NPE240A Error 003 *Diagnosis* Air intake filter - Clean Flame rod - Moderate Water inlet filter - Clean Heat Exchanger - Moderate Power supply properly grounded Incoming gas (before control) - 28.19inWC Incoming gas (after control) - Min - 3.5inWC Max - 10.5inWC 11.2V to ignition transformer No ignition Ignition transformer failure *Recommendation* - regulator on incoming gas - ignition/flame rod replacement - neutralizer on condensation line - expansion tank on cold inlet - routine flush and maintenance