Should I Get A New Furnace?

by Erik North on January 14, 2011

boiler, furnace


Just look at that monstrosity.

This boiler was from an energy audit; it was installed in 1952 and was converted to natural gas but had previously run on coal. Yes, coal. And that is asbestos wrapped around the boiler.

The first question on the owner’s tongue was ‘Should I get a new boiler?’

Is a high-efficiency boiler or furnace going to help reduce heating costs? Are my heating bills going to lower due to investing in a high-efficiency furnace? Furnaces and boilers do contribute to energy efficient homes.

Important note:
Q. Did you know the key difference between a boiler and a furnace?
A. When one says boiler, it is a system that heats up water. If one says furnace, it’s a system that heats air.

Not a serious point but it is important to use the right terms.

So…Should I Get A New Furnace?

One of the first things my customers ask about is installing a high efficiency boiler. Sky-high energy bills, diminishing resources, and a healthy concern for our environment have brought a great deal of attention to the topic of home energy efficiency in recent years. Homeowners everywhere are struggling to spend less, use less, and pollute less without giving up the warmth and comfort they’ve come to cherish.

Efficiency – New vs. Old?

Older conventional forced-air furnaces and hot water boilers operated at very low efficiencies—some taking advantage of only half the fuel they burn. In an effort to curb this waste and pollution, the U.S. Department of Energy (DOE) instituted rigid new standards in 1992 that required every new heating unit to turn at least 78% of its fuel into heat. Manufacturers responded with models that meet and sometimes far surpass this.

The measurement for efficiency is called an Annual Fuel Utilization Efficiency (AFUE) rating. All furnaces now come posted with this rating, generally in the form of a yellow “Energy Guide” label.

Though most makers list their furnaces as “high-efficiency,” the DOE refers to units with an AFUE higher than 90% as “high-efficiency” and lower-AFUE models as “mid-efficiency.”

High Efficiency Costs More – Worth It?

With these high-efficiency products available, many homeowners are replacing their outdated boilers and furnaces. High-efficiency models represent only about $500 to $1,000 more in material costs than mid-efficiency units—and some utilities offer rebates that cover much of the difference. Given the fairly modest difference, qualifying for the available federal rebates (and whatever state programs may be available) makes sense if you’re in the market.

Should I Get A New Furnace – What’s The Payback?

A new, high-efficiency furnace can save you money in the long run. If your furnace or boiler is at the end of its service life and needs replacement, it pays to get a new, high-efficiency model. But does your furnace need replacement? Do you want a new furnace because your present one isn’t heating properly or is making too much noise?

You may find that simple repairs are all that’s needed. Furnace and boilers can be tuned-up, down-size the oil flow nozzles or add an outdoor reset. Also, if your furnace or boiler was installed since the DOE implemented their new efficiency standards, it is likely already decently efficient (80% or better AFUE).

The payback period depends on the price of the system, local energy costs, your climate, and the difference in efficiency between the old and new furnace.

There are many other simple household projects that have a better return on investment than a huge home system project like heating systems

The savings a homeowner would realize in replacing a mid-life heating unit would not likely justify the very considerable expense of a new system.

In Conclusion:

If you’re switching from an older oil boiler/furnace that’s at the end of its service life to a cheaper fuel (natural gas, solar, geothermal) then it makes perfect sense. However, if the boiler/furnace is less than 10 years old and you are keeping the same fuel (staying on oil) then the cost doesn’t justify the expense. A better route is maintenance and consulting your HVAC tech about simple repairs and adjustments that can improve efficiency.

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