Repair or replaceyour furnace?

By the Welch Heating & Air team. Updated October 30, 2026.

The short answer

If your furnace is under 15 years old and the repair is a common part, fix it. If it is older, breaking down every winter, or the repair is a big one, start pricing a replacement.

That is the rule of thumb. Your house, your budget and how long you plan to stay all matter too. So here is the longer version.

When a furnace repair makes sense

A lot of no-heat calls are cheap fixes. We carry the common parts on the truck for a reason.

• Ignitor or flame sensor. The most common winter call we get. Usually a same-visit fix.
• Thermostat problems. Dead batteries, bad wiring or a failed thermostat. Not the furnace at all.
• Dirty filter. A clogged filter can shut a furnace down on a safety limit. Change it every one to three months.
• Blower motor or capacitor. A bigger repair, but on a furnace with life left, still worth doing.
• Control board. Can be pricey. On a newer unit, fix it. On a 20 year old unit, talk to us first.

If the furnace is younger than 15 years and has been reliable, a repair is almost always the right call. We will tell you that even when a new system would be a bigger ticket for us.

Signs it is time to replace your furnace

• It is 15 to 20 years old or more. Parts get harder to find and efficiency falls way behind new equipment.
• It breaks down every winter. Two or three repair calls in a couple of seasons is a pattern, not bad luck.
• Your power or gas bill keeps climbing and your usage has not changed.
• Some rooms are cold and others are hot. Sometimes that is ductwork. Sometimes the furnace just cannot keep up.
• A cracked heat exchanger. This one is not a judgment call. It can leak carbon monoxide. It gets replaced.
• Yellow or flickering burner flames, soot, or a CO alarm. Shut it off and call us.

The $5,000 rule

Here is a quick gut check a lot of techs use. Multiply the age of your furnace by the cost of the repair. If the number is over $5,000, replacing usually makes more sense.

A $300 repair on a 10 year old furnace is $3,000. Fix it. A $600 repair on an 18 year old furnace is $10,800. Time to look at a new one.

It is a rule of thumb, not a law. But it keeps you from pouring money into a system that is on its way out.

Why Tri-Cities winters change the math

Our winters are not Spokane winters, but we get cold snaps that sit in the teens for days. A furnace that limps through a mild December can quit the first week it really has to work.

If your furnace is borderline, the fall is the time to decide. Not 9pm on the coldest night of the year when every HVAC company in town is booked.

If you heat with electric, a new heat pump may also qualify for a utility rebate. We broke those down in our guide to Tri-Cities heat pump rebates.

What a furnace replacement looks like with Welch

• We size it first. Bigger is not better. An oversized furnace short cycles, wears out faster and leaves rooms uneven.
• You see options and prices up front. Usually a couple of efficiency levels so you can pick what fits.
• Ruud, Rheem and Bosch equipment. 95% and 98% AFUE gas furnaces, electric furnaces and heat pumps.
• Our own crew installs it. Old equipment hauled away. Financing available.

Learn more on our furnace replacement page, or if you just need it running again, our furnace repair page.

What we will not do

We will not tell you to replace a furnace that has years left in it. Rob Welch built this company on telling people the truth about their system. If a repair will do, we say so. If it is time, we show you why.

Need a straight answer on your furnace?

We service homes in Kennewick, Pasco, Richland, West Richland, Benton City, Prosser and Finley. Call (509) 820-3333. Our emergency line is answered 24/7.