My fan on top of my bradford white water heater model mitw40L6en13 went out. What kind of of exhaust/blower should i get to replace it? Thank you

This could be caused by a defective thermocouple,gas valve, limit switch, clogged spud or anything else. More information is needed. Gas equipment should not be serviced by novices. Save your life and property. Hire a professional!

Water heater is not identified and gas valve is not known.
Review options below:

1) Add a comment and describe what gas control valve is on the water heater, and model number from label on side of unit. Include what you have tried so far.

2) Try unplugging water heater and see if water heater resets.
Disconnect blower from gas valve, then plug blower in to see it it operates.
This will eliminate or include blower as suspect.

3) Open following link to download service and product manuals to help troubleshoot exact model.
http://www.bradfordwhite.com/documentation/residential/gas.asp

4) Open following link to identify gas valve.
http://waterheatertimer.org/How-to-adjust-temperature-on-water-heater.html#intelli

here's what Bradford White lists....
Burner Will Not Ignite
REASON REMEDY Excess primary air Adjust air shutter to reduce air supply -- if supplied No gas Check with utility Dirt in main burner orifice Clean orifice -- check for source of dirt and eliminate Dirt in gas lines Notify utility -- install dirt trap in gas line Venturi clogged Clean -- check for source of trouble and correct Pilot line clogged Clean -- check for source of trouble and correct Main burner line clogged Clean -- check for source of trouble and correct Defective thermocouple lead Replace with new thermocouple lead Defective thermostat Replace Defective magnetic valve Replace entire control Thermostat set too low Turn temperature knob to desired temperature Heater installed in confined space Provide ventilation by use of louvers in wall or door time for a service tech.

yes you can get a universal one at any hardware store[about 15$]. shut off cold valve at top of tank and drain tank through drain at bottom of tank.you only need to drain enough to get the water level below the t&p valve. you should use dope and teflon on the new threads of the valve to ensure no leaks. a big cresent wrench or pipe wrench will work to unscrew the valve in a counterclockwise direction

Your blower should run from before the heater lights until after it has shut off. Even if you're not using water, it will cool, and the heater will have to light to maintain temperature.

No the top thermostat is the first place I would start to replace. They run about 14.00 more than likely it isn't controling right. Turn power supply to water heater off and replace thermostat.

If you was getting scalding hot and then turning cold without tripping the thermostat it would be the top element working and the bottom one bad.
Bottom element good it will give you luke warm water for a while then gradually turn cold because it's heating the bottom of the tank.

Hope this will help you out.

You have a safety valve which is made to relieve pressure in the hot water heater in case it overheats. It may have developed a leak. Sometime you can lift up the valve and close it again a few times and it will reseal otherwise replace it. It's on the top of the heater with a small lever. Usually made of brass.

There really is no way to do this. If you put a cap you will restrict the air flow which will cause you to have problems with the water heater, same thing if you where to put screen on it. You can try enlarging the pipe to a 3 inch and see if that works. But 15 years in the trade nothing has been made to reduce the noise

It may just need a new pump coupling. Fairly inexpensive. I don't think you need to replace the whole burner.