5 Common Paloma Tankless Water Heater Error Codes

Paloma tankless water heaters are designed to operate maximally for 24 hours, 7 days a week, throughout the year. Occasionally, the unit may become faulty and you may notice an error code on the display often accompanied by a loud “beeping” alarm. Check the water heater’s digital display to identify the error code.

Common Paloma Tankless Water Heater Error Codes

There are 5 most common Paloma tankless water heater error codes: Error Code 00, Error Code 05, Error Code 11, Error Code 15, and Error Code 1L. Each signifies a specific issue that needs to be addressed including excessive combustion, faulty vent pipe connection, low water flow, sediment build-up, and lime build-up respectively.

Finding the Paloma water heater error code is not enough. Understanding what the code means to correctly diagnose the issue and resolve it is crucial. This article will explore these error codes and how to resolve the indicated issues.

Related: Rinnai vs Rheem Tankless water heaters. Which is better?

The 5 Most Common Paloma Tankless Heater Error Codes and How to Resolve Them


Paloma tankless water heater unit is not designed to operate continuously with a circulation system. So, if there is one hour of continuous combustion, you’re likely to get error code 00. The flow sensor will start beeping to alert you.

This error code is relatively easy to solve. You’ll need to close all the hot water taps to rest the water heater.


Error code 05 means the vent pipes might not be connected properly. Or the vent terminal is blocked. Aside from error code 05 displaying on the screen, you’ll hear the alarm beeping every minute, which stops when the hot water faucet is closed.

A blocked vent is a serious issue. A gas heater burns fossil fuels to generate carbon dioxide- which is a deadly and dangerous gas. If the water heater vent is blocked, it can cause carbon monoxide poisoning to the residents of the property.

To resolve error code 05, locate the vent pipe that vents the furnace. Remove the pipe and check for blockages. Remove any obstruction on the vent termination or air intake. It is advisable to contact a licensed dealer for the service and to adhre to the local codes for plumbing. Also, ensure that the blower motor is working correctly.


Error code 11

Error code 11 on your Paloma tankless water heater is an indication that the ignition is not working. It could also be a result of the gas valve not being fully open or a faulty assembly that is causing low gas pressure. There also might be a gas build up in the gas line which restricts the smooth flow of gas.

To resolve it, turn the power off and clean the flame rod, igniter, and solenoid valve. Check the burner assembly to ensure it is set up correctly. The Paloma tankless heater should be grounded well, and the natural gas supply system sized correctly



When the unit displays the error code 15, it means water flow is too low. This might be caused by sediment buildup. The fault code might not affect the heating system or water temperature, but the flow will be slow. Schedule regular water heater cleaning and maintainance to remove any built up sediments.



The error code 1L means there is a lime buildup in the system. This common error code can happen if you don’t check, clean, and maintain the system regularly. More so, if you live in places with hard water, the unit may display 1L code regularly.

Removing lime buildup can be a tricky task. White vinegar may loosen the lime, but only sufficient drainage will allow particles to flow out.


Paloma tankless water heater error codes are engineered to alert you to problems that may go unnoticed. Some codes are relatively easy to solve, while others need expertise. That’s why you’re strongly recommended to contact a licensed and insured plumbing contractor to deal with them. Always ensure that your water heater’s thermostat and thermistor are working properly.

Water Heater FAQs

What does code 11 mean on a Rinnai tankless water heater?

Code 11 on the Rinnai water heater means the unit is broken due to no gas supply to the tank.. Check and recheck the gas supply to the tank. If the gas is present but ignition fails to work the ignition system might be malfunctional. Have a water heater professional check the wiring of the tankless heater unit .

How do I reset the tankless water heater?

Your Rinnai or Rheem tankless water heater may give you an error code to alert you on a specific problem. Sometimes a reset is an ideal fix. Most models and brands are designed with a user-friendly interface for easy resetting using a reset button. Always consult the user’s manual for the ideal solution.

What does E5 mean on a tankless water heater?

The tankless heater displays error code E5 when the pressure switch has an issue. The problem might occur when the power supply voltage is low or the fan motor is faulty. If the issue persists even with the right voltage, you may reset the unit by shutting off the gas valve to limit the gas supply. Alternatively, completely drain the water out of the gas water heater.

How do you clean a Paloma tankless water heater?

Paloma tankless water heater requires less maintenance, but it needs regular cleaning. The first step is to shut the power supply or gas control valve in the case of a gas water heater. Then, shut off all the three water valves.

The blue valve is for cold water, red for hot water, and the last one is for the entire water supply to your home. The valves can be in the form of knobs or handles, depending on your hot water heater brand.

Remove the purge port valve caps and attach the housing lines to direct water into a bucket. Open the port to allow easy water flow into the bucket. After draining the unit, pump in the system with white vinegar and allow it to run between 45-90 minutes.Drain the vinegar and allow water to flow through the system. Plug in the system and let it operate as usual.

How do you troubleshoot the Rheem tankless water heater?

Rheem tankless water heater is a reliable model. The unit is packed with multiple features to ensure a continuous hot water supply in the house.

However, you may find some problems that might halt operations at home. If you’re seeing the Rheem error code, it’s time to diagnose the product. The unit comes with a programmable digital display to show the error code.

If you’re unfamiliar with the fault code on display, refer to the manual provided. But for safety measue, contact a qualified plumbing contractor to troubleshoot your Rheem water heater.

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