No Brainer? Use my HELOC to pay off my mortgage?

[prophei]

I need to plug in those numbers for myself, and it is an interesting point (to invest the money differently to end up ahead), though it still feels to me like you are a bit more exposed on that path. I know that the funds we regularly discuss have very solid records... but there are few things more guaranteed than simply paying off a huge debt. I am a bit on the fence with this one.

[Mother Fussbudget]

Why do you want to keep a big possible HELOC available?  Are you anticipating a big disaster you haven't saved for?  Do you have available savings in case of disaster?  Do you have any other debt?

One reason one might want to have a HELOC available is that once FIRE'd, it can be hard to qualify for a loan when you they have no debt, and show little to no 'income' from wages.  Hence, establishing a HELOC before reaching FIRE, and keeping it around (usually with a zero balance) in case of emergencies is a common practice.