Gas tech here. As others have mentioned before about the rod , this can be the case , typically you can also tell this is happening because your gas bill will go up since the tank will keep needing to run in order to be satisfied, but if you notice your gas bill going down in terms of therms used , it could possibly be the thermostat itself is bad and is stuck or broken , basically when this happens the burner won’t stay on long as the heater thinks it’s at the desired temp too soon, you can replace the thermostat typically you buy the entire control , and replace it
Drknss620 t1_itvvr5t wrote
Reply to Water Heater Suddenly Only Produces Warm Water by PernPorson
Gas tech here. As others have mentioned before about the rod , this can be the case , typically you can also tell this is happening because your gas bill will go up since the tank will keep needing to run in order to be satisfied, but if you notice your gas bill going down in terms of therms used , it could possibly be the thermostat itself is bad and is stuck or broken , basically when this happens the burner won’t stay on long as the heater thinks it’s at the desired temp too soon, you can replace the thermostat typically you buy the entire control , and replace it