How to Drain an RV Water Heater and Avoid Costly Repairs

Owning an RV brings with it the joy of adventure and the freedom to explore the open road. To ensure your mobile home continues to provide comfort and reliability, proper maintenance is crucial.

One essential aspect of RV care is regularly draining your RV water heater. In this comprehensive guide, we’ll walk you through the step-by-step process of how to drain an RV water heater.

RV water heater
RV water heater (photo:

We’ll also explain the importance of this task, discuss potential issues you might encounter, and provide valuable tips on how to avoid them.

Why Draining an RV Water Heater Is Important

The RV water heater in your mobile home serves the vital purpose of providing hot water for various daily activities, such as showering, cooking, and cleaning.

Over time, mineral deposits and sediment can accumulate at the bottom of the water heater tank. If left unchecked, these deposits can reduce the heater’s efficiency, decrease its lifespan, and even lead to potential malfunctions.

Draining is recommended at every season’s end and when storing for over two weeks. Extended storage may lead to stale or contaminated water, resulting in a sulfur odor and potential health concerns.

Draining your RV water heater regularly helps prevent these issues and ensures the system works optimally.

Step-by-Step Guide to Draining an RV Water Heater

Required Tools and Materials

To effectively drain your RV water heater, you’ll need a few basic tools and materials. Here’s a list of what you’ll require:

  1. Garden Hose: A standard garden hose will be used to connect to the drain valve and allow water to flow out of the tank.
  2. Bucket or Drainage Container: You may need a bucket or container to catch the initial water that comes out when you open the drain valve. This prevents water from pooling around the vehicle.
  3. Adjustable Wrench or Pliers: These tools will help you loosen and tighten any connections, such as the drain valve or pressure relief valve.
  4. Teflon Tape: Also known as plumber’s tape, this tape is used to create a watertight seal on threaded connections. You might need this when connecting or disconnecting the garden hose.
  5. Safety Gear: Since you’re working with hot water and steam, it’s a good idea to wear safety gloves and eye protection to prevent burns and splashing water.
  6. Owner’s Manual: Always have your RV’s owner’s manual on hand. It contains specific information about your water heater model and maintenance guidelines.
  7. Towels or Rags: Keep some towels or rags handy to wipe up any spills or drips that may occur during the process.

It’s important to have all the necessary tools and materials ready before you start the process to ensure a smooth and efficient draining of your RV water heater.


Follow these steps to effectively drain your RV water heater:

  1. Safety First: Before you start, make sure the water heater is turned off and the propane or electrical connections are disconnected.
  2. Cool Down: Allow the water heater to cool down for a few hours before draining. Hot water and steam can cause burns.
  3. Access the Water Heater: Depending on your RV’s model, locate the access panel on the exterior or interior where the water heater is situated.
  4. Turn Off Water Supply: Close the water supply valve to the water heater to prevent new water from entering the tank.
  5. Pressure Relief Valve: Before draining, release any built-up pressure by lifting the pressure relief valve. Be cautious of hot water and steam.
  6. Attach a Hose: Connect a garden hose to the drain valve located near the bottom of the water heater tank. Place the other end of the hose in a suitable drainage area.
  7. Open the Drain Valve: Slowly open the drain valve to allow the water to flow out. You can open the pressure relief valve or a hot water faucet inside your RV to facilitate drainage. Some models have standard drain valves while others anode rods.
  8. Flush the Tank: To remove sediment and mineral buildup, briefly open and close the cold water supply valve in intervals. This will help flush out the debris.
  9. Close Drain Valve: Once the water runs clear and free of sediment, close the drain valve.
  10. Refill the Tank: Close the pressure relief valve and cold water faucet. Reopen the water supply valve to the water heater and allow the tank to fill. Check for any leaks.
  11. Bleed Air: Turn on a hot water faucet inside your RV to bleed air from the system. Once a steady stream of water flows, turn off the faucet.
  12. Reconnect Power: If applicable, reconnect the electrical or propane connections to the water heater.

How Often Should I Drain My Water Heater?

The frequency at which you should drain your RV water heater depends on a few factors, such as the water quality in your area, the frequency of use, and the type of water heater you have. As a general guideline:

  1. Regular Use in Hard Water Areas: If you frequently use your RV and you’re in an area with hard water (water that contains high mineral content), it’s recommended to drain the water heater approximately once every 3 to 4 months. Hard water tends to cause mineral buildup more quickly.
  2. Occasional Use or Soft Water Areas: If you use your RV infrequently or if you’re in an area with relatively soft water, you might be able to extend the interval to once or twice a year.
  3. Annual Maintenance: Regardless of water quality, performing a thorough maintenance, including draining the water heater, at least once a year is a good practice. This ensures that any sediment buildup is kept in check and the system remains efficient.
  4. Visual Inspection: It’s a good idea to visually inspect your water heater periodically. If you notice signs of sediment buildup, like reduced hot water flow or unusual noises, consider draining it more frequently.

Remember that the goal is to prevent sediment and mineral buildup, which can affect the efficiency and lifespan of your RV water heater. Consulting your RV’s owner’s manual and considering the local water quality can help you determine the best schedule for draining your water heater.

Potential Problems and How to Avoid Them

While draining your RV water heater is relatively straightforward, a few issues might arise:

  1. Sediment Clogs: Sediment can clog the drain valve. To prevent this, consider installing a nylon drain valve or use a water softener to reduce mineral buildup.
  2. Leakages: Ensure all connections are tightened properly after draining to prevent leaks.
  3. Rust and Corrosion: If you notice rust or corrosion, it could be a sign of a deteriorating tank. Regular maintenance can help catch these issues early.

What to Do if I Can’t Drain My RV Water Heater

If you encounter difficulties while trying to drain your RV water heater, there are a few troubleshooting steps you can take to address the issue:

  1. Pressure Relief Valve: Before attempting to drain the tank, make sure the pressure relief valve is functioning properly. If it’s not releasing pressure, the water won’t drain effectively. Lift the valve to release any pressure and try again.
  2. Clogged Drain Valve: If the drain valve is clogged with sediment or mineral buildup, it might not allow water to flow freely. Try these steps: Gently tap the valve to dislodge any debris. Use a wire brush to clean the valve’s opening. If the clog persists, you might need to remove and clean the valve or even replace it.
  3. Using a Different Method: If you’re having trouble draining through the valve, you can try an alternative method: Disconnect the cold water input and hot water output connections. Use a pump to force air into the hot water faucet inside the RV. This might push the water out through the cold water input, effectively flushing the tank.Be cautious not to over-pressurize the tank, as it could cause damage.
  4. Check for Blockages: Ensure that the garden hose you’re using for drainage isn’t kinked or blocked. A clear, unobstructed hose is necessary for effective draining.
  5. Seek Professional Help: If you’ve tried these steps and still can’t drain the water heater, it might be time to consult a professional RV technician. They have the expertise and tools to diagnose and fix more complex issues.

What Happens if I Don’t Drain My Water Heater?

Failing to properly drain your RV water heater before winterizing your mobile home can lead to potentially serious issues due to freezing temperatures. When water freezes, it expands, and this expansion can cause significant damage to your water heater and the entire plumbing system.

Here’s what can happen if you don’t drain your RV water heater before winter:

  1. Freeze Damage: If water remains in the water heater tank during freezing temperatures, it can expand and crack the tank or damage its components. The result could be leaks, ruptures, or even a completely ruined water heater that requires costly repairs or replacement.
  2. Plumbing Damage: The water inside the pipes connected to the water heater can also freeze and cause pipes to burst or fittings to crack. This can lead to extensive plumbing repairs and potential water damage inside your RV.
  3. Inefficient Heating: Sediment and mineral buildup are more likely to occur when water is left in the water heater during winter. This buildup can lead to decreased efficiency when heating water, resulting in higher energy consumption and longer heating times.
  4. Additional Costs: Repairing or replacing a water heater, fixing burst pipes, and addressing water damage can be expensive endeavors. It’s much more cost-effective to take the preventive step of draining the water heater before winter to avoid these potential expenses.

To avoid these issues, it’s recommended that you thoroughly drain and winterize your RV’s plumbing system, including the water heater, before the onset of freezing temperatures. This process involves not only draining the water heater but also using antifreeze to protect the pipes and components from freezing. If you’re unsure about how to properly winterize your RV, consider seeking guidance from a professional or consulting your vehicle owner’s manual for specific instructions.

Do’s and Don’ts

Here are some important do’s and don’ts to keep in mind when it comes to draining your RV water heater, safety, preventing potential problems, and maintaining the overall health:


  1. Regular Maintenance: Do perform regular maintenance on your RV water heater. This includes draining it as recommended based on water quality, frequency of use, and your RV’s owner’s manual.
  2. Safety First: Do prioritize safety. Wear safety gloves and eye protection to prevent burns or splashing water. Always turn off the water heater and disconnect power sources before draining.
  3. Cool Down: Do allow the water heater to cool down before attempting to drain it. Hot water and steam can cause burns.
  4. Pressure Relief Valve: Do release built-up pressure through the pressure relief valve before draining to prevent hot water and steam from forcefully spewing out.
  5. Flushing: Do flush the tank after draining by briefly opening and closing the cold water supply valve. This helps remove sediment and mineral buildup.
  6. Inspect for Rust and Corrosion: Do inspect your water heater periodically for signs of rust or corrosion. Address these issues promptly to prevent further damage.
  7. Consult Owner’s Manual: Do refer to your RV’s owner’s manual for specific instructions regarding your water heater’s maintenance and draining procedure.


  1. Don’t Skip Draining: Don’t neglect draining your RV water heater. Sediment buildup can lead to reduced efficiency and potentially costly repairs.
  2. Don’t Forget Safety Gear: Don’t work on the water heater without safety gloves and eye protection. Hot water and steam can cause burns.
  3. Don’t Drain When Hot: Don’t attempt to drain the water heater when it’s still hot. Allow ample time for it to cool down to a safe temperature.
  4. Don’t Over-Tighten: Don’t over-tighten connections when attaching the garden hose or when working on the drain valve. Snug is sufficient to prevent leaks.
  5. Don’t Use Excessive Force: Don’t force the drain valve open if it’s stuck. Applying too much force can damage the valve. Instead, try cleaning or replacing it.
  6. Don’t Use Cold Water While Draining: Don’t open a hot water faucet inside your RV while draining, as this can create a vacuum and impede drainage.
  7. Don’t Drain in Freezing Conditions: Don’t attempt to drain the water heater or the plumbing system if temperatures are below freezing. Freezing water can cause damage.
  8. Don’t Neglect Winterization: Don’t forget to properly winterize your RV, including the water heater, before the cold season arrives. Neglecting this step can lead to freeze-related damage.


Regularly draining your RV water heater is a simple yet crucial maintenance task that ensures the longevity and efficiency of your RV’s plumbing system. By following the steps outlined in this guide, you’ll prevent sediment buildup, enhance your water heater’s performance, and continue to enjoy the comforts of hot water during your RV adventures. Remember, a well-maintained water heater contributes to a smooth and worry-free journey on the open road.

Related Articles

Similar Posts