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Atwood Water Heater Troubleshooting Manual

Atwood Water Heater Troubleshooting Manual

Atwood is one of the best manufacturers of gas and gas/electric combination water heaters for recreation vehicles (RVs). However, poor maintenance and overlong service of the unit can bring about some performance issues.

Atwood water heaters are very easy to fix with some readily available basic tools and a little expertise on how the water heater works. The following is a step-by-step guide on how to troubleshoot your Atwood water heater.

How to set up a new Atwood water heater

Follow the instructions below to remove and replace your Atwood heater;

Remove the older water heater.

  • Cut off the 110v power, gas, electricity, and water connection going into your older water heater. Ensure the water in the heater cools off before proceeding.
  • Remove the drain plug from the water tank and completely drain your water heater.
  • Follow the gas line, which runs through a grommet in a hole filled with sealant. Peel off the adhesive with a utility knife and a pair of pliers and then disconnect the unit’s gas line.
  • Disconnect the water lines at the back of the water heater by unscrewing the fasteners holding the unit’s lines.
  • Remove the screws securing the water heater to the body of the RV.
  • Pull the old water heater out a couple of inches to expose the electrical wiring.
  • Make a note of how the colored lines connect. Keep in mind that the RV wires’ colors don’t always match the water heater electrical wires.
  • Disconnect the 110v connection and then carefully remove the old water heater from its compartment.

Install the new Atwood water heater.

  • Use channel lock pliers to bend the edges around the panel’s perimeter to about 90 degrees to may way for the water heater.
  • Remove the wrapping and packaging from your unit and inspect for any dents and shipping damages.
  • Insert the new water heater partially into the access panel.
  • Remove the grommet sealing the gas line hole on the unit, thread the gas line through the hole to connect it to the unit. Cut one side of the grommet, fit it over the gas line, and secure the grommet with caulk or silicone sealant to avoid gas leaks.
  • Splice and reconnect the electrical wires using wire connectors or electrical tape.
  • Fully push the water heater into its compartment and secure it in place with the mounting screws.
  • Connect the water pipes and use silicone or calk sealant on the mounting flange to prevent leaking.
  • Turn off the water cut-off valve and switch on the propane tank.
  • Fill the water heater and check for leaks.
  • If there are no leaks, replace the rear access cover.

How to manual reset an Atwood water heater

Atwood water heaters have a safety mechanism that cuts off electricity when it senses a power surge or if the system gets too hot. Here is how to reset your Atwood water heater.

  • Turn off the power to the Atwood water heater.
  • Using a socket wrench, unscrew the nuts holding the thermostat junction box cover to the unit’s back, and pull the cover away.
  • Locate the red reset button protruding near the heating element.
  • Push the reset button until you hear it click into place.
  • If it doesn’t stay retracted, wait for about 10 minutes and push it in place.
  • Replace the junction box cover on the back of the unit and screw in the nuts.
  • Turn on the water heater.

Atwood water heater won’t stay lit.

If your water heater does not stay lit, there could be a defective thermostatic control or thermocouple; here is how to troubleshoot it;

  • Hold the knob longer since it may take some for the gas valve / electric board to get the signal from the thermocouple, indicating that the flame is present.
  • Ensure that the pilot flame is clean and reposition it to stay in contact with the end of the thermocouple probe. The thermocouple sits above the pilot flame.
  • Check the thermostatic control, which is part of the gas valve assembly with a dial that allows temperature adjustment and monitors water temperature. If the polite outage won’t stay lit, it is defective and needs a replacement by a trained gas technician.
  • Check if anything is blocking the U-tube and remove the obstruction.
  • You may have the incorrect pressure reading. Adjust the pressure to a minimum of 11˝ W.C.

Atwood water heater has no hot water.

If your water heater is not heating the water, here is how to fix the issue;

  • If you have an electric water heater, rule out any power problems first. Switch on any tripped breaker in the fuse box and replace and blown out fuses.
  • Check if the bypass valve is off or on. The bypass valve winterizes the water heater, so you need to turn the valve to the off position.
  • Look out for any open faucets. If more than one faucet is open simultaneously, cold water will flow out of one and hot water from the other. Smaller water heater models are not able to have two open faucets and the same time while allowing hot water to flow from both.
  • Check the temperature selector and reset the water temperature again.
  • Check the handle on the bypass valve line. If the valve is open, you bypass the water heater, and no hot water will go through. Close the valve to disengage the bypass.
  • Check if the U-tube is blocked and remove any blockage from the tube and burner, preventing water from heating adequately.
  • Ensure the thermostat is making open contact with the aluminum tank for proper temperature monitoring. It should be set at HI position and heat the water at 130 degrees. Replace it if it is defective.

Atwood water heater has no spark on the electrodes

Electrodes provide power to the anode rods, which prevent rusting inside the water heater. Here are the troubleshooting tips when your water heater produces no spark on the electrodes.

  • Check the electrode and primary burner connection. Tighten the screws holding the electrodes to the main burner.
  • Check if the electrodes are overlapping. Reset the position of the electrodes and allow about an inch of space between each one.
  • Carefully clean the dirty electrodes. Electrodes that have accumulated dust and dirt on them do not conduct electricity properly.
  • Ensure the insulation on the electrodes is not damaged and replace them if they are too old. If replacing the insulation does not work, you should get new electrodes.
  • Secure any loose electrical wire connections on the circuit board.
  • If the circuit board is unresponsive, you should replace it.

Gas burner is not igniting

If the gas burner does not ignite, the water will not warm up at all. To fix a gas burner that’s not igniting;

  • Check for loose wires that may hinder the propane from igniting and heating the burner. If you notice any loose wires, tighten them to allow the gas to flow steadily.
  • Check the airline’s condition. Looks for any clogs like dirt, dust, or soot and clean them out.
  • Align the flame spreader if it is out of line.
  • Unblock the U-tube or the main burner. Remove any dust and bugs from the burner nozzle and tube.
  • If the burner has rust, you should get a replacement.
  • If your water heater has been in storage for so long, it may accumulate air in the airlines. Bleed out the trapped air and dust from the airline, and the burner will ignite once all the air is out of the system.

Soot build-up signs, causes, and fixes

The water heater produces soot when excess carbon monoxide mixes with the gas in a water heater. Accumulation of dirt and debris in the burner inhibits the proper flow; dirt and dust in the vents prevent carbon monoxide from flowing out.

A tightly sealed set will also prevent sufficient oxygen from getting into the unit. Before troubleshooting, you need to clean the soot from the unit to avoid future blockages. Here is how to troubleshoot further production of soot;

  • Check your gas tank and refill it if it’s running on empty.
  • Remove any blockages from the main burner, U-tube, and exhaust grille and carefully clean them.
  • Check the alignment of the main burner, air valve, air shutter, and flame spreader. Look for loose screws and tighten them, clean off any corrosion or limescale build-up.

How do I know if my water heater thermostat is bad?

A water heater has two thermostats that control two different heating elements- one on the top and the other on the bottom. If you open the hot water tap and the cold water comes out, the upper thermostat is defective. If the hot water cannot stay hot after some time, the lower thermostat is defective. It is best to test each thermostat with a multimeter to know which one needs replacing. Here is how to test a water heater thermostat;

  • Turn the power off to the water heater at the circuit breaker.
  • Open the top and bottom access panels using a screwdriver.
  • Carefully lift off the insulation that covers the thermostat and heating elements without pulling out any wires.
  • Turn the temperature to the highest setting on the upper thermostat.
  • Set the multimeter to the RX1 setting.
  • Place one probe on the left terminal with the white wire and the other probe on the terminal above the white wire. The multimeter should read zero if the thermostat is working well.
  • Turn the upper thermostat to the lowest temperature setting until you hear a click.
  • Put one probe on the terminal above the white wire and another on the terminal with the black wire. The reading on the thermostat should be zero, and any other reading means the thermostat is faulty.
  • Leave the upper thermostat on the lowest setting and test the lower thermostat.
  • Set the lower thermostat to the highest setting.
  • Place one probe on the two terminals on the thermostat. The reading should be zero.
  • Replace any faulty thermostat, secure the access panel cover and turn on the water heater.

Why can’t I reset my Atwood water heater?

Several reasons could cause your reset button to keep tripping. If the reset button trips frequently, you need to address the issue’s source to prevent the switch from tripping. Here are the reasons you cant reset your Atwood water heater.

Your water heater is getting too hot due to a faulty thermostat in either the upper or lower heating element.

  • A malfunctioning high-limit switch keeps overheating the water.
  • Loose wiring in the heating element can prevent the unit from resetting.
  • A short in the heating element causes the water to overheat.
  • A power surge in your house or RV may prevent the water heater from resetting.

Check this too: RV Propane Regulator Troubleshooting & How to Guide


With this guide, you will be able to install your new Atwood water heater and fix most of the issues that may arise. Maintain your water heater by cleaning and dusting it regularly to reduce the build-up of dust