Rheem 50 Gallon FVR NATGAS Water Heater 6YR 22V50F1 "front honeywell thermostat" Questions

...We're having record low sub-zero weather and need to get the batteries changed in our thermostat ASAP. The furnace wasn't working right this a.m. carefully pull out on the bottom front of ...

...Honeywell electronic gas control valve, and error code is 7 flashes.Probably you have power vent model.One manual from different company says: "Reset gas control using on-off button on front of ...