新AC也有水，有時dripping pan 加 drainage 管。繼續用drainage 管？

https://azperfectcomfort.com/excessive-condensation-air-conditioner/#:~:text=Excessive%20water%20dripping%20inside%20your,excess%20water%20outdoors%20is%20malfunctions.

Part of drainage line may be dirty with bacteria.

https://whippleplumbing.com/blog/basic-average-furnace-repair-costs/#:~:text=A%20replacement%20draft%20inducer%20motor,ranging%20from%20%24250%2D%24450.

This price may be outdated. Exhaust inducer motor is easier/cheaper to replace.