fixes)

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