If you want something you can boil (just a very low bubbling, not a 'wild' boil), and not have to buy instant pudding, then make one of these mixes. You can use a low boil with these because they use powdered dry milk, not fresh milk.
Pudding Mixes
Vanilla Pudding Mix
3 c. nonfat dry milk
4 c...
I think it's the boiling. I make the same thing, but I never allow it to boil. Boiling often causes dairy proucts to separate.
Here's the recipe I use
Vanilla Cornstarch Pudding
2 c. milk
1/2 c. white sugar
3 TBL cornstarch
1/4 tsp salt
1 tsp vanilla extract
1 tsp butter
Heat milk...