
What Are Combi Boilers?
October 31, 2019
You need a new boiler. While researching the topic you may have found some discussions about combi boilers. What are they? How are they different from standard boilers? Do you need one? Here’s a quick breakdown of this newer option.

Used in Europe for Years — Just Arriving in America
A combi boiler replaces your traditional boiler and hot water heater, allow you to heat your home and enjoy hot water with a single unit. This technology has been popular in homes throughout Europe and the United Kingdom for decades, thanks to its space-saving and efficient performance. Since boilers and water heater tanks only require replacement every twenty or years or so, many U.S. homeowners opt to stick with their traditional setup instead of trying something new. This has slowed the introduction of combi boilers to the U.S. market. However, newer models with improved heating efficiency are making combi boilers a very popular option now.
Heat Your Hot Water and Central Heating System with One Unit
With combi boilers, your hot water system and your heating system do not share the same water but are heated at the same location. Separate pipes enter the boiler and pass by the burner to be heated, after which they leave the boiler chamber and travels to your taps or baseboard heaters. A heat exchanger is positioned between the central heat and the hot water pipes inside the boiler and stores unused energy. When the thermostat calls for the pumps to start circulating hot water to your baseboards, leftover heat from the hot water side can be used to heat the rest of the home. You can use a combi boiler with gas, oil, or propane as the fuel source.
3 Top Energy Star Models
There are a number of quality combi boiler manufacturers on the market. Here are a few with Energy Star certifications:
- Bosch Greenstar Series
- ECR International Utica MAC Series
- Westinghouse WBRC Series
If you want to learn about more options to heat your Seattle area home, contact the experts at Best Plumbing. We will work with you to find the best system for your space, your water needs, and your budget. We have been the trusted plumbers for the greater Puget Sound area since 1968!