Is a refinace worth it?

[Sam Scott]

First mortgage, 230k, 5.125, ARM (40 year, about 14 years in), just reset in July (locked in may/June), up from 5%
2nd, HEL: 40k @ 3.75% (2 years into 10 year)
Property value, 300k

So that puts me right around 90% CLTV. The original mortgage was owner-occupied, but I since turned it into a rental. So, a refi would require an investment property loan.

I could pay off the HEL if needed, but not too keen given the good rate.

Is a refi worth it? Investment property loans are in the mid 4%, + fees, + I probably have to pay off the HEL to get to a reasonable LTV.

My current tenants have expressed a mild interest in buying the house next year. Nothing more than saying, "hey, we may want to" and I said, let's see where we are next year.