Boilers lie at the heart of hydronic central heating systems, which use water to transfer heat to a distribution source, like a radiator, to heat a building. There are two main types of boilers: steam and hot water. Both boiler systems use piping to circulate this water or steam throughout the rooms of a building to keep the occupants warm.
An in depth discussion of boilers can get complicated and technical, but below we try to breakdown your boiler system and outline some of the major components of boilers, as well as certain accessories you can add on to any old or new system to make it run more efficiently.
Because the improper installation or operation of a boiler can result in catastrophe, we always recommend a professional installation of any boiler parts. But here we hope to make you a well-educated boiler owner, so you can confidently decide what steps to take next.
Essential Boiler Components
Steam and hot water boilers work differently and therefore have several different components, but the basic ideas are the same—heat up water and circulate the hot water or steam to warm up different areas in a building. Because the general functions are the same, there are a few common essential parts to all boilers:
Burner—The burner is what provides heat to warm up the water in the system. Boilers can run on natural gas, oil, or even electricity.
Heat Exchanger—The heat exchanger is responsible for transferring the heat from the burner to the water.
Supply Lines—These are the pipes that run from the boiler to the distribution points in the system. These lines run water or steam out of the boiler.
Return Lines—The water or steam that was sent of the boiler eventually cools and returns to the boiler to be reheated via the return pipes.
Circulator Pumps—Circulator pumps give your system life. They provide the force that pushes water or steam throughout your piping system.
Boilers also have features that help control their operation:
Water Gauge—The water gauge is a water level indicator and tells an observer the water level inside the boiler. It’s important that there is always at least some water in the boiler, even during periods of nonuse.
Pressure Gauge—The pressure gauge tells an observer how much pressure is contained within the boiler. There are both high and low pressure boiler systems. Residential steam boilers often operate at pressures as low as 0.5 psi.
Feed Check Valve—This valve is located inside the water supply line, and its purpose is to regulate the supply of feed water and maintain the water level inside a boiler. It is a one-way valve that prevents water from being returned back into the supply line.
Fusible Plug—This plug acts as a last resort safety feature for extreme temperatures in a boiler. This plug sits at the bottom of a boiler, and if water levels fall dangerously low it becomes exposed to the air where temperatures are high enough to melt the plug’s core, releasing pressure and steam from the system, and producing a loud noise to alert operators of the issue.
Blow Down Valve—The blow down valve is found at the lowest point on the boiler, as its purpose is to allow the drainage of sediments that build up inside boilers over time. These sediments would otherwise decrease water purity and unit efficiency, and can cause corrosion.
Safety Valve—Safety valves on boiler systems are used to release pressure when it rises above the maximum safe pressure limit, called the “set pressure”. These valves can be manual or automatic.
Accessories for Efficient Boiler Systems
Boilers can be retrofitted with additional accessories to help increase their efficiencies, and there are also cleansing processes you can schedule to keep your boiler clean. If you are installing a new boiler, or just want to make your existing boiler more efficient, consider utilizing any of these accessories:
Condensate Return System—Condensate return systems recover condensate and put it back into the system to reduce waste and increase system efficiency. There are two types of return condensate return systems distinguished by how they capture condensate: vented and pressurized.
Vented recovery systems work more efficiently on smaller, lower-pressure units, like most residential boilers. Pressurized recovery systems are better suited for larger, higher-pressure boiler systems.
Economizer—Economizers increase the energy-efficiency of boilers by preheating the water to just below its boiling point. They use the hot exhaust gases produced by the boiler to preheat the cold water that is continuously added to the system.
You can have this type of device fitted onto your system at any time.
Continuous Blow Down Accessories—This is also called surface blowdown or skimming and is the process of removing water impurities from the top of the water in a boiler. This process is supplemental to the cleaning done by draining through the blow down valve, and helps maximize water cleanliness by reaching impurities that are buoyant and float.
You can install either a pipe that enters the steam drum at the normal water level, or a more complex skimmer arrangement that floats and swivels to collect and remove impure materials.
Boiler Water Treatment Systems—Water treatment processes remove harmful impurities from boiler water that would otherwise cause corrosion, scale, or foaming. This process can be performed on water both before it enters your system, and once it’s already inside.
Internal treatments include balancing PH levels and adding chemicals to prevent foaming. External treatments clean the water before it goes into your boiler, removing any impurities before they have the chance to cause any damage.
Looking to Increase the Efficiency of Your Boiler? Pro HVAC Service Can Help!
Boiler systems can run for a solid 30 years if they are properly maintained. To increase the lifespan of your boiler, call Pro HVAC Service today at (844) 769-5995 or fill out the form on the right for free quotes on services near you.
We partner with a nationwide network of HVAC contractors who are equipped to help you with any boiler retrofits or installs. Our goal is to connect you with reputable service providers who will help make your boiler system as efficient as possible.