What's the Role of the Expansion Tank on Your Furnace?
Nowadays, few furnaces use steam to circulate heat, and cast-iron radiators were retired for more energy-efficient baseboard heaters. This switch was made possible by the invention of the expansion tank. The technology has replaced those primitive pressure control methods and is now an essential part of any heating system.
What does an expansion tank do?
An expansion tank balances the pressure in closed hydronic heating systems. It maintains a steady pressure level within the pipes so that they're not affected by potential excess. Since the pipes have limited space, the pressure will rise as the hot air or water takes up more room. Consequently, the furnace's weakest points can be damaged, resulting in a leak or even a burst pipe. An expansion tank alleviates the tension on the high-risk components of the heating system, significantly extending its durability.
How do they work?
An expansion tank is a small tank with a rubber diaphragm dividing it into two parts. One side contains the water, and it is attached to the heating system's tubing. The other side is dry and holds pressurized air, fixed to around 12 psi.
Most modern-day expansion tanks for hydronic heating systems use an extremely flexible butyl rubber or EPDM diaphragm. When the air side of the tank is pressurized, the diaphragm can conform to the tank's internal steel surface. The expansion tank's diaphragm draws back as the pressure levels rise. As a result, the air in the tank is compressed, allowing more water to penetrate. The process relieves the system's increased pressure and protects the pipes from damage.
The cost of an expansion tank
Expansion tanks come in various sizes, from two gallons to several hundred gallons. Depending on the capacity, the price range can also vary. Smaller residential tanks are typically affordable, whereas larger commercial tanks can cost hundreds of dollars.
The installation of an expansion tank
Installing a small residential expansion tank is a manageable task for a handy do-it-yourself homeowner. However, most local building codes mandate that a licensed plumber should install the tank. For an optimal result, you should always consult a professional.
How to tell if the expansion tank is working properly
Put your hand on the expansion tank and feel the temperature to see if it's running correctly. The top of the tank should be warm to the touch, while the bottom should be cool. If the whole tank is warm, it has almost certainly filled with hot water, which only happens when the diaphragm fails. In that case, you will need to replace the tank as soon as possible.
Get professional assistance
Of course, nothing can replace professional input. Find a company that offers maintenance, repair, and installation services for your area and have them do monthly check-ups. It's the most effective way to keep your furnace in optimal condition and avoid additional costs.
When you need heating or refrigeration service, maintenance or repair, call us at Affordable Comfort A/C and Heating 602-574-1205.
