I tried getting one back in 2008. All the part houses gave me the same story. I even tried looking for a brand x and could not find one to work with the vacuum. I was led to this supplierhttp://www.bouchillonperformance.com/BPEheaterValve.asp but went the cheap route instead. I went to lowes and for $5 I got a ball valve instead. I turn it on in the winter and off in the summer. A lot off guys used that method on their trucks down here so they could circulate air with the fan motor.