During the service, the furnace was found to trip on limit after the second stage of heating due to a MERV 12 filter. Removing the filter resolved the issue, and the furnace operated smoothly with a temperature rise within specifications. It is recommended to switch to a MERV 8 filter. Additionally, gas pressure decreased when multiple appliances were in use, suggesting a potential issue with the gas supply that should be addressed by contacting the gas supplier.
