Just attempted to start my MasterTemp heater but it keeps shutting down. The service heater light is on along with three rapid flashing lights located within the ignition control module. Any thoughts or ideas what parts are required to troubleshoot and repair? The ignition control module label diagnostic indicator notes "3 flashes = ignition lockout". Not very helpful to me I have checked to make sure the heater is receiving natural gas, pump and filter running without obstructions. Any help would be greatly appreciated.