HomePlumbing TipsPlumbing: Threaded PVC pipe broken off inside a cast iron pipe. How do I remove it?
Posted in Plumbing Tips on 8th March 2014
plumbing tips

Plumbing: Threaded PVC pipe broken off inside a cast iron pipe. How do I remove it?
I have a threaded PVC pipe broken off inside a cast iron pipe. There is no part of the pipe sticking out enough to to grip the PVC. How do I remove the PVC without harming or replacing the cast iron pipe?

I’ve tried a screwdriver and hammer at the edge to attempt to rotate the remaining PVC but it’s in there very securely.

Any ideas? Thanks in advance.
This is for a 2″ sewage drain pipe. Can I block off the pipe and use the torch method, or will the sewer gas cause an explosion?

Best answer(s):

Answer by Corky R
The only piece of cast iron pipe I could think of into which a PVC pipe could be threaded, would be a coupling, or an elbow, which should be able to be removed from the rest of the pipe and replaced. There’s no effective way to get the PVC out of the threads on the old fitting to preserve the integrity of the threads and the connection. It will leak for sure if you do get it out.

Answer by Stuart H
Go to a plumbing supply house and get an internal pipe wrench.

Answer by BoxerPitRhodesian
if it is a waste line and not a supply line, you could use what i’ve always know as a fernco coupling. these are those rubber couplings with the screw clamps on either end. you can then leave the pvc inside the cast iron and attach a new piece of pvc.

I’ve also seen pvc removed with a dremmel attachment to grind the pvc away from the cast iron.

the first option here is easier and you won’t risk breaking your cast iron pipe which is brittle. However that coupling is not to be used under pressure, so if it is a supply line you can’t use it.

good luck with it.

Answer by btcbill
if the pvc is a smaller size, 1/2″, 3/4″, 1″, most hardware stores sell a tool to remove broken fittings. i’ve found it near the irrigation/plumbing supplies. i have used this tool often repairing irrigation systems.

Answer by Canman
very carefully cut one side of the pvc being cautious not to mess up threads. Then with screwdriver pry out. It is a little tricky and best to call someone if cast-iron is in wall cause fixing if you tear up the threads would be twice as expensive.

Answer by mort
if the cast pipe is 2in. or smaller just heat the cast and that will soften the pvc . then remove with a sharp knife or tool. I,ve had this happen to me.
caution!! open flame can cause pvc to ignite. i use a heat gun or hi-power hair dryer. have a extinquisher handy

Answer by Scott B
Torch it if its not a sewer line.

Answer by Willy r
get a gas hand torch and heat the galvanized pipe until the PVC gets soft take a screwdriver and use it to back the PVC pipe out

Answer by D R
i suggest useing a hacksaw blade . take a new blade and cut a slot out of the pvc pipe if the pvc pipe is 1 and 1 quarter or up to 2 inch.cut about a quarter inch slot out of the pvc the whole length of the broken pvc just go slowly so as not to damage the cast iron pipe
if the new pvc fitting that you plan on using is a male adaptor use teflon tape and Silicone when you reinstall the new connector just remember to go slow when cutting the old pvc fitting out of the cast iron.

Answer by mckindle26
Cut it with a small hacksaw being careful not to damage the threads or do what I would do. Get your blow torch out and heat it to the point where you can pry it out or grab it with needle nose and turn it out.

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