According to the U.S. Department of Energy, a boiler should last between 15 to 30 years. Based on our professional experience, that’s quite accurate – though boilers that last less than 20 years are cheap.
How Long Does a Boiler Last?
As with any other whole-house heating system, boiler durability depends on several factors:
Boiler Quality and Durability
The old saying, “You get what you pay for”, is often true. Higher quality products almost always cost more than those of lower quality. A boiler is subjected to a lot of heat and pressure, and boilers made with better materials and manufacturing processes will naturally last longer than others.
The quality of a boiler will quite often be reflected by the warranty – how long the manufacturer is willing to stand behind its product.
A review of several top boiler manufacturers like Weil-McLain, Utica, Slant Fin and others showed that warranties of the heat exchangers ranged from 10 years to a “limited lifetime” warranty, meaning that it is covered to the original, registered homeowner as long as they own the home. These same manufacturers’ warranties covered other parts of their boilers from 1 to 5 years.
So, just remember that if you plan on using a boiler for more than 15 years, don’t be afraid to spend extra money for a higher quality boiler.
In the long run, you will probably be glad that you did because you’ll have fewer repair issues along the way and won’t have to go through a boiler replacement hassle for another 5 to 10 years beyond the longevity of a cheaper unit.
Boiler Brand and Model
Every boiler manufacturer makes several boiler types with varying quality. We wish there were clear data on boiler longevity, but a comprehensive study has not been completed. However, through our experience and professional contacts, here is a good estimate of how long a boiler lasts. Remember, most brands range from cheap or average quality to good/bettter/best quality.
How Long Does a Boiler Last by Brands
|Lifespan in Years
|Weil Mclain Boiler
|18 – 35
|15 – 30
|18 – 35
|15 – 35
|18 – 30
|20 – 35
The Type of the Boiler
Here are common residential boiler types – the fuel they use, and how they operate. The chart answers the question – how long does a boiler last? Find your type, and you will have a general answer.
Most combi boilers are gas. Hydronic boilers are gas or electric. Steam boilers are almost always gas.
How Long Does a Boiler Last by Types
|15 – 35 years
|15 – 30 years
|12 – 28 years
|15 – 30 years
|15 – 35 years
|12 – 25 years
Let’s break down the chart in terms of how long they will last:
Standard gas boilers usually last a few years longer than high-efficiency (condensing) boilers.
The reason for this is because high-efficiency boilers recycle some of the flue gasses in order to gain extra heat. This increase in efficiency can result in a decreased lifespan, since the recycled gasses contain carbonic acid and are corrosive to some of the parts, despite the use of non-corrosive stainless steel inside the boiler.
Upfront cost vs operating cost: The other side of this is that the high-efficiency boiler will cost less to operate on a day-to-day basis, which may mean a long term savings.
If you have a steam boiler and wonder why it is failing, consider this: Steam boilers tend to form leaks inside the system because of the higher pressures involved. Those same pressures may also cause the boiler to work harder than a hot water boiler.
As might be expected, the higher pressure and extra wear in a true steam boiler will result in a shorter equipment lifespan. Generally speaking, a hot water boiler will last from 1 to 5 years longer than a steam boiler.
Note: Almost all of the boilers sold today are hot water boilers. Very few heat the water to boiling.
Here are the warranty lengths for some of the top residential boiler brands.
Boiler Warranty Examples
|All Other Parts
|10 or 15 Years
|3 or 5 years
*Navien offers different warranty lengths on various models.
Proper Sizing of the Boiler Affects Longevity
A boiler that is properly sized for your home will last longer than one that is the wrong size. If the boiler is too large, it will fire up to heat your home very quickly, then quickly shut off. This process, called “short cycling”, will keep repeating over and over throughout the heating system, resulting in far more wear and tear on the equipment than necessary.
If the boiler is too small, however, it will have to run a long time to get your home up to the desired temperature. If it is very much too small, it may actually never be able to reach the temperature on your thermostat during an exceptionally cold spell.
A boiler that produces the correct amount of heat for your home (measured in British Thermal Units, or BTU’s) will last longer than one that is either too large or too small.
Regular Maintenance of the Boiler
The final factor that determines how long a boiler will last is whether or not it has had regular maintenance performed on it. Unless you are very familiar with the inner workings of a boiler system, you should have this maintenance done by a professional HVAC technician once per year. Regular maintenance will prolong the life of your boiler and give these additional benefits:
- Increased energy efficiency
- Lower heating bills
- Less frequent breakdowns and repairs
- A manufacturer warranty kept valid
How do I know if my boiler needs replacing?
If you have a competent HVAC technician looking at your boiler system every year, he will probably eventually see signs that will indicate the need for replacement.
But you might also be noticing certain symptoms that may signal this situation. They include, but are not limited to:
- Frequent problems and/or repairs
- The boiler is making strange noises it hasn’t made in the past
- The boiler doesn’t maintain pressure
- Hot water not sufficient for daily needs: This problem applies to combi boiler systems that heat your home and provide your hot water.
These and other unusual symptoms should at least prompt you to contact your HVAC technician to see if it might be time to replace your boiler. If it is more than 15 years old, you might be glad to discover that the newer models will heat your home more effectively, maintaining balanced temperatures, and do it for a lower energy cost because of higher efficiency.
Can a boiler last 30 years?
Yes, a boiler can last 30 years or longer. To get 30+ years from a boiler, have it cleaned and serviced at least every 2-3 years.
Is it worth replacing an old boiler?
Yes. If you plan to live in your home indefinitely, a new boiler will lower your energy bills through energy efficiency. And it should run more reliably and be backed by a warranty.
Does a boiler need to be serviced every year?
No – every two or three years is sufficient unless you have very hard water that leaves visible mineral deposits in your water system. In that case a cleaning every year will extend boiler life.