1) First suspects include Honeywell icon gas control valve, loose-or-bad wiring, and dirty burner parts.
2) MITW50L6CX10 blower number is 239-39785-00. Blower is working, but communication between blower and gas control valve are suspect.
Water heater has 6 year warranty
Water heater was manufactured January 1999.
http://www.bradfordwhite.com/findaserial.asp3) Typical service manuals for M-1-TW-50 TTW series show how to test and replace Icon gas control.
Multimeter is required for testing.
Also shows how to clean burner parts and combustion chamber and air intake to catch up on regular maintenance.
http://www.bradfordwhite.com/images/shared/pdfs/manuals/46238-A.pdfhttp://www.bradfordwhite.com/documentation/residential/gas.asp4) 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.