A combination boiler, often called a “combi boiler,” providess both space heating and domestic hot water (DHW) in one package to save space, and in a lot of cases, money.
Modern, high efficiency combi units like U.S. Boiler Company’s Alta Combi, are stainless steel condensing boilers with the addition of a built-in secondary heat exchanger to provide domestic hot water to a home or building. During the heating season, the combi boiler runs as needed to heat the house and provide hot water for showers, sinks, dishwasher, etc. During the summer months the combi boiler, is used only for DHW.
The Alta combi uses very little energy for two main reasons; it has a very high operating efficiency and it has a low internal water volume. This means that in the summer, when space heating is not needed, you are only paying to heat the hot water that you actually need, not a whole tank.
Cost-effective
The upfront cost of installing a combi boiler is generally very competitive to other alternatives. The single appliance typically costs less than installing a boiler and a water heater individually. For the same reason, the labor and materials required to install a combi unit will usually be less, too.
Property owners with limited mechanical space may appreciate the use of a high efficiency combi unit. These units can typically be installed in spaces not much larger than a broom closet. For this reason, combi boilers are popular with apartment and condominium owners, or homeowners that simply want to reduce the amount of space occupied by their mechanical system.
The best combi boiler in 2022
Shopping for a combi boiler is a bit like shopping for a car; there are a lot of options and it’s important to find the best value.
Alta Combi boilers are ENERGY Star rated and receive an “A” for efficiency. With a AFUE (Annual Fuel USE Efficiency) rating of 95 percent, 95 cents of every dollar you spend on fuel is turned into heat. Many gas-fired boilers and water heaters have lower AFUE ratings.
The Alta Combi is also one of the quietest boilers on the market. Its compact size and three-sided service access allow installers to hang the unit on a wall in a relatively small space, saving room inside your home. Also, if natural gas is not available at your location, installers can convert the Alta from gas to propane in just a few minutes, without any additional parts required.
The Alta Combi also provides virtually instantaneous domestic hot water response time. A five-year parts warranty and a 12-year limited warranty on the unit’s heat exchanger make the Alta Combi an exceptionally good decision.
The Alta Combi is a value-packed option for performance, long life, and energy efficiency, and it’s available in two sizes. The 136 MBH Alta Combi model was designed for the average American home roughly 2,000 square feet in size with two full bathrooms. The 200 MBH model can be used in larger residences.
Is a combi boiler the best choice for my home?
Providing hydronic space heating and domestic hot water production in one compact combi boiler is a big advantage, especially considering the low installation and operating costs. However, combi boilers are not ideal for every home and heating application.
Under most circumstances, combi boilers present no disadvantage when compared to a traditional water heater. The exception would be in families that take multiple showers and operate hot-water consuming appliances simultaneously. For example, if two showers, a dishwasher and a washing machine were running simultaneously.
If that kind of hot water consumption is common in your home, ask your professional home heating contractor which method of delivering domestic hot water is the best fit for your home.
You may find that one of the Alta Combi models is more than sufficient for the hot water demand in your home. If that’s not the case, the Alta is available in a heat-only model, which could be paired with an indirect-fired water heater for nearly endless hot water.
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