Originally Posted by dave mosley
..... I tried the dry ice last night with little success.....

Unlikely to have worked, its much like removing seized nuts from bolts, if you only apply a single change of heat alteration your doomed from the start...
You need to apply 2 temperature variations in rapid succession to get a complete freeing clearance.

heat the nut till its red hot, then quench it in cold water, it will release its grip instantly....
how it works-> as the heat is applied, the heat in the nut slowly transfers to the bolt, the nut may be red hot but the bolt should not show any signs of the heat, once its quenched the nut shrinks rapidly onto the still expanding bolt and then the bolt shrinks down in size leaving a greater clearance.
Simplified -> your compressing the nut onto an expanded bolt

You need to apply the same principles to your stuck carbon.......

somehow.... apply heat to the carbon and dry ice to the pipe

Hotwater from the service could almost be enough if you crank it to MAX, the trick will be making it so it is constantly receiving a new supply of hotwater .... perhaps by placing your carbon into a larger PVC storm-water pipe with an end capped off bar for a dribble that the service can maintain the loss rate.

I'm sure you'll work it out

Yar, & this ere post be done without a sin'le drop o' rum passin' me lips

started with Impara Cadet #3 / Mosquito #245
& now Mosquitos #1182 & #1740