Arrived onsite to investigate intermittent heat on a Maytag propane furnace. They had a pressure switch close fault. They tried cleaning the condensate line and adjusting the heat registers. They only seem to have the problem when it’s cold and at night. When I arrived the furnace was working properly but eventually went out with the same code after I wired high fire. I checked combustion and it is within spec. I Checked the vent pressure and it within spec. I suspect that the pressure switches are getting weak and recommend replacing them. I provided and estimate and they accepted, we will call to schedule when the part arrives.
