i hear water sloushing behind dash, How do you bleed cooling system and heater c

The norstar is self-purging so it has no bleeder. The problem may be a blocked purge line. There is a small diameter hose on the coolant tank near the top (Not the cap!). This is the purge line. With engine idling, pull the small hose from the tank. If there is no coolant flow it is blocked. If it is clear check the nipple on the tank for a blockage.