Responded to no-heat complaint on 8-year-old forced air furnace showing "tried to many times to fire" error code. Diagnosed plugged burners with rust buildup causing ignition failure. Replaced burners with new units carried on service vehicle, cleared condensate drains, and performed routine maintenance check on all components. System is now operating correctly. Advised customer to use only one filter in the 5-inch slot instead of the two that were installed.
