Thanks for the added advice. At first thought, it seemed like adding expense without much benefit. I'll definitely check on the price. Would I need to add water from an outside source or could I just keep a storage tank inside the garage as my supply line and refill as needed with a garden hose?
If you don't have a permanent water source, you could pressurize the system with a garden hose. All you need to do is maintain about 12-15 psi in the system and be sure to put a small hydropneumatic tank (bladder type Amtrol or similar brand) in the system. You'd just need to watch the pressure to be sure it was staying up. With a tight system, you should theoretically never lose any pressure. You shouldn't need to put antifreeze in it where you are either.
