Burnham ALP105 gas boiler repair

heatingFun

My 7 years old Burnham ALP105 gas boiler stopped working for us few days ago. It worked 2 weeks ago. The fault information from the boiler screen are these:

Active faults,
Hard lockout 19
Purge rate providing failed
Possible cause: misswired fan power harness,
Misswired fan speed harness,
Defective fan


From its service manual and installation manual, I found the following for above information:
E 19 --- MCBA return sensor detected temperatures in
excess of 200°F for an extended period of time

--Lockout Number :: 19, Purge rate proving failed -- condition::
Blower is not running at Purge rate
when it should or fan speed signal not
being detected by Sage2.1.-- Possible Cause::
• Loose connection in 120 VAC fan wiring.
• Loose or miswired fan speed harness.
• Defective fan

A plumber from a company told us we need to replace the "fan motor assembly". The total cost will be about $1700.

Did some research and found this possible parts: http://www.supplyhouse.com/Burnham-101527-01-Blower-Alp-80-105

I am asking your help for the following questions:
1. Is that the right parts?
2. Do we need to replace the entire thing or just a fan replacement will be enough?
3. Is it a possible job for a handyman?

Thanks,