If your home has a “closed” plumbing system, then yes, you’ll need an expansion tank. You see, homes have either an open or a closed plumbing system. A closed plumbing system prevents water from flowing in the reverse direction (i.e., water won’t flow back into city lines once it enters your home’s pipes).
Additionally, does a 40 gallon water heater need an expansion tank?
Typically a 2-gallon expansion tank works with a water heater with a 40 to 60-gallon capacity and a psi of 40 to 50. A 4.5-gallon expansion tank is needed for larger water heaters, such as ones that hold 80 gallons with 80 psi.
Also question is, is expansion tank needed for code?
The California Plumbing Code (Section 608.3) and the California Mechanical Code (Section 1005.0) requires a thermal expansion tank, or listed equivalent, to be installed to water heating systems to relieve excessive building pressure during the heating process.
What can I use instead of a expansion tank?
What happens if you don’t have an expansion tank on water heater?
In a “closed” plumbing system, water can’t flow back into the city water lines once it enters your home’s plumbing. Now that might not seem so bad but if you don’t have an expansion tank, a closed system doesn’t give expanded water any route for escape, causing damage to your home’s water heater and plumbing.
What is the difference between an expansion tank and a pressure tank?
The biggest difference between pressure tanks and expansion tanks is in where they’re used. Expansion tanks are installed above a water heater and help to protect it when hot water expands. Pressure tanks are installed near your well pump and help to protect and extend its lifespan.
What size expansion tank do I need for a 40 gallon water heater?
General Guidelines for Sizing an Expansion Tank
| Water Heater Capacity | Supply Pressure (psi) | Expansion Tank Size |
|---|---|---|
| 40 to 60-gallon | 40-50 psi | 2-gallon |
| 40 to 60-gallon | 60-80 psi | 3.2-gallon |
| 80-gallon | 40 psi | 2-gallon |
| 80-gallon | 50-60 psi | 3.2-gallon |
What’s the purpose of an expansion tank on a water heater?
The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excessive water pressure. If water pressure gets to high it can damage valves in plumbing fixtures, joints in supply pipes and the water heater itself.