The short answer
$100–$250
Only older furnaces with a standing pilot light have a thermocouple. It is an inexpensive part and a short visit, and a pilot that stays lit afterward is the proof it was the fix.
Typical industry ranges for Western Washington — not a quote. Your exact price comes upfront, before any work starts, and you approve it first.
What moves the price
Thermocouple or pilot flame
A pilot that will not stay lit can be a dirty pilot burner whose flame no longer heats the thermocouple properly. Sometimes cleaning the pilot is the fix.
The connection at the gas valve
A loose or corroded connection where the thermocouple meets the gas valve gives the same symptom as a worn-out thermocouple.
The gas valve itself
If the safety inside the gas valve is failing, a new thermocouple will not hold it open. Then the valve is the repair, and that costs more.
The age of the furnace
A furnace old enough to have a standing pilot is usually decades old. We give you the repair price and, if you want it, the replacement price, and you decide.
Pilot won’t stay lit?
On an older furnace that is usually the thermocouple, and it is a short visit. Exact price upfront.
Get My Upfront Quote60 seconds online · or call (253) 766-4822
Typical ranges at a glance
Typical industry ranges for Western Washington — not a quote. Your exact price comes upfront, before any work starts, and you approve it first.
Been told you need a new thermocouple?
Thermocouples are cheap, so they often get replaced on a guess. There is a simple meter test: heated by the pilot, a thermocouple makes a small voltage, and that voltage either is or is not enough to hold the gas valve open. Ask what it read.
We test it and show you the result before anything is replaced. If it tests fine, we say so.
Book a Second LookHow it works
- 1
Book online or call. Tell us what it’s doing, or what you were quoted. We diagnose it ourselves either way.
- 2
We test it and show you what we found. If the part tests fine, it isn’t the problem, and we tell you so.
- 3
You approve the exact price first. Nothing is replaced until you say go.
Where we work
From our base in Covington.
King County
Covington, Kent, Renton, Maple Valley, Black Diamond, Auburn, Enumclaw, Federal Way, Des Moines, Pacific, Algona, Burien, SeaTac, Tukwila, Issaquah, Newcastle, Snoqualmie, North Bend, South Seattle
Pierce County
Tacoma, Puyallup, Lakewood, Sumner, Bonney Lake, Lake Tapps, Orting, Buckley, Graham, Spanaway
Not on the list? Book it anyway and a technician confirms within 1 business hour.
Why homeowners call us
- You approve the price first. Exact price upfront, before any work starts.
- We answer 24/7. A technician reaches out within 1 business hour.
- 500+ jobs done by 4.9★ rated technicians. Licensed & insured.
- Fixed right, guaranteed. If it’s not right, we make it right.
Quick answers
What does a furnace thermocouple do?
It is a small metal rod that sits in the pilot flame. The heat makes a tiny voltage that holds the gas valve open. If the pilot goes out, the voltage drops and the valve shuts the gas off. It is a safety.
What are the signs of a bad thermocouple?
The pilot lights while you hold the button down but goes out when you let go, or the pilot keeps going out on its own.
Does my furnace have a thermocouple?
Only if it has a standing pilot, a small flame that burns all the time. Most newer furnaces use electronic ignition with an igniter and a flame sensor, and have no thermocouple.
Can I replace it myself?
It is one of the more DIY-friendly furnace parts, but it connects to the gas valve, and installed wrong it defeats a safety. If you ever smell gas, leave the house and call your gas utility from outside.
I replaced the thermocouple and the pilot still goes out. Why?
Then the thermocouple was not the fault. It is usually the pilot flame not reaching it properly, the connection at the gas valve, or the gas valve itself.
How long does the repair take?
It is a short visit. The swap is quick, and we then confirm the pilot holds and the furnace runs a full heating cycle.
How do I get my exact price?
Book online or call. A technician reaches out within 1 business hour, tests the part, and gives you the exact price before any work starts. You approve it first.
Ranges are for websites. Quotes are for you.
Book in 60 seconds — a tech reaches out within 1 business hour and your exact price comes before any work.
Get My Upfront Quote60 seconds online · or call (253) 766-4822
More from our site
Pilot light keeps going out? · Repair or replace your furnace? · Furnace repair cost · Furnace replacement cost · troubleshooting guides