How to Drain a Propane Water Heater: A Comprehensive DIY Guide

Draining a propane water heater is a crucial maintenance task that helps remove sediment buildup, improve energy efficiency, and extend the lifespan of your water heater. This comprehensive guide will walk you through the step-by-step process, along with detailed technical specifications and expert tips to ensure a successful and safe drain.

Technical Specifications of Propane Water Heaters

Propane water heaters are a popular choice for residential and commercial applications due to their efficiency and reliability. Here are the key technical specifications you should know:

  • Tank Capacity: Propane water heaters typically range from 30 to 100 gallons in capacity, with the most common sizes being 40, 50, and 80 gallons.
  • Drain Valve: The drain valve is usually located at the bottom of the tank and has a ¾ inch NPT (National Pipe Thread) connection, allowing for easy attachment of a garden hose.
  • Temperature and Pressure Relief (TPR) Valve: The TPR valve is typically located on the side or top of the tank and is designed to release excess pressure or temperature, preventing the tank from rupturing.
  • Gas Input: Propane water heaters require a gas input, usually ranging from 30,000 to 75,000 BTU (British Thermal Units) per hour, depending on the tank size and manufacturer.
  • Energy Factor: The energy factor (EF) of a propane water heater typically ranges from 0.58 to 0.67, indicating the efficiency of the unit in converting fuel into usable hot water.

Step-by-Step Guide to Draining a Propane Water Heater

how to drain a propane water heater

Draining a propane water heater is a straightforward process that can be completed by most homeowners. Follow these steps carefully to ensure a successful and safe drain:

  1. Turn Off the Gas Supply: Locate the gas supply valve on the gas line leading to the water heater and turn it clockwise to shut off the gas supply. This is a crucial safety step to prevent any gas leaks or accidents during the draining process.

  2. Turn Off the Cold Water Supply: Find the cold water supply valve, usually located near the top of the tank, and turn it clockwise to shut off the water supply to the heater.

  3. Connect a Hose to the Drain Valve: Attach a garden hose to the drain valve, which is typically located at the bottom of the tank. Make sure the hose is long enough to reach a suitable drainage area, such as a floor drain or the outdoors.

  4. Open the Drain Valve: Using a flathead screwdriver or by turning the valve handle, open the drain valve to allow the water to start draining from the tank. Be prepared for the water to be hot, as the tank may still be holding heated water.

  5. Open the TPR Valve: To speed up the draining process, open the TPR (Temperature and Pressure Relief) valve, which is usually located on the side or top of the tank. This will release any built-up pressure and allow the water to drain more quickly.

  6. Flush the Tank: Once the tank is completely drained, turn the cold water supply valve back on for a few minutes to flush out any remaining sediment or debris from the tank.

  7. Close the Drain Valve and TPR Valve: After the flushing is complete, close the drain valve and the TPR valve to prepare for refilling the tank.

  8. Turn On the Gas Supply: Slowly turn the gas supply valve counterclockwise to restore the gas supply to the water heater.

  9. Turn On the Cold Water Supply: Slowly turn the cold water supply valve counterclockwise to allow the tank to refill with water.

  10. Check for Leaks: Inspect all the connections, including the drain valve and the TPR valve, for any signs of leaks. Tighten the connections if necessary to ensure a proper seal.

Additional Tips and Considerations

  • Timing: It’s best to drain your propane water heater annually or every two years to maintain optimal performance and efficiency.
  • Sediment Buildup: If you notice significant sediment buildup in the tank, you may need to flush the tank more frequently or consider installing a water softener to prevent future issues.
  • Temperature Settings: After draining and refilling the tank, check the temperature setting and adjust it as needed to ensure the water is heated to the desired temperature, typically between 120°F and 140°F.
  • Safety Precautions: Always wear protective gloves and eye wear when draining a hot water heater, as the water can be scalding hot. Additionally, ensure the area around the water heater is clear of any flammable materials or obstructions.
  • Professional Assistance: If you’re uncomfortable with any part of the draining process or encounter any issues, it’s best to consult a licensed plumber or HVAC technician for assistance.


  1. How to Drain a Water Heater
  2. How to Drain a Water Heater
  3. How to Drain a Water Heater