Is that ALL blowers, or the blower that takes the burnt gases out, or the blower that sends warm air to the house?
If it is the blower that goes on with the gas ignition, then read:
http://www.heatpro.us/service/ignitor.htm
http://www.heatpro.us energy businessmen’s knowledge
Yes, you really have to find out the MAKE and MODEL to get good answers. There IS more than one machine made.