Aerco Water Heater Keeps Shutting Down: Here’s How to Fix It

Aerco Water Heater Keeps Shutting Down: Here’s How to Fix It

Aerco water heaters are known in the HVAC industry for their advanced modulating technology and integration with building management systems, ensuring consistent hot water delivery in demanding environments. However, even these reliable systems can experience unexpected shutdowns. Such issues can lead to system downtime, decreased performance, and disruptions in essential services. In this article, we’ll explore the common causes of Aerco water heater shutdowns, provide troubleshooting steps to resolve them, and outline maintenance strategies to prevent future problems.

Common Causes of Aerco Water Heater Shutdowns and How to Fix Them

Here are the common causes of Aerco water heater shutdowns and how to fix them effectively.

Overheating Due to a Faulty Thermostat

One of the most common causes of water heater shutdowns is overheating, which often results from a malfunctioning thermostat. When the thermostat fails to regulate the water temperature properly, the water heater can overheat, triggering an automatic shutdown to prevent potential damage.

Fix :

• Inspect the Thermostat Settings: To ensure it is set to an appropriate temperature. If it’s set too high, lower it to prevent overheating.

• Test the Thermostat: By comparing its readings with a separate temperature gauge. If the thermostat fails to match the temperature readings, it’s likely malfunctioning and needs to be replaced.

• Professional Inspection: If you’re unsure whether the thermostat is the issue, it’s recommended to consult a professional HVAC technician. Incorrect handling can lead to further damage.

  
  

Blocked or Clogged Vents

Aerco water heaters rely on an efficient venting system to expel exhaust gases safely. If the vents become clogged with debris, dust, or obstructions, the system may overheat because it can’t release the heat it generates. This safety mechanism causes the water heater to shut down to prevent damage.

Fix :

• Inspect the Venting System: For any visible blockages. Common culprits include dust, debris, and objects that may have fallen into the vents.

• Clean the Vents: Use a vacuum cleaner or a vent brush. This will help clear any accumulated dust or debris.

• Check the Vent Connections: For signs of damage, wear, or leaks. If any sections of the venting system are loose or disconnected, secure them or replace them with authentic Aerco parts to ensure proper airflow and prevent shutdowns.

  
  

Faulty Pressure Relief Valve

The pressure relief valve is a critical safety feature in any water heater, including Aerco units. It prevents excess pressure from building up inside the tank, which could lead to catastrophic failure or a dangerous rupture. If the valve is faulty or blocked, it can cause excessive pressure buildup, triggering an automatic shutdown.

Fix:

• Check the Pressure Relief Valve: To check the pressure relief valve, raise the lever. If water flows freely, the valve is likely working correctly. If there is no flow, the valve may be stuck or clogged and needs to be replaced.

• Replace a Faulty Valve: Pressure relief valves are relatively inexpensive and easy to replace. Ensure that the new valve is compatible with your Aerco water heater to avoid further issues.

  
  

Low Water Flow or Insufficient Water Supply

Water heaters depend on adequate water flow to operate effectively. If there is insufficient water supply or if the flow is obstructed, the heater can overheat and shut down. Common causes of low water flow include clogged filters, closed valves, or malfunctioning pumps.

Fix:

• Inspect Filters and Strainers: If these parts are dirty, clean them or replace them to restore proper water flow.

• Examine the Pump: If the pump is malfunctioning and not providing the necessary water circulation, it may need repair or replacement.

  
  

Electrical Issues

Electrical issues can also cause your Aerco water heater to shut down. If the system isn’t receiving the correct voltage or if a fuse has blown, the heater will fail to operate. Electrical malfunctions can be a result of faulty wiring, tripped circuit breakers, or worn-out electrical components.

Fix:

• Check the Circuit Breaker: If the breaker has tripped, reset it and observe whether the water heater resumes functioning.

• Inspect Wiring and Connections: Look for visible signs of wear or damage. If any wires are frayed or disconnected, replace them to ensure the water heater is getting a steady supply of electricity.

• Examine the Fuse: If the fuse is blown, replace it with one of the same specifications. Be sure to use a fuse designed for your particular model to avoid damaging the system.

  
  

Gas Supply Problems

For gas-powered Aerco water heaters, issues with the gas supply can prevent the burner from igniting properly, causing the unit to shut down. Gas supply issues can arise from a gas leak, a malfunctioning gas valve, or inadequate gas pressure.

Fix:

• Ensure the Gas Valve is Open: If the valve is closed or partially open, fully open it to restore the gas supply to the unit.

• Inspect the Gas Line: Look for leaks or blockages. If you detect any leaks, shut off the gas supply immediately and contact a professional technician to repair the line.

• Examine the Burner Assembly: Clean the burners to remove any debris or buildup that could obstruct gas flow and prevent proper ignition. If replacement is needed, use certified Aerco burner parts to maintain system performance.

  
  

Sediment Buildup

Hard water minerals can build up at the bottom of the water heater tank over time. This sediment buildup reduces the efficiency of the heater and can cause it to overheat, triggering a shutdown to prevent damage to the unit.

Fix:

• Drain the Tank: After connecting a hose to the drain valve, let the water run out. Continue draining until the water runs clear, which will indicate that most of the sediment has been removed.

• Flush the Tank: The tank should be flushed at least once a year to avoid additional sediment accumulation. If you live in an area with hard water, consider flushing the tank more frequently.

  
  

Sensor Malfunctions

Modern Aerco water heaters are equipped with sensors that monitor critical parameters such as temperature, pressure, and water flow. If one or more of these sensors malfunctions, it can trigger false alarms and cause the system to shut down to prevent further issues.

Fix:

• Inspect the Sensors: Ensure the sensors are clean and free from dirt or damage. If the sensors are dirty, clean them carefully to restore proper functionality.

• Test the Sensors: Use a multimeter to verify proper sensor readings. If the sensors are unresponsive or inaccurate, replacing them with genuine Aerco sensor parts is recommended to ensure compatibility with your system.

  
  

Preventing Future Shutdowns: Aerco Water Heater Maintenance Tips

To keep your system running reliably and avoid unexpected issues, here are the top Aerco water heater maintenance tips that can help prevent future shutdowns and extend the life of your unit.

Regularly Inspect and Clean the Vents

Proper ventilation is critical for your Aerco water heater to function safely. If the venting system becomes clogged or obstructed, exhaust gases may not be expelled properly, causing the unit to overheat and shut down.

Maintenance Tips:

• Perform visual inspections of all intake and exhaust vents at least quarterly.

• Clear any dust, debris, bird nests, or insulation that may block airflow.

• Use a vent brush or vacuum to clean inside the vent pipe.

• If vent seals or connectors are damaged, replace them with genuine Aerco parts to ensure air-tight performance.

  
  

Flush the Tank Periodically

Mineral-rich water (hard water) can leave deposits inside the heater's tank over time. This sediment reduces thermal efficiency, insulates heating elements, and can lead to premature system shutdowns due to overheating.

Maintenance Tips:

• Flush the water heater tank at least once a year by draining water through the bottom valve until it runs clear.

• In areas with hard water, consider biannual flushing or installing a water softener.

• If you notice poor drainage or damage to the drain valve, replace it with an OEM Aerco part to maintain system compatibility and reliability.

  
  

Check the Pressure Relief Valve

The temperature and pressure relief (TPR) valve is a vital safety component that prevents excessive pressure from building up in the tank. A stuck or leaking valve can trigger emergency shutdowns or create hazardous conditions.

Maintenance Tips:

• Test the TPR valve every six months by lifting its lever and confirming water discharges briefly from the discharge pipe.

• If no water flows or if the valve leaks constantly, it should be replaced immediately.

• Always use certified Aerco pressure relief valves to meet safety and performance standards.

  
  

Inspect the Electrical Components

Electrical problems such as frayed wires, corroded terminals, or weak connections are a frequent cause of unexpected heater shutdowns. Regular inspections can help identify these issues before they become critical.

Maintenance Tips:

• Power down the unit and open the control panel to inspect internal wiring.

• Look for discoloration, loose connections, or melted insulation.

• Replace damaged wires or relays with original Aerco parts to avoid incompatibility and ensure proper voltage handling.

  
  

Test the Thermostat Settings

The thermostat regulates water temperature and communicates with the control board. If it's set too high or begins to fail, the unit may overheat and shut down as a safety measure.

Maintenance Tips:

• Check that the thermostat is set to a manufacturer-recommended temperature, typically around 120–140°F (49–60°C).

• Compare the displayed temperature with a calibrated thermometer.

• If readings are inconsistent or the unit frequently overheats, replace the thermostat with a genuine Aerco thermostat for accurate temperature control.

  
  

Regular maintenance and timely replacement of worn components with genuine Aerco parts are essential to keeping your water heater running efficiently and preventing future shutdowns. To ensure safe and appropriate repairs, always seek the advice of a certified HVAC specialist.

Written by Allen Rode for PartsHnC, your trusted source for high-quality HVAC parts, including water heater components, air conditioner parts, and heat pump solutions.