Sometimes spending money can end up saving you money. In the case of furnaces and air conditioners this is often the case: Spending money can really end up saving you money in a short period of time. But beware: An inefficient furnace does not always need to be replaced, as there are some repairs and changes that can be made that might potentially help. For example, changing your furnace filters can help your system run more efficiently, as can making sure your humidifier is set to the proper level. Often, simple repairs such as replacing the pilot light with an electronic ignition or sealing the joints in your ductwork can end up doing the trick, thus saving you money and extending the life of your HVAC system.
If you really do suspect that you need a new heating or cooling system, the first step is to contact a reliable HVAC contractor to come and check it out for you. Remember, a furnace should last for about 25 years if properly maintained. So unless yours has been improperly installed, damaged or has faulty wiring, you should get many good years of use. So how will you know when it's really time to replace the furnace?
There are three main main reasons why you would need to replace a furnace:
1) It's Extremely Old and Inefficient
If you move into a home that was built in the 1960s or even earlier, chances are that it has an old boiler system or furnace. This doesn't necessarily mean that you need a newfurnace, but chances are that your system will need an overhaul to make it energy efficient for you.
2) The High Cost of Running Your Furnace
Find out which is least expensive in your area: gas or electricity, and try to use the least expensive resource for your system.
3) Heating Load
Heating load is the amount of energy required to maintain a steady 65-degree temperature indoors. To find out your heating load, you may want to consider contacting your utility company to perform an energy audit, which will help you figure out ways to make your home more energy efficient - and possibly save you from replacing the entire furnace or air conditioner. If you find that despite your efforts your furnace continues to work inefficiently, you probably need a new furnace.
Do the Math
If you replace your furnace with a 97% efficient system (look for an Energy Star furnace or A/C system and compare the AFUE and BTU levels), then you would cut your heating bills to around 20%. To see if it's worth spending the money, add up your fuel bills for last winter,then multiply that sum by 20%. Divide that figure into the cost of buying and installing the new system, about $3,000 or so, and you'll see how many years it will take to recoup your investment.