Do I need to use a wrench to tighten these

Is the P213400 compatible with other gravity wall furnace brands

the 4074EGR is the standard crank arm assembly utilized for the M7415 series

If your media is compatible with FKM

Carrier HH18HV131 Limit Switch Do I need to useThe Carrier HH18HV131 Limit Switch is a critical OEM replacement part designed for precise thermal regulation in Carrier, Bryant, and Payne HVAC systems. Engineered as a high limit safety device, this automatic reset switch features a 130 30 degree operating range, meaning it trips at 130F to prevent furnace overheating and automatically resets when temperatures drop by 30F. Reliable thermal protection is essential for preventing damage to the heat