One of rental units furnace had problems and the furnace people came over and fixed it, it was the switch. But the guys found another problem I need to do something about before long, I will need to replace a breaker down the road. The problem is it might be hard to find. The house was build in 1979 so the breaker box is that old. I do remember replacing several of the breakers a few years ago but he said it would not be a bad idea to replace the breaker for the furnace if I can find one. It's a 90 AMP 240 Volt Stab-Lok breaker. I've been looking online but can't find any "new" ones. I found several on Ebay and might have to get one. They are refurbished and I would rather have a new one but are these safe enough? https://www.ebay.com/itm/FPE-Americ...tablok-Circuit-Breaker-Warranty-/281713404725 If anybody has a better place to get them new please let me know.