Is it dangerous to mix business-personal finances with LLC ?

[Kenneth Burke]

I recently refinanced the mortgage on my primary residence and combined the loans I took out to purchase my investment properties. I have three single family, long term rentals with separate LLC's and business accounts for each property. I am planning to make the mortgage payments from a combination of the business accounts and my personal account. Now that I am mixing finances, am I negating the protections provided from the LLC and opening my personal assets up to a potential lawsuit ? Does it make any difference if two of the properties and a portion of the third were purchased by taking a HELOC from my primary residence ?