Not only is a malfunctioning furnace annoying to deal with when a homeowner is in need of heat, but it can also be a safety hazard. For example, if a furnace is fueled from gas and the pilot has issues, it can make it easy for carbon monoxide to get into a house. Basically, a gas furnace has to complete combustion to decrease the chance of high levels of carbon monoxide from getting into the air. In some cases, a furnace can be too worn out to make getting a repair worth the money. Depending on how badly your gas furnace is worn out, you might actually have to replace it.
Gas Constantly Leaks
You don't want to continue using a furnace that has been constantly leaking gas. Although gas leaks can be repaired in some cases, it can also mean that the furnace is too dangerous and worn out to repair. One possible reason why a furnace might leak gas is due to the valve being damaged, which can possibly be repaired. A malfunctioning burner can also play a role in a furnace leaking gas, but a new burner can be installed. However, if there are numerous reasons as to why your furnace is leaking gas and it is old, you will possibly have to get it replaced.
The Pilot Only Ignites Briefly
If you are never able to use the central heating system because the pilot doesn't stay ignited long enough for the heat to be produced, get it inspected to pinpoint the problem. The pilot orifice might be the problem and an easy repair, or the problem might be more complicated. For example, the pilot might only briefly ignite because the burner, gas line, valve, and other components are not in good shape. A sign that it is time to completely replace your furnace is if you have to constantly get repairs done so the pilot will function. A gas furnace is no good if the pilot doesn't ignite and repairs are unable to fix the problem.
The Power Has Gone Out
When a furnace gets to the point in which it doesn't turn on at all, it might be time to replace it. However, make sure it is plugged up and a circuit breaker isn't off before assuming that the furnace has gone completely out. If you have questions about furnace replacement, be sure to contact a local HVAC contractor