Rinnai Water Heater Error Code 19: How to Fix It

Q: Is it safe to use my Rinnai water heater while Error Code 19 is showing?

No. Error Code 19 indicates an electrical grounding fault, which is a safety condition. The unit shuts itself down to protect you. Do not attempt to bypass or repeatedly reset the unit to force it to run — resolve the underlying electrical issue first.

Q: What causes Rinnai Error Code 19?

The most common causes are a loose or disconnected ground wire at the unit or outlet, a faulty wall outlet or circuit, improper home wiring without a proper ground, a tripped GFCI outlet, or in some cases a failed internal component such as the control board that has developed an internal short to ground.

Q: Can I reset Rinnai Error Code 19 myself?

Yes, you can attempt a reset by powering the unit off, waiting 60 seconds, and powering it back on. However, if the error returns after resetting, a simple reset is not a fix — there is an underlying electrical fault that must be diagnosed and corrected before the unit will operate safely.

Q: Will a Rinnai Error Code 19 void my warranty if I try to fix it myself?

Performing DIY repairs on internal components or wiring inside the water heater itself may void your warranty. However, checking the external outlet, resetting the breaker, and inspecting accessible ground wire connections are generally considered routine homeowner tasks. To be safe, check your warranty terms or call Rinnai at 1-800-621-9419 before opening the unit.

Q: How much does it cost to repair Rinnai Error Code 19?

If the fix is simply tightening a loose ground wire or replacing a faulty outlet, the cost is minimal — under $20 for parts and your own labor. If an electrician is needed to correct home wiring issues, expect to pay $100–$300 depending on the scope. If the water heater's internal control board needs replacement, professional repair costs can range from $200–$600 including parts and labor.

Abstract

Rinnai Error Code 19 indicates an electrical grounding fault in your tankless water heater, meaning the unit has detected an abnormal electrical condition related to its grounding circuit. This is a safety-triggered shutdown designed to protect you and the appliance from potential electrical hazards. While some causes are simple fixes like a tripped breaker or loose wire, others may require a licensed professional to resolve safely.