Bradford White MITW40LGBN12 Water Heater Exhaust Blower not working

[Rick Crowe]

I have narrowed the problem down to the power exhaust is not working. I can not tell if it is the blower motor or selanoid switch. I have a second identical water heater which I used to swap out parts until I found the gerneral area that was bad. When I swapped the exhaust fan unit that fixed the issue. How can I determine if it is the vacuum switch, selanoid or the motor. The motor blades turn freely and I can not find any areas that look like any part was ever hot or even warm.

Still need parts so I can have two water hearters working again.

Thanks, in advance, for your help

[RegUS_PatOff]

... How can I determine if it is the vacuum switch, selanoid or the motor.

[Bullstok]

Did the blower ever start? Did the burner ever light or try to light? Did you ever get a error code from the gas valve? Swapping parts does not really narrow down much. It would be nice to have more details.

The Pressure switch tells if the blower is working and vent is clear. Use a manometer on the hose while the blower is on and compare to specs. Alternately, to manually test, remove the hose and lightly blow / suck into the pressure switch. You should hear a click. Remove the wires and test for continuity before and during the previous test. If the results of before and during do not change then the switch may be bad. You would still need the results of the first test if the pressure switch passed a manual check.

The temperature switch should have continuity. It only opens if the blower housing gets too hot.

[Rick Crowe]

The temperature switch continuity test ok, closed. The pressure switch works freely and the continuity was successfull. I wired the motor to a separate power source and the motor did not operate.

Green - ground

Black - hot

White - neutral

There appears no way to separate the motor from the fan housing to purchaes the motor only. Looks like the motor and housing with the fan have to be purchased as a single unit. I would just like to replace the motor everything else seems to be working fine.

Your questions:

Did the blower ever start? The water heater worked for 7.5 years with no issue.

Did the burner ever light or try to light? When I swapped parts I took the part from the non-working unit to the working unit next to it. The parts worked in the functional unit so I did not swap back to the non-functioning unitl. Only thing that did not work was the blower motor.

Did you ever get a error code from the gas valve? The gas valve does not have any error code read outs.

Do you know where I could but a replacement part, blower and motor?

If we could get the blower housing apart the motor is built by Jakel Incoporated, number 110533-00, 120V, 60 HZ, 2.3A 3000RPM Thermally Protected Class B INS

The water heater is a Bradford White Model MITW40LGBN12, S/N AD4553568.

[Rick Crowe]

I mean do you have a source for me to purchase the vent fan for my water heater?

I mean do you have a source for me to purchase the vent fan for my water heater?

[Bullstok]

The entire top is considered a unit and expensive. I do not deal in retail. Sorry. Possibly try a electric motor service shop. Keep in mind that this is what vents bad things away from your family. Please, Don't attempt to half-ass it.

Edit: I should have said the entire fan assembly is one unit, not nessesarily the whole top. Sorry.

Edited February 24, 2012 by Bullstok

[Rick Crowe]

Thanks for your help. I agree it should be purchased and installed back as a compete unit. I would not take any chance with fumes or gas build ups.

Thanks again, have a nice day.

[Samurai Appliance Repair Man]

Topic moved to the Water Heaters forum.