The missing piece of the puzzle not referred to in your posting is whether the final orders in your divorce required your X to refinance to remove your name from the loan. If so, then you can file a contempt to enforce the order. If not, then, at best, you need to file a motion for clarfication.
This answer is provided for informational purposes only. True legal advice can only be provided in an office consultation by an attorney in your jurisdiction with experience in the area in which your concern lies.
If the decree or the judge doesn't say so, he does not have to refinance the home equity line of credit. Most decrees require that one spouse hold the other harmless on a specific debt. In this case your recourse is to sue him should you ever be held liable on this debt. The bank is under no obligation (and probably won't) remove your name as your name was a basis for granting the loan.
I'm assuming you got a fair property settlement in the divorce (especially since the judge is charged with making sure settlements are equitable and fair). Did you ever think that maybe the settlement's overall fairness was contingent about him getting that equity line of credit intact? Would refinancing to remove your name make the line of credit less valuable (a lesser amount, higher interest rate, etc)? If so, you should pay half the difference as an asset he received in the divorce now has a reduced value. In the alternative, reallocate who gets what AFTER the line of credit is refinanced at a reduced value.
He hasn't done anything to cause you to be liable has he? If not, what would you claim he did that is worthy of contempt? You want him to sell the house so you can sleep easier, but does that make sense in this economy? If you are ever held liable on the home equity line of credit file for contempt and under those circumstances he would likely be ordered to remedy the situation quickly and fully up to and including selling the home if that was the only option.
And yes courts do take contempt seriously. They don't always bring a hammer down on the first offense, but neither are they going to make your suffer financially over something he was to hold you harmless on. Hopefully you never need to file and in a few years when the economy is better (or his credit score is) he can refinance and get you off it. You can also inquire as to when you might be able to refinance the home equity line or what would be required to take you off. If he's able to do so and doesn't you might take him to court then and seek an order for him to do what is necessary.