Leak at threads - Plumbing Forum

Leaksealer · 07-16-2010, 01:42 PM

Hello,

I have a 6 - year old 40 gallon Whirlpool gas hot water heater that is leaking at the cold water input threads. It looks like the installer cross threaded it. Can anyone recommend a way to repair this leak? I unscrewed it last year and applied a healthy coat of jb weld on it but it seems to have not done the job.

Thank you,
Jim

**havasu** · 07-16-2010, 02:08 PM

I would never recommend using JB Weld on plumbing pipes. You will need to disassemble the cold water "input threads" and fix the problem correctly. If the pipes are damaged from being cross threaded, replace them and use teflon tape to reassemble. Are you certain this was not caused because of failing to install a dielectric union?

**Chris** · 07-16-2010, 02:16 PM

Is your problem at the top of the nipple where the flex line is attached or the bottom where it attaches to the heater? If at the top you would need to remove both the flex line and the threaded nipple and replace both and if it is at the bottom you will have to replace just the nipple and maybe run a tap through the heater threads and reinstall with teflon tape.

Leaksealer · 07-16-2010, 03:02 PM

Quote:

Originally Posted by Chris

Is your problem at the top of the nipple where the flex line is attached or the bottom where it attaches to the heater? If at the top you would need to remove both the flex line and the threaded nipple and replace both and if it is at the bottom you will have to replace just the nipple and maybe run a tap through the heater threads and reinstall with teflon tape.

Hi Havasu & Chris,

There are no dielectric unions installed on this water heater. It is pex throughout the home and 18" of copper pipe at the water heater.
The heater was installed in 2004 so I am not sure if dielectric unions were required by code then. I suspect the threads are damaged beyond repair. Can I tap them out to a larger size?

Thank you,
Jim

**havasu** · 07-16-2010, 03:12 PM

No, you cannot change thread sizes by tapping, unless you cut off the old threads and start over. Since this would be a PITA, you can clean up the thread so it will accept another pipe without cross threading, provided you use ample amounts of teflon tape or Rectorseal, which is my favorite. It allows lubrication when threading, and contains sealing qualities, and is easy to remove if necessary.

Leaksealer · 07-16-2010, 05:14 PM

Quote:

Originally Posted by havasu

No, you cannot change thread sizes by tapping, unless you cut off the old threads and start over. Since this would be a PITA, you can clean up the thread so it will accept another pipe without cross threading, provided you use ample amounts of teflon tape or Rectorseal, which is my favorite. It allows lubrication when threading, and contains sealing qualities, and is easy to remove if necessary.

Thanks for the help Havasu,

There are no dielectrics installed on the hot and cold line and now it appears that the hot water side threads are leaking too. Does this problem seem to have been caused by not having dielectrics installed, and if so, do you believe rectorseal will seal the holes? The problem's been going on for about 1 - year on the cold side and I tried to solve it by using jb weld. Once again, thank you for the help.

**havasu** · 07-16-2010, 09:55 PM

Even though you are running PEX, the dielectric unions are probably not required, but are cheap and it will give you new threads to work with. You can get the hot and cold set of unions for ~$15.00. Put them on with some Rectorseal and it may just solve your problem.

Leaksealer · 07-16-2010, 11:45 PM

Thanks for the replies everyone.

I went out and purchased a new STATE 6 - year warranty water heater. It connected back together pretty simply but now I am having trouble lighting the pilot. I tried bleeding the system at the gas union but it still did not light.

Is there a way to bleed the gas valve directly?

Once again thank you for your help. I am learning a lot about water heaters today.

**havasu** · 07-17-2010, 01:27 AM

I posted a possible remedy on a separate thread which you had started. I feel bad you are having these problems, but to quote someone famous, "Been there, done that!" Once you finally get this up and running, please follow up with a reply on this forum so that others may learn ideas if and when they have the same bad luck!

Leaksealer · 07-17-2010, 01:58 AM

Quote:

Originally Posted by havasu

I posted a possible remedy on a separate thread which you had started. I feel bad you are having these problems, but to quote someone famous, "Been there, done that!" Once you finally get this up and running, please follow up with a reply on this forum so that others may learn ideas if and when they have the same bad luck!

I will definitely give you a briefing on the situation tomorrow.
Thank you for the help.