If you have a boiler, you know it’s an important part of your household’s operation, as it heats the water that heats your home. But if you don’t know how to gauge your boiler’s fuel efficiency, it may be costing you a lot of extra money every month without you even knowing it.

That’s where AFUE ratings come in handy. AFUE, or “annual fuel utilization efficiency,” is a measure of how well a furnace or boiler uses its energy. For example, if your boiler has an AFUE rating of 75 percent, it converts 75 percent of the energy it uses into heat for your home. The remaining 25 percent escapes and is essentially wasted.

You pay, of course, for all the energy your boiler uses, not just the amount it converts into heat. Boilers with higher AFUE ratings convert more of their energy into heat, thus wasting significantly less. The type of fuel your system uses plays a role in its efficiency. Electricity-run boilers have the best AFUE ratings of all, but because of high electricity costs they still usually aren’t a wise economic decision. However, new gas-fueled boilers are also highly efficient.

Generally, newer boilers with higher AFUE ratings are more expensive. However, the better your boiler’s fuel efficiency, the more money you save in the long run. New, high-efficiency indoor boilers with sealed combustion have AFUE ratings of around 90 to 97 percent. So, with these systems, hardly any energy goes to waste. Not only is that good for the environment, it’ll also make a significant difference on your utility bills if you’re upgrading from a lower-efficiency boiler.

If you’re looking for a new boiler or deciding whether it’s time to replace yours, keep AFUE ratings in mind. And for your heating and air conditioning needs in the Sacramento area, contact All Year Heating, Air & Solar.

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).  For more information about boilers and other HVAC topics, download our free Home Comfort Resource guide.