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HVAC Forums => HVAC Help => Topic started by: Lainey on October 27, 2026, 03:23:28 PM

Title: Century Furnace 1989 model GSU 100M3N
Post by: Lainey on October 27, 2026, 03:23:28 PM
I have a very old Century natural gas furnace model #GSU-100M3N, serial #CN3D104 F3588 6198, that needs a gas valve. I'm waiting on the State to decide if they can fix/find the valve. System was installed in 1989. Since then I've only had to replace the thermo coupler and rebuild the blower. I know the unit needs to be replaced but have to rule out that it's fixable first. Any suggestions on a replacement gas valve? It's getting chilly in NE.
Title: Re: Century Furnace 1989 model GSU 100M3N
Post by: Admin on October 27, 2026, 05:00:13 PM
If you're able to, post a picture of the existing gas valve. Likely any universal gas valve would work.