How far along in the process are you that your nice loan people haven’t discussed this with you yet ?
Before they locked your pricing, they should have asked if you had a 2nd lien/HELOC/Home Equity Loan OR Solar lien.
Depending on how much equity you have, it may or may not affect your pricing.
Paying off a 2nd lien is considered a cash out refinance.
Early termination fee is usually $300
You have some choices:
1) A subordination so your 2nd stays in 2nd place and your new 1st replaces your existing 1st. Usually costs about $250 and takes several weeks.
Exact guidelines to follow. Depends on how much equity you have as to whether it will affect your loan pricing OR if it can be done at all
2) Pay off the 2nd with a cash out refi. Loan pricing could change (worse) depending on your equity. Pay early term. fee
3) pay the 2nd off with your cash. Close line. Pay early term. fee
OR
Pay off with your cash and leave line open.
Regardless of the current amount of your HELOC, there is a 2nd recorded for the maximum amount of your HELOC.
With some lenders this could present a problem.