How to Convert a Standard Water Tank to a Propane Tankless System?

Choosing the Right Propane Tankless Water Heater

When selecting a propane tankless water heater, consider your household’s water usage patterns. A typical household uses around 30-50 gallons of hot water per day. For a small to medium-sized household, a 4-7 gallon-per-minute (gpm) propane tankless water heater is sufficient. However, for larger households or those with multiple showers, a 7-10 gpm unit may be required. Ensure the unit is designed for outdoor use and compatible with propane.

Sizing and Installation

Proper sizing is critical to prevent the water heater from overheating and to ensure efficient performance. Calculate your total hot water demand in gallons per minute. For example, if you have a 3.5 gpm showerhead, a 2.5 gpm faucet, and a dishwasher that uses 2 gpm, your total demand would be 8 gpm. Install the propane tankless water heater as close to the water source as possible to minimize piping losses and ensure efficient operation. Use 1/2" or 3/4" copper or PEX tubing to supply water to the heater.

Venting and Freeze Protection

Proper venting is essential for safe and efficient operation of your propane tankless water heater. Use a minimum 3" diameter vent pipe, and ensure it extends at least 12" above the roof line to prevent condensation buildup. For freeze protection, consider installing an anti-freeze kit or winterizing valves on your supply lines. This will allow you to drain the water from the lines during cold weather to prevent freezing and bursting of the pipes. Additionally, consider installing a heat tape or thermostatically controlled heat cable on exposed pipes to prevent freezing.