Rheem Prestige Furnace Error 45 Fix: Low Pressure Switch Replacement (DIY Guide)
Rheem Prestige Furnace – Error 45 (Low Pressure Switch Open) Fix Under $15 Our Rheem Prestige gas furnace decided to quit on us recently and locked out with Error 45 – Low Pressure Switch Open. No heat, just repeated startup attempts and the same code over and over. That flashing red 45 light was really bugging me 😅. For context, this furnace (and original pressure switch) had been in service for about 8 years when the problem showed up. I’m

