Are you confusing the gas valve for a regulator? The regulator is at the tank or on the house, the gas valve is on the water heater. First of all, I've been in the gas business for 15 years and never have I heard of the cat theory. They would have to run around that water heater a super sonic speed to create a vacume strong enough to cause the pilot flame to pull away from the thermocouple. Some things you can look into are
1- the vent should terminate at least 3' off the roof line and if its within 10' off the ridge(peak), it should terminate another 2' above that.
2- its rare this time of year but possible, if the regulator froze it would stop the flow of gas to the water heater as well as any other gas appliance in the house. If everything else works but not the water heater its not the regulator ( which no plumber should be touchung as it is the gas companies property and they don't want inexperienced people touching their stuff).
3- make sure the thermocouple is positioned into the flame correctly. Only the top 3/8.
4- if it is a direct vent water heater(gets air from outside and vents outside), make sure inner pipe(exhaust) hasn't come apart or isn't fully connected as this will cause cross contamination of air and exhaust and to see if this is happening, light the water heater and watch the main flame. It will light as usual and within seconds start to roll and finally go out. If this happens fix the venting.
5- is there a roll out switch on the draft hood or by the burner tube? Check to ensure the venting is clear. If plugged or partially plugged the heat will not be able to go out the vent and will back up into the water heater flue causing that switch to trip. Some are auto reset and some are manual.
ask the plumber why he changed the part he changed and to prove its bad. As you can tell, plumber is a four letter word in my vocabulary. They've all been doing it for 30 years. Famous last words.
1- the vent should terminate at least 3' off the roof line and if its within 10' off the ridge(peak), it should terminate another 2' above that.
2- its rare this time of year but possible, if the regulator froze it would stop the flow of gas to the water heater as well as any other gas appliance in the house. If everything else works but not the water heater its not the regulator ( which no plumber should be touchung as it is the gas companies property and they don't want inexperienced people touching their stuff).
3- make sure the thermocouple is positioned into the flame correctly. Only the top 3/8.
4- if it is a direct vent water heater(gets air from outside and vents outside), make sure inner pipe(exhaust) hasn't come apart or isn't fully connected as this will cause cross contamination of air and exhaust and to see if this is happening, light the water heater and watch the main flame. It will light as usual and within seconds start to roll and finally go out. If this happens fix the venting.
5- is there a roll out switch on the draft hood or by the burner tube? Check to ensure the venting is clear. If plugged or partially plugged the heat will not be able to go out the vent and will back up into the water heater flue causing that switch to trip. Some are auto reset and some are manual.
ask the plumber why he changed the part he changed and to prove its bad. As you can tell, plumber is a four letter word in my vocabulary. They've all been doing it for 30 years. Famous last words.
