Refinancing a Heloc with an old furnace

[Rich Bultema]

I am looking to refinance an existing HELOC to increase the line of credit. The home has a 27 year old but still working furnace.

Will I get dinged on the appraisal enough to make it worth changing the furnace ahead of time? In other words, will my line of credit be limited by the old furnace by more than what a new one might cost? 

Im not otherwise concerned about it breaking since I have other ways to heat the home. 

also A/C is only a few years old. Not concerned with it.