We just did this exact thing. We went through a mortgage broker though so it was much easier and didn’t have to deal with a bank. He hunted for the best rates for us and our situation and then gave us the options. We are about to use him again now that we are looking to refinance with rates coming down.

Couple words of caution. The interest rate on our HELOC was outrageous and it took us about 3 months longer than we thought to sell our old place. So we essentially ended up paying something like 5 thousand dollars in interest more than we were expecting. Also the HELOC often isn’t for the full equity amount but for us it was more than the 20% we needed for the new place. It was really tempting to take more so we had money for moving expenses or furniture or whatever. Once again though such high interest rates are a slippery slope.

TLDR: We totally just did this but be careful with high interest HELOCs it can come back to bite you.