I put some Blue devil head gasket repair in my 4.6L with a blown head gasket, it solved the problem, but now have no heat coming from my heater, we have 0/5 below weather and can't use the truck, the engin runs great , is this because of the Blue devil plugging up the water in the heads? or some other problem?

 

Did you disconnect the heater core hoses and by-pass it when you did the repair?

If not ... You've got a plugged heater core. *In additon to a head related repair.

BTW ... IIRC any product that is used for this type of repair includes (or should include) this in their instructions along with 1st flushing the cooling system and removing the thermostat.
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