DO you have a working LP Detector?
Check that it functions ------ take a BBQ lighter, hold it down by Detector and open it (no not light).
Does alarm go off? NO ----- fix/replace detector
YES .....
Go valve in LP at tank.
Then leave and come back in 20 minutes (no alarm).
Then lite off stove top burners on High on at a time (leave each one on), then next one until ALL are on High.
Do flames look same, are they strong steady, same height, did they stay same height or diminish as each was lit.
Diminished, lower height, flickering ...... LP Regulator may need adjusted./replaced.
Stove top burners all good......then with them on lite off water heater,
Check burners. Lite off furnace. Check burners. Lite off fridge.
LP Regulator should be capable of supplying 100% of propane appliances.