Arrived onsite to diagnose a no-heat issue. When the air filter was removed, the furnace operated properly. After reinstalling the air filter, the flames went out and the furnace displayed a code 57 (pressure switch open). I found a plastic hole cover missing, which separates the fan compartment from the burner compartment. After reinstalling the cover, the unit ran properly. The system only has one return, and I believe the insufficient return air was creating excess pressure and pulling air through the intake and exhaust venting. To correct this, I installed a 12x12 return grille in the mechanical room. The system is operating properly at this time. The tankless water heater’s display is broken. I contacted tech support, and they will send a replacement display to the customer once it is off backorder. I advised them to call us when they receive the part so we can install it. The water heater is functioning properly aside from the display. All work today is covered under Jerm’s 1
