Skip navigation

Serving The Fresno & Madera Area

70th Anniversary of Purl's Sheet Metal & Air Conditioning

Serving The Fresno & Madera Area


On Call 7 Days a Week


Purl's Sheet Metal & Air Conditioning Blog

5 Smaller Signs of a Dying Furnace


We’ve examined before the ways you can tell that you may need heating repair in Fresno, CA. As we keep moving through another cold winter in the Central Valley, you’ll want to know how to recognize all the potential indicators that your furnace is teetering on the brink of failing. 

Some of these signs we haven’t shared before—they’re the silent and small warnings that may not leap out at you. Today, we’re going to delve into these sneakier signs so you’ll know sooner to call our technicians to investigate your heating system. If there’s a problem, we will find it and see if a repair will fix it or if we need to replace the whole furnace because it’s truly at the end of its service life.

#1. The color of the flames from the burner

As long as your furnace isn’t a sealed combustion furnace, you should be able to peer into its cabinet and see the burner flames when the furnace is running. The flames should glow blue. If they’re yellow, it means gas isn’t burning efficiently. Not only is the furnace not living up to its full potential, it could be leaking carbon monoxide. Shut the furnace off and call us for help.

#2. Water leaking from the furnace

This seems extremely strange to people. Why would there be water in the furnace? If the furnace and the AC share the same cabinet (the setup in many homes), the AC may be the culprit. But water can leak from a furnace if there’s a blockage in its condensate line. You will need to have professionals clean the condensate line before the furnace starts to suffer damage.

#3. Constant thermostat adjustments

Are you and your family continually fiddling with the thermostat (whether manual or digital) to find a comfortable temperature? That shouldn’t be happening: the thermostat should be able to remain at a comfortable setting for long periods. The trouble could be with the thermostat, but these continual setting adjustments can also mean the furnace is losing heating power and just can’t keep up like it used to.

#4. Condensation moisture in your home

If you start to notice moisture appearing on the inside of your windows, walls, counters, etc., you may have a problem with the HVAC system, and the furnace is a possible culprit. What’s happening is trouble with the airflow that’s creating stagnant indoor air. Our technicians can look over the whole HVAC system to see where the issue lies.

#5. Corrosion on the furnace

Please don’t think of corrosion as something that just inevitably “happens” to a furnace and isn’t a problem. Corrosion is a huge trouble for a furnace, and when it does appear, it usually means the furnace is far too old and needs to be replaced. Corrosion has the potential to create safety hazards with a furnace, so please speak to expert HVAC technicians as soon as you notice this.

Contact Purl’s Sheet Metal & Air Conditioning for all your heating repair needs. Uncompromised Quality & Customer Service Since 1952. 

Comments are closed.