Rheem Tankless Water Heater Not Heating No Error Code: How to Fix It

Rheem tankless water heaters are efficient appliances that provide continuous hot water for your home. But sometimes, they may fail to heat water due to various reasons. If you are facing this issue with your Rheem tankless water heater, don’t worry. There are some simple steps you can take to troubleshoot and fix this problem.

In this blog post, we will answer some common questions about Rheem tankless water heater not heating no error code issue.

What Causes Rheem Tankless Water Heater Not Heating No Error Code?

There are several possible reasons why your Rheem tankless water heater may not heat water without showing any error code, such as:

• Low flow rate. Your water heater has a minimum flow rate that triggers the heating process. If the flow rate of the incoming water is too low due to low water pressure, clogged filters, or faulty fixtures, the water heater will not detect the flow and heat water¹².
• Sediment buildup. Your water heater has a heat exchanger that heats the water as it passes through it. If the heat exchanger is coated with sediment or mineral deposits, it will reduce its efficiency and performance and cause the water heater to produce no hot water or insufficient hot water¹²³.
• Gas supply issue. Your water heater needs a sufficient and consistent gas supply to operate. If the gas valve is partially opened or closed, the gas pressure or volume is too high or low, or the gas line is leaking or damaged, the water heater will not heat water properly.
• Ignition failure. Your water heater has an igniter that sparks the gas burner to heat the water. If the igniter is faulty or dirty, the gas solenoid valve is open or short-circuited, or the flame rod is defective, the water heater will not ignite and heat water¹²⁴.
• Air supply blockage. Your water heater has a venting system that removes the exhaust gases from the combustion chamber safely. If the venting system is clogged with dirt, debris, or insects, the combustion process will be affected and the water heater will not heat water.

How To Fix Rheem Tankless Water Heater Not Heating No Error Code?

Depending on the cause of the not heating no error code issue, you may need to perform different steps to fix it. Here are some general tips to troubleshoot and resolve this issue:

• Check the flow rate. Check the incoming water pressure and make sure it is within the manufacturer’s specifications. You can use a pressure gauge to measure the water pressure at the nearest faucet. The ideal water pressure range is between 30 and 80 psi . If the water pressure is too low, you may need to adjust the pressure regulator or contact your water supplier. You should also check the inlet filter and the showerheads for any clogs or debris that may reduce the water flow. You can clean the filter and the showerheads with a soft brush or vinegar .
• Check the heat exchanger. Check the heat exchanger for any signs of sediment or mineral buildup. You may need to flush the water heater with vinegar or a descaling solution to remove the deposits and restore the efficiency of the heat exchanger . You can follow the instructions in the user manual or watch this video for a step-by-step guide:

• Check the gas supply. Check the gas valve and make sure it is fully opened. You can also check the gas pressure and volume with a manometer and make sure they are within the manufacturer’s specifications. You should also check the gas line for any leaks or damage and repair them if needed .
• Check the igniter. Check the igniter for any signs of damage or dirt. You may need to replace the igniter if it is faulty or clean it with a soft brush or compressed air if it is dirty . You should also check the gas solenoid valve and the flame rod for any signs of open or short circuit and replace them if needed .
• Check the venting system. Check the venting system for any signs of blockage or damage. You may need to clear any dirt, debris, or insects that may clog the venting system with a soft brush or compressed air . You should also check the venting pipes for any cracks, holes, or corrosion and repair them if needed .

By following these tips, you may be able to fix the not heating no error code issue on your Rheem tankless water heater and restore its normal function. However, if the issue persists or you are unsure how to perform any of these steps, it is best to call a licensed plumber who can diagnose and repair the problem safely and efficiently.

How to Prevent Rheem Tankless Water Heater Not Heating No Error Code Issue?

The best way to prevent Rheem tankless water heater not heating no error code issue is to perform regular maintenance and inspection on your water heater. Here are some tips to keep your water heater in good condition:

• Check the power supply and the circuit breaker regularly and make sure they are working properly.
• Check the flow rate and the water pressure regularly and make sure they are sufficient and consistent for your water heater.
• Flush the water heater with vinegar or a descaling solution at least once a year or more often if you have hard water. This will prevent sediment or mineral buildup on the heat exchanger and improve its efficiency and performance.
• Check the gas supply and pressure regularly and make sure they are adequate and stable for your water heater