I have a 100g 270000btu Bradford white eco-magnum series do you know why it makes a loud noise every time that it comes on??????

need to know model number of bradford white

It is pretty easy - make sure gas valve is open, change control know to pilot. Press the ignitor a few times and once pilot lights up switch control to warm or hot position.

See instructions by downloading manual for MI-403SF6BN from this site
Bradford White Water Heaters Built to be the best

bradford white blower . Sir this link will provide you with a variety of sources to buy the blower. The average is far below your quoted target. Since this is a nut and bolt with a direct plug or 3 wire assembly, bradford white blower 239 40614 00 . Here lies a different price point.


If this blower is out of warranty and its been running a long time. The value of the direct replacement is a far better choice to average, although more, odds; are to revisit it sooner than later without a direct replacement.


If you need help to do this job? It can be a do-it -yourself. Make sure the unit is locked out and give it a whirl. If not? The replacement is approximately 2/3 that of your suggested quote. The ball is always in your court.

Be safe. Carbon Dioxide does not discriminate, you never hear anyone from the cemetery complaining. If this is iffy. Get a technician. The extra 1/3 may justify the worth of a life investment. Fare. Well.

Probably cheaper to fix existing water heater.
The problem might be the power vent, or the power vent might be short cycling because the gas control valve is bad, or vacuum switch has gone bad.
Call Bradford White and get their recommendation for your specific model.
http://www.bradfordwhite.com/contact.asp
http://www.bradfordwhite.com/supportserv.asp
http://www.bradfordwhite.com/findaserial.asp

Bradford White is very good brand of water heater
Rheem, Richmond, GE are good.
I prefer the AO Smith, American, State, Reliance, Craftmaster. Kenmore, Whirlpool brand since air intake screen is located on bottom of unit and can be inspected and cleaned without removing burner.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Why is it always Rheem problems?
Every water heater problem is Rheem.
And Rheem doesn't post any service manuals, like the other two big manufacturers, AO Smith-American, and Bradford White.

Copy following link for troubleshoot by gas control valve.
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

Scroll up and find pressure switch heading among links.

You can install gas control valve yourself.
http://waterheatertimer.org/pdf/How-to-replace-water-heater-gas-valve.pdf

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Water heaters are a huge field of knowledge. Problem is not 100% clear.
There is a resettable thermal switch on the combustion door. This switch is round and has two wires that come from gas control valve. Thermal switch trips when combustion parts have not been cleaned and they cause overheated condition, or sensor reads temperatures above 180, or thermal switch has gone bad, or gas control has gone bad.
http://waterheatertimer.org/images/Whirlpool-Resettable-ECO-8.jpg
Add a comment with more information for continued help.

1) Bradford White support:
http://www.bradfordwhite.com/supportserv.asp

2) Bradford white mi403s6fbn is 6-year-warranty 40 gallon tank-type gas water heater with Icon electronic gas valve, and atmospheric venting.
Older models have the dial-type Robert Shaw or White Rodgers gas valve.
Open following link to see age of Bradford White:
http://www.bradfordwhite.com/findaserial.asp

3) Bradford white has 'product manuals' and 'service manuals' on following link:
Product manuals have general information and advisories that people can read about water heaters.
Service manuals are for plumbers and technicians, and do-it-yourselfers for testing and repairing water heaters.
http://www.bradfordwhite.com/documentation/residential/gas.asp

4) Typical manual for your product shows different gas valves, lighting instructions, and advisories, and troubleshoot checklist:
http://www.bradfordwhite.com/images/shared/pdfs/manuals/238-44219-00J.pdf

5) Add a comment with following information if you want specific help with servicing water heater.
What are you trying to reset on the water heater?
What are the symptoms, and what have you noticed, and what have you tried so far?
Which gas valve does your water heater have? Please open typical manual and view images of the three basic gas valves.
When was water heater last serviced and cleaned?
How old is water heater?

Take a moment and rate answer:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.

find out if it does the same noise with the venting disconnected

flue is overheating make sure outlet is not obstructed outside and if not that you feel a good air flow coming from it

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