2009 Maytag gas furnace. Found concern with flame sensing system. Flames going out very intermittently. Tried cleaning it and still have issue. Recommended replacing flame sensing system. Showed options on page hm15. Customer chose hm15a. Completed repair and cycled unit. Unit is very clean on the inside and customer keeps up with filters. Performed combustion analysis. 39 ppm CO/ 8.4% O2/ 399 degree stack temp. All okay at this time.
