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Serving Orange County

- SINCE 1981 -

Serving Orange County

- SINCE 1981 -


Hours: Monday-Friday 7:30-5:30PM
Saturday: 8:00-1:00PM


Saddleback Plumbing Heating & Air Blog

The Clicking Furnace: Here’s What Might Be Wrong

3D illustration of furnace

When you first turn on your gas furnace, you can expect to hear some clicking noises. This is the ignition system coming on to ignite the burners. But since you’re reading this, you’re hearing clicking noises at other times as well. Times when you didn’t normally hear clicking, and you’re concerned that you may need to schedule furnace repair in Rancho Santa Margarita, CA.

You’ve got the right idea. In general, out of the ordinary sounds from a furnace are warning of a malfunction of some kind that could enlarge into a full system failure or even a safety hazard. Clicking is one of the more common warning sounds, and it may also occur when the furnace is experiencing other troubles, such as the furnace not coming on at all. Below are some of the common reasons for the clicking furnace.

Motor bearings are wearing down or dirty

The bearings in the motor of the blower fan will wear down over time or start to become dirty and put more strain on the motor. Sometimes they’ll create a shrieking noise, but they can also start to make a clicking sound. If the bearings are dirty, technicians can clean and lubricate them to get them back to working well (this is a key part of regular maintenance). If they’re wearing down, technicians must replace the bearings before they cause the motor itself to burn out.

Faulty flame sensor

The flame sensor is a safety device (also called a thermocouple) that shuts down the furnace in case the pilot light goes out; this stops unburned gas from flooding out. The clicking sound may indicate that the flame sensor is faulty and shutting down the furnace no matter what. If the furnace isn’t turning on at all, this may be the reason. The thermocouple will need to be replaced. 

Faulty electronic ignition system

Modern furnaces don’t use standing pilot lights to ignite the burners, but an electronic ignition system. These igniters will often fail years before the furnace does and need to be replaced. The clicking sound is similar to the clicking you might hear when the gas burners on a stove won’t light: the igniter is trying to create the spark to turn on the gas jets, but is failing.

Gas supply trouble

This is one of the more serious issues that a clicking furnace can warn you about. The clicking noise means the igniter or pilot light isn’t getting any gas to ignite. The cause for this could be stuck gas valves, or it could be a gas leak in the line. We recommend shutting off the furnace at the furnace switch and calling us for assistance—you don’t want to inspect or tamper with the gas line and valves on your own.

Cracked Heat Exchanger

If the clicking sounds occur after the blower motor shuts off, they may be warning you that there are cracks in the furnace’s metal heat exchanger. Because these cracks can allow toxic gas to seep out of the furnace and into the air moving to the rooms, it’s something you’ll want professionals to investigate immediately. 

Call Saddleback Plumbing Heating & Air for fast professional repairs. Serving Orange County since 1981.

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