Photo of a Missoula heating contractor installing a combi boiler

Missoula Heating Contractors Play 20 Questions: Combi Boilers

If you are wanting to make your home more efficient and streamlined, replacing your boiler and hot water heater with one single unit, a combi boiler, can be a great idea!  It can be a bit stressful to consider a whole new piece of equipment.  Let’s have our favorite Missoula Heating Contractors answer 20 questions to get rid of the mystery, ease some worry, and see the great value it can add to your home! So without further ado, let’s jump into our HVAC version of 20 questions!

1.       What is a Combi Boiler?

A combi boiler is a piece of equipment that heats water for the sake of your heating system as well as your personal use.  This includes kitchen tap water, washing machine, shower/bath, and so on.  “Combi” is short for combination.  A combi boiler does the combined job of a boiler and a hot water heater.

2.       How Does a Combi Boiler Work?

A combi boiler works similarly to a tankless water heater, in that it creates hot water on demand.  It then sends that hot water to your heating system or to whatever tap is turned on at any given moment.  This means that you do not need to have a large tank holding hot water in your home.

3.       Does a Combi Boiler Have a Water Tank?

Combi boilers typically do not have tanks.  If you want to have a tank full of hot water in your home, you can opt for a storage combi boiler.  This option brings you the benefits of both a combi boiler and a traditional hot water heater.  The storage combi boiler has a cylinder that can hold hot water.  This helps when there is high demand concentrated in a certain time period. If you have a larger home, this can help your combi boiler system be more effective.

4.       Are Combi Boilers Energy Efficient?

In 2021, the United States Department of Energy passed legislation requiring residential boilers to have an Annual Fuel Utilization Efficiency (AFUE) rating of 82-86% or higher.  The specific percent varies depending on what type of fuel is being consumed to power the unit, as outlined in graph II.1 of the bulletin. This standard is the minimum required in order to be used in an American home.  A “good” AFUE rating is between 90% and 98%.  Many new combi boilers have an AFUE rating of about 98%!  Call your favorite Missoula heating contractor for specific information about combi boilers available for your home.

5.       Would it Be Cheaper to Replace my Current Traditional Boiler with Another Traditional One or a Combi Boiler?

Traditional boilers and combi boilers can have a pretty similar cost, both ranging from about $2,000 to about $8,000, depending on brand and fuel type.  What pushes the savings toward a combi boiler is the fact that it also does the job of hot water heater.  So instead of having to purchase 2 units, you only have the cost of one.

6.       I am Building a New Home; Would it be Cheaper to Install a Traditional Boiler HVAC System and Hot Water Heater, or a Combi Boiler?

If you are starting from scratch, installation can be done along with construction.  Thanks to BIM software, installation can go efficiently no matter which heating system you choose.  Costs for a traditional boiler are similar to a combi boiler.  If you go with a combi boiler, you will only have one piece of equipment to purchase because it also does the job of a hot water heater.  If you choose to go with a combi boiler, the cost of a hot water heater is basically eliminated.  Keep in mind that you will still need to have plumbing installed throughout the house, just not the hot water heater.  This means you will still have plumbing installation costs as part of the building project.

7.       Are Combi Boilers Cheaper to Operate Than a Traditional Boiler and Hot Water Heater?

If you are comparing a brand new combi boiler with a brand new traditional boiler and hot water heater pair, a combi boiler is typically more efficient and cheaper to run.  Odds are, however, that the boiler you are currently using is not brand new.  If your boiler was produced before 2021, it is probably even less efficient than a new combi boiler that you would replace it with. 

8.       Can I Replace My Steam Heat Boiler With a Combi Boiler?

Because combi boilers heat water for the rest of your home to use, it can only be used for hot water and not steam heat.  Transitioning your steam heat system to a hot water system will require more work and supplies, but IT IS POSSIBLE!  Contact Missoula heating contractors for advice and an estimate.

9.       Are Combi Boilers a Good Idea?

Many homeowners have found combi boilers to be a great investment for their property.  Combi boilers can be a great option for any size home but really shine in small units or homes with few occupants.

10.   Is it Best to Have a Combi Boiler or a Conventional Boiler?

There really is no simple answer to this question.  There are a number of factors that will make one or the other a better decision for your situation.  The size of your home, the number of occupants, your home’s current heating and plumbing systems, your gas or electric hookup, how much time and money you are prepared to invest, and what your goals are for your power consumption costs in the future.  To get a professional opinion on which would be better for your home, call your local Missoula heating contractor to discuss your variables and figure out your options. 

11.   Is it Cheaper to Leave a Combi Boiler on All The Time?

The answer to this question lies within your walls.  Your home’s insulation is often the reason your home does not stay as warm as you want.  Instead of leaving your combi boiler running constantly, you may need to plug up any gaps or weak spots in the insulation.

12.   What Are The Disadvantages of a Combi Boiler?

While Missoula heating contractors install combi boilers with confidence, all systems encounter problems with use over time.  The biggest drawback is that if something goes wrong with your combi boiler, you have 2 systems out of commission until you get it back up and running.  While you will still have running water, both your personal use water and any water running through your heating system will not be heated during the breakdown. This is why it is so important to have your combi boiler serviced every year to ensure worn-out parts are replaced before issues arise.

13.   What Are Common Problems with Combi Boilers, According to Missoula Heating Contractors?

Like any piece of equipment, issues arise with use.  Common issues that arise include leaking valves, odd noises, a pilot light going out, and low boiler pressure, among other things.  Most of these issues can be prevented with regular inspections and maintenance. 

14.   Since My Home Does Not Have Natural Gas Hookup, is There a Combi Boiler Option For Me?

Electrical combi boilers are a great option for homes without a gas hookup.  If you are off-grid or do not want your heat to be reliant on your electrical system, fuel combi boilers are available as well.

15.   Does a Combi Boiler Add Value to a House?

Real estate firms across the country say that updating a home’s HVAC system can increase the home’s value by 5-10 percent.  This can make a big difference if/when it comes time to sell.

16.   Are Combi Boilers Being Phased Out?

As you do research to determine what type of HVAC system will be best for your Missoula home, you may be finding articles talking about legal restrictions.  In the UK, gas boilers are not permitted to be installed in newly constructed homes built past 2025.  While this does not limit our options in the USA, some people are worried that the legislation is headed in our direction.  In the US, boilers are required to have a certain efficiency, but no type of fuel has been banned.

17.   How Complicated Would it Be to Retrofit My Home With a Combi Boiler?

If you are already on a hot water heating system, it really should not be difficult at all.  You may need a few new valves or adjustments.  If you are coming from a forced air heating system, you will have more work needed.  The ductwork is unnecessary with a hot water HVAC system and tubing for the hot water will need to be installed.  Contact a Missoula heating contractor for more information about retrofitting your Montana home.

18.   How Do I Get the Most Out of My Combi Boiler?

As with most heating systems, turning down the heat while you are out for the day can save costs as well as wear and tear on the unit.  If you are traveling, consider setting your thermostat between 55 and 60 degrees Fahrenheit.  If you work outside the home, consider getting a smart thermostat that will automatically turn down the temperature during your working hours and bring it back up to a comfortable temperature around the time you arrive home from work.  Keep in mind that if you have pets, this may not be the best option for their health.  Other suggestions are to adjust the controls for efficiency and schedule yearly maintenance for optimum performance. 

19.   Is a Combi Boiler OK for a Large House?

Combi boilers tend to get overwhelmed when there are several taps going at the same time. If you like the idea of a combi boiler but are worried about the unit not being able to keep up, there are a number of options.  One suggestion is to have 2 units installed, one on each end of the home.  Another idea is to use a storage combi boiler.  For more specific information and a Missoula heating contractor’s opinion about your specific situation, contact Garden City Plumbing and Heating

20.   Should I Get a Combi Boiler in My Missoula Home?

What is best for your home might not be what is best for another home.  Updating your home’s HVAC system will likely lower your power bills and make your home more environmentally friendly, no matter which system you update to.  

Call Your Local Missoula Heating Contractors! 

The folks at Garden City Plumbing and Heating are well-versed in installing most types of heating systems available.  Give us a call at (406)728-5550 or make contact through our website to help you figure out the best choice for your home today!