RV Water Heater Troubleshooting Guide

When a hot water heater system fails, it can be incredibly frustrating. After all, nobody wants to stand under a stream of freezing-cold water when they could be enjoying the comfort of a hot, steamy shower.

Common RV water heater issues include but are not limited to:

1. Hot water takes longer to reach temperature
2. Low hot water flow at the faucet
3. No hot water at the tap
4. Hot water temperature is too low
5. Water is escaping at the pressure relief valve
6. Water is leaking at the inlet filter
7. The power status LED is off although an operating mode was selected
8. The water heater stops working often and water is found on the drainage tray

The good news is that troubleshooting your RV water heater is a fairly easy process after you identify the exact problem the unit is having. In this RV water heater troubleshooting guide, we’ll look at common issues that could arise with the water heater in your RV, how to fix them and how to prevent future issues from occurring.

Before you start analyzing issues with your water heater, it’s important to understand how your RV gets hot water in the first place. Just like a residential home, an RV is equipped with a water heater. There are several different types of hot water heaters, including propane, gas, electric, solar, tankless (on-demand) and combination units, among others. Each of these systems works in slightly different ways to heat incoming water so that you can enjoy your shower or properly clean the dirty dishes in your camper.

The main thing you need to consider when troubleshooting your RV’s water heater is your water heater model. Since there are so many different types of RV water heaters, each model can vary and be somewhat different to troubleshoot. The steps in this guide reflect the process of troubleshooting a Furrion tankless water heater, specifically models FWH09AFA, FWH09A-AM, FWH09AFA-AM and FWH09AFA-AB. Other water heaters may differ. Always refer to your water heater or RV owner’s manual for instructions specific to your unit.

That said, let’s take a look at some of the error codes you may come across when your water heater is malfunctioning.

If your water heater malfunctions, a beeping alarm will sound and an error code will display on the wall controller, or thermostat. Write down the error code, then try resolving it by stopping and restarting the water flow or resetting the appliance.

You can reset the water heater using the following steps:

• Flip the power switch in front of the water heater to the “OFF” position. 
• Wait five seconds.
• Switch the appliance on again.

After you turn the water heater back on, you should be able to continue to use it normally. If error fault codes continue to display, review the following table for potential causes.

If you encounter a problem and find that your RV hot water heater is not working, try the suggested solutions below first. If problems persist, you should contact Furrion or call the dealer. Don’t repair the appliance by yourself, as repairs must be performed by a certified service technician.

Let’s look at a few common problems that could arise with your water heater.

If you find the hot water in your RV is taking a long time to reach the appropriate temperature, there could be a few different issues at play.

Cause 1: Cold water could be mixing into the hot water side of the water heater.
Solution 1: Check all valves, inside and outside, to ensure they are closed. Also, check the shower head valve to make sure it’s not partially closed.

Cause 2: You could be at a high elevation.
Solution 2: It is normal for water temperature heat-up time to increase when there’s less oxygen in the air. Furrion tankless water heaters have been tested up to 4,500 ft. For prolonged use at higher altitudes, contact Furrion to resolve this issue.

Cause 3: The incoming water temperature is abnormally low.
Solution 3: The water heater is equipped with a water flow control valve, set from the factory at MAX flow. The valve will reduce the water flow and capacity through the water heater to improve water heating performance. Under extreme conditions, it may be necessary to adjust the valve accordingly:

• Cold water inlet conditions approximately less than 45°F (7°C) 
• Higher water inlet pressures >65 psi

To adjust the valve for reduced water flow, rotate the knob clockwise until you feel a solid stop. To increase water flow, rotate the knob counterclockwise until it stops.

Lime scale can occur due to precipitation of "hard" water. The solution here is to decalcify your water heater. For prolonged usage when exposed to higher water hardness concentrations, it is advised to provide a proper water treatment device for the incoming water to the coach. Hard water may lead to performance reduction of your appliance over time. Contact Furrion for decalcification instructions.

Running out of hot water is never fun! Nobody likes the feeling you get after the sudden realization that your hot water isn’t working properly. Before you panic, read through the following causes to see if they apply to your situation and work through the solutions accordingly.

Cause 1: The gas supply is turned off or has been interrupted.
Solution 1: Check the gas supply to ensure that it is turned on and has not been interrupted.

Cause 2: The gas tank is empty.
Solution 2: Refill or replace the gas tank.

Cause 3: The appliance is switched off.
Solution 3: Okay, so it’s kind of obvious: you’ll need to switch on the appliance. To do this, ensure all necessary system leak tests are complete using your Furrion water heater user manual. Failure to follow these instructions could lead to serious injury or damage to your water heater.

After the leak tests are complete, follow these steps:

1. Verify the power switch is in the “OFF” position.
2. Confirm that there is a “steady” water flow (not pulsating) and that there’s no air in the system. If pulsating, have the water pump settings adjusted.
3. Make certain all valves that can mix cold and hot water are all shut. Outside faucets with detachable spigots and shower heads with flow interrupters can bleed hot water into the cold side if the valves are not closed properly. This will hinder the performance of the water heater.
4. Turn the power switch to the “ON” position and verify the wall controller, or thermostat, is illuminated. If the wall controller is not illuminated, press the button on the wall controller to illuminate. The wall controller display will show the hot water temperature setting. The default factory setting is 115°F or 46°C.
5. Turn on the gas supply.
6. Open a hot water faucet and verify that the unit ignites and supplies hot water at the faucet.
7. The wall controller display will show the current temperature settings.

Cause 4: The fresh water supply is turned off.
Solution 4: Open the fresh water supply.

Cause 5: The power supply to the water heater is switched off.
Solution 5: Switch on the power supply.

Cause 6: There’s a defect in the appliance.
Solution 6: Contact Furrion immediately.

Cause 1: Gas flow to the appliance is too low (gas inlet pressure 11 in. WC).
Solution 1: Consult vehicle documentation to determine if gas supply is capable of providing the necessary volume of gas for the appliance or contact a service technician to verify a suitable gas installation.

Cause 2: Volume flow of the hot water is too high and/or the temperature of the cold water reaching the appliance is too low.
Solution 2: Turn down hot water at the tap or in the shower in order to reduce volume flow or mix more cold water in the faucet. You could also potentially retrofit a volume flow throttle into the water system. This must be performed by a certified service technician, though.

Cause 3: Too much lime scale in the appliance.
Solution 3: Decalcify your water heater. See the above “low hot water flow at the faucet” section to properly descale your water heater.

Cause 4: Cold water is mixing into the hot water side.
Solution 4: Check all valves, inside and outside, to ensure they are closed. Also, check the shower head valve to make sure it is not partially closed.

Cause 1: Water pressure in the system is too high
Solution 1: There are a few things you could do to fix this. First, adjust the water pump pressure to a maximum of 65 psi. If the water system is connected to a central water supply higher than 65 psi (rural or urban connection), a water pressure reducer must be used. Install a water pressure regulator at the fresh water supply.

Cause 2: Lime or dirt is present under the pressure relief valve seat.
Solution 2: Allow the appliance to cool, then slowly operate the relief valve by rotating its valve handle to flush the water system, and attempt to force dirt or foreign matter out of the pressure relief valve seat. Replace pressure relief valve (this must be performed only by a certified service technician).

This issue likely stems from lime or dirt caked under the O-ring seats. To fix this, clean the O-rings and their corresponding sealing surfaces with clean water.

Cause 1: The power supply to the water heater is switched off.
Solution 1: Switch on the power supply.

Cause 2: There’s a blown fuse.
Solution 2: Switch the standard 125V/10A fuse and contact Furrion for service.

The cause of this problem is that the unit is overheating, making the pressure relief valve discharge periodically. Contact Furrion to solve this problem.

Routine inspection is critical for maintaining proper operation of your RV water heater. Unless specified, review the following items yearly or before each season.

1. Have the gas system and installation inspected every two years, or otherwise specified by your RV coach manufacturer, by a qualified technician.
2. Inspect for cracks, separation, peeling of seals to the RV wall. Remove and re-seal as necessary using caulking or tape between the side wall and the door of the water heater and ensure that the unit is solidly mounted to the vehicle.
3. Verify that the air inlet openings (louvers) are completely open and clear of any debris, including mud, leaves, twigs, insects, etc. Any obstructions can hinder full air flow.
4. Before actively using the vehicle, verify that the exhaust tube and screen are completely clear of obstructions. Clean them by gently breaking up the debris and using a vacuum to clear it. Use only water and apply it gently from a spray bottle. NEVER spray the unit directly with high pressure. Run the appliance to dry any moisture and blow out loose debris. The use of any aftermarket protective screen is prohibited and will void the warranty.
5. Before actively using the vehicle, open the door and verify that no debris or extraneous combustible materials are present anywhere (especially in the area of the burner and the gas controls). Remove any item present and wipe the bottom of the housing clean.
6. Inspect the interior surface of the housing for any cracks or corroded areas that could allow penetration of gases into or out of the interior of the vehicle. Check especially around the hot water, cold water, gas and electrical connections. If damages are found, please contact a technician to repair or contact Furrion customer service.
7. Check that all wire connections are firmly in place and there are no signs of chafing or cracks on the insulation. Verify that the spark ignition cable between the Control Board and the igniter is securely in place and not shorted to any metal component.
8. Inspect the pressure safety valve to ensure it has not been leaking (no water residue). As a rule, you should never tamper with the pressure relief valve, as it will void the warranty, and you should not actuate it while the water heater is in operation. However, the pressure safety valve needs to operate once each year to ensure its effectiveness. It's a safety component and must not be removed for any reason other than replacement, which should only be done by a certified service technician.
9. Inspect, clean and/or replace the water inlet filter as necessary. To do this, open the door of the water heater and remove the baffle. Then unscrew the filter cover by hand or by using a proper tool in the counterclockwise direction. Clean the screen filter by flushing any accumulated debris, then screw the filter cover back in, put the baffle back and close the water heater door.
10. Turn on the power to the water heater and open a hot water faucet to inspect the flame of the burner. The flame should be of the normal bluish appearance that indicates proper combustion. This can be accomplished by removing the water heater door and baffle to observe the flames by looking at the burner under the edge of the heat exchanger.
11. A sealing ring is assembled on the chimney. Inspect it to make sure the seal does not have any cracks or breaks, and that it is in good condition. Contact Furrion for a replacement, if needed. When installing the seal, make sure the words "INSIDE" are facing inward.

If you’re looking for additional RV water heater troubleshooting tips and information, you can download the full Furrion 2.4 GPM Tankless Gas Water Heater User Manual or visit support.lci1.com/waterheater.