Your furnace sends signals when it is overheating: It makes humming noises, or emits a burning smell, or “short cycles” and stops working before it completes its normal on-off cycle.

You also may notice the air isn’t as warm as usual.

These are signs that the furnace is working too hard and, just like a person, will ultimately overheat and break down.

Fixes

A component may be worn out and need replacement. The average furnace works for about 15 years, but parts may deteriorate sooner.

However, other problems are less complicated and more likely.

• The easiest fix will be replacing a dirty filter – which also is a reminder to periodically make sure the filter is clean so you don’t overwork the furnace to an early death.

A dirty filter stymies airflow, which makes the fan work harder to move the air. This, in turn, causes overheating. New filters cost nothing compared to the price of a new furnace; clean or replace your filter whenever it gets dirty with debris, dander and dust. Otherwise, you will have to call a furnace technician.

If you wait too long to clean the filter, you will have bigger, more expensive problems: Dirt will eventually get through the filter and attach itself to the coil and other components.

This triggers problems for the heat exchanger and the blower. Now the system needs a professional cleaning. (This cleaning is a part of a technician’s to-do list of preventive maintenance.)

• Short-cycling also is a sign of a furnace in distress.

The constant on-off wears out components as well as boosts your utility bill.

Check your thermostat to make sure it is functioning properly, batteries are at full power, etc.

• Parts do wear out. One example: Electrical wiring in a furnace undergoes a lot of wear and tear.

Again, many of these problems can be averted with a thorough maintenance check before winter sets in.

Furnace problems in NYC? Premier HVAC services Brooklyn, Manhattan, Queens and Long Island.