Ultimate Heating Tune-Up Gas Heat: serviced and inspected gas heating system checking air flow, temperature rise, electrical, gas pressure, safeties, controls and limits, heat exchanger and venting. cleaned and checked system components to manufacturer specifications and performed combustion inspection. While running heat, it sounded like the inducer slowed down a little bit and it was drawing 1.4 A 1.3 it has runs was testing carbon monoxide And when the inducer made that noise, the carbon monoxide went up to 800. We went ahead and shut everything down. Make sure all the drains were cleared. Cleared out the drain trap and put everything back together and tested Started the system back up inducer now drawing 1.1 amp and carbon monoxide at 45%.