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Polar Bear Air Conditioning & Heating Inc. Blog

What is a Boiler Expansion Tank?

Boilers in Washington DC are as common as forced-air furnaces: one of the pre-eminent ways we keep our homes cozy and warm in the nation’s capital. Boilers use heated water running through a series of pipes and radiators to provide heating for your home. They work extremely well in older houses which don’t have a duct system for forced-air furnaces, and also in newer houses which benefit from the comparatively simple heating process they use. The boiler’s expansion tank is a key part of that process, and it helps homeowners if they understand how it works.

In simplest terms, the boiler expansion tank helps control the pressure in the system. A boiler with too much pressure can cause a lot of problems, which makes the expansion tank an important safety feature. As the water heats up in the boiler, it expands which increases the pressure in the system. The expansion tank contains air, which unlike water, can be compressed. The air in the expansion tank thus acts as a kind of spring, absorbing the increasing pressure of the hot water without placing too much strain on the system.

Expansion tanks come in two basic types. The compression tank is a steel-walled model that uses a gauge to measure the overall pressure in the system. A bladder or diaphragm tank has a rubber bladder installed inside that can fill with water as the boiler does its job. There’s air outside the bladder on the inside of the tank to help it do its job.

Obviously whenever there’s problems with the boiler expansion tank, you need an expert to repair the damage. Trouble can come in the form of rust or a similar breach, or a damaged bladder if you’re using a bladder tank. If you own a boiler in Washington DC, then Polar Bear Air Conditioning & Heating Inc. is here to help. We can address your boiler expansion tank issues with courtesy and care, so don’t hesitate to give us a call today!

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