I have a furnace mfd by Inter-City Products Corp. Model NUG5100BHB2. The combustion blower comes on but the furnace will not light. I was able to force it on by mechanically pushing the plunger off the microswitch with a screw driver on the vacuum switch connected with a hose to the combustion blower. Logic implies that the switch is bad however could it be a lack of vacuum for some reason. I am also unable to find a replacement switch on line.

First name change read

Inter City Products, Inter City Products Corp, Inter City Product Corporation (http://www.hvacplus.com/Inter-City-Products-450.html)

Second parts

ICP Heating Parts PAGE 1 (http://www.expertappliance.com/icp-heating.html)

Cheaper parts

New Upgraded Heil, Intercity Furnace Pressure Switch.(2-Wires 1-Hose): American HVAC Parts (http://americanhvacparts.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PRS1010897&Category_Code=New2008)

Always call to order and explain problem so you are sure to get the correct part.