Who told you the heater needed replacing? Faulty heater will not stop dishwasher from working. It will still run but water will remain cold. Was it a proper service person. If yes, then tell them to come back & do the job properly. If not an experienced service person, then stop listening to family & friends who are only guessing and costing you unnecessary expense buying parts not needed. Water is not drawn in but flows in under it's own pressure when the inlet valve opens. The drain pump will not need to be primed just because heater was replaced. If no water is coming in, check tap is fully open and inlet hose is not kinked over. Inlet valve was working okay before the heater was changed. Get the person back to find out what they did wrong or phone a service company to come and sort out the problem.
Lincoln Appliance NZ, March 2014