Having an error code 16 on your Rinnai tankless water heater can be frustrating, but fear not! This article will guide you through troubleshooting steps to help you resolve the issue and get your unit back up and running smoothly. Error code 16 is typically associated with air flow or water flow problems, as well as potential obstructions in the combustion chamber or exhaust piping. By following these steps, you’ll be able to identify and address the underlying causes of the error code, ensuring optimal performance and reliability of your Rinnai tankless water heater.

1. Check for restrictions in air flow around unit and vent terminal

Ensuring proper air flow is crucial for the efficient operation of your Rinnai tankless water heater. To check for restrictions in air flow, start by examining the area around the unit and the vent terminal. Look for any objects or debris that may be obstructing the air intake or vent terminal.

Remove any debris or obstructions that you find, such as leaves, dust, or other materials, from the air intake and vent terminal. This will allow for unrestricted air flow and prevent any potential issues caused by restricted ventilation.

Next, inspect the vent piping for any signs of damage or blockage. Look for dents, kinks, or other obstructions that may restrict the flow of exhaust gases. If you notice any damage, repair or replace the vent piping as needed.

It’s also important to ensure that there is sufficient clearance around the unit. Check the manufacturer’s specifications for the recommended clearance distances. Providing proper ventilation and maintaining the recommended clearances will help prevent air flow restrictions and optimize the performance of your tankless water heater.

2. Check for low water flow in a circulating system causing short cycling

If you have a circulating system connected to your Rinnai tankless water heater, low water flow can cause short cycling, which can lead to error code 16. To check for low water flow, follow these steps:

First, check the water flow rate in the circulating system. Refer to the Rinnai documentation or consult a professional to determine the minimum flow rate required for your specific model. Measure the flow rate using a flow meter or consult a plumber if you are unsure how to do this.

Inspect the circulating pump to ensure it is functioning properly. Look for any signs of damage or malfunction, such as unusual noises or leaks. If you suspect a problem with the pump, consider replacing it as it is a wear part.

Check for any valves in the circulating system that may be partially closed or obstructed. Inspect the valves and ensure they are fully open to allow adequate water flow. If any valves are partially closed or obstructed, open or replace them as needed.

Regular maintenance of the circulating system is also important. Periodically clean or flush the system to remove any debris or sediment that may restrict water flow. This will help maintain optimal performance and prevent issues related to low water flow.

3. Check for foreign materials in combustion chamber and/or exhaust piping

Foreign materials, such as debris or objects, in the combustion chamber or exhaust piping can interfere with the proper operation of your Rinnai tankless water heater and cause error code 16. To check for foreign materials, follow these steps:

Start by visually inspecting the combustion chamber and exhaust piping. Look for any signs of foreign materials, such as leaves, insects, or debris. If you spot any foreign materials, carefully remove them using appropriate tools or cleaning methods.

Regular maintenance and cleaning of the combustion chamber and exhaust piping are essential to prevent the accumulation of foreign materials.

4. Check for a clogged heat exchanger

A clogged heat exchanger can significantly impact the performance of your Rinnai tankless water heater. To check for a clogged heat exchanger, consider the following steps:

Start by turning off the power and gas supply to the unit. This is a critical safety precaution that should never be skipped before performing any maintenance or inspection tasks.

Inspect the heat exchanger for any signs of blockage or buildup. Look for scale, sediment, or mineral deposits that may restrict the flow of water through the exchanger. If you notice any buildup, it’s time to flush your Rinnai tankless water heater.

Regular maintenance and cleaning of the heat exchanger are crucial to ensure its efficient operation. Consult the owner’s manual or contact the manufacturer for specific maintenance guidelines and recommended cleaning intervals.

Conclusion

Resolving error code 16 on your Rinnai tankless water heater is achievable by following the troubleshooting steps outlined in this article. By checking for restrictions in air flow, low water flow in the circulating system, foreign materials in the combustion chamber or exhaust piping, and a clogged heat exchanger, you’ll be able to address the root causes of the error and restore your unit’s functionality.

If you encounter any challenges during the troubleshooting process or if the error persists after attempting these steps, it is recommended to contact a professional technician or plumber who specializes in Rinnai tankless water heaters. Their expertise and experience will ensure a thorough diagnosis and effective resolution of the issue, providing you with peace of mind and uninterrupted hot water supply.