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Topic: Help removing rusty Aqua Hot exhaust pipe. (Read 728 times) previous topic - next topic

Help removing rusty Aqua Hot exhaust pipe.

Hello everyone,

We have a 1998 U320.  The Aqua Hot exhaust pipe rusted through at the 90 bend located in the middle of the run.  I have removed everything after that 90 degree bend.

The problem I am having is the short black pipe nipple (the one at the start of exhaust pipe where it comes out of the motorhome and runs parallel to the basement floor) is rusted to the black pipe 90 degree bend that comes out of the AH unit.  I could not budge it using a pipe wrench.  I am in the initial stages of hitting that joint with BP Blaster and letting it soak.

Does anybody have any suggestions or ideas on how to break a rusted threaded joint like this free?

Is is best to remove that black pipe 90 degree bend?  If so, what do you replace it with?

Thanks,
Chris

P.S. -  I do have the rig blocked off with tubular steel supports while I am working under there.

Re: Help removing rusty Aqua Hot exhaust pipe.

Reply #1 –
I removed everything including the elbow and the nipple that goes vertically into the AH unit and replaced with new black pipe pieces then transitioned to 1 1/2" stainless. I used the horizontal exhaust pieces as leverage to unscrew the vertical nipple from the bottom of the AH unit. Fortunately the vertical nipple unscrewed from the AH with little problem. If it doesn't come out readily, you will have to remove the burner and put the PB Blaster or similar in to soak from inside the chamber.
 

Re: Help removing rusty Aqua Hot exhaust pipe.

Reply #2 –
Bob,

Thank you for your reply.

I ended up removing all the old black pipe from the AH burner chamber as you did.  To do it I cut a piece of 4 ft steel conduit and using it as a breaker bar to remove the old black pipe assembly.

The original tail pipe section connected to the black pipe was so rusted that it collapsed and broke when I tried to use it as a breaker bar.

After looking at the sections of black pipe that were removed, they were pretty well fused together with rust.  I don't think any amount of PB Blaster was going free those up.

Thanks for the help.  We'll start with fresh black pipe, and we have a local muffler shop that will fashion a new tail pipe for us in a larger diameter.

Sincerely,
Chris