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steve4611 · Jun 24, 2009, 05:34 AM

I am attempting to install a dishwasher (first time) and having problems with the compression fitting. I was referred to use plastic tubing, as opposed to the conventional copper tubing. The problem is that both ends have a slow drip.

When I bought the dishwasher (used), it didn't have the male elbow installed, so I bought one at the hardware store and it came with the compression fitting. I am not over-tightening and I am pretty sure I installed the elbow correctly with teflon tape. I am not using teflon tape on the compression fitting, however.

After my first unsuccessful attempt, I tried to replace the male elbow and compression fitting with the same result.

Should I be using copper tubing instead, or does it matter for this application?

I am really scratching my head on this one, and open to all suggestions.

Thanks in advance for your help.

speedball1 · Jun 24, 2009, 07:58 AM

We have always uase 3/8ths copper to supply our dishwashers. Did you use the inserts, (see image) on the compression joints? If not, there's your problem. Good luck, Tom

steve4611 · Jun 24, 2009, 09:14 AM

Originally Posted by speedball1

We have always uase 3/8ths copper to supply our dishwashers. Did you use the inserts, (see image) on the compression joints? If not, there's your problem. Good luck, Tom

So does the insert fit inside or outside the plastic tubing?

massplumber2008 · Jun 24, 2009, 09:33 AM

Inside the plastic tubing... ;)

ballengerb1 · Jun 24, 2009, 09:44 AM

Yep, the plastic tubing is too flexible and collapses a bit so the compression can't keep a seal. That little insert maintains the rigidity and shape of the tubing.

steve4611 · Jun 24, 2009, 11:25 AM

Originally Posted by ballengerb1

Yep, the plastic tubing is too flexible and collapses a bit so the compression can't keep a seal. That little insert maintains the rigidity and shape of the tubing.

I will give it a shot and let you know tomorrow if it is successful. Very optimistic at this point though, thanks!

ballengerb1 · Jun 24, 2009, 04:07 PM

Steve, we all missed part of your question and did not answer directly about using copper. To be frank I have never used plastic to supply anything other than cold to an ice maker. Maybe one of the other guys can tell us if plastic is even rated for hot. Remember Tom in post 3 did say he used 3/8" copper, I think we all do.

massplumber2008 · Jun 24, 2009, 06:37 PM

Bob...

I tried to rate you, but not possible today. That was a great catch!

I would never recommend plastic water line for this application... ;)

I would install 3/8" O.D. copper refrigeration tubing or 3/8" compression SS braided hose.

Thanks...

MARK

mygirlsdad77 · Jun 24, 2009, 06:45 PM

I switched over to strictly ss braided hose a few years ago, what a blessing. So nice if you need to pull the dishwasher out for one reason or another. These work awesome if you have a 3/8 compression connection at stop(water shut off). I have seen a lot of 1/2 od copper used on dishwashers, so you will want to make sure your connections are the right size. If they are indeed 3/8, this is your best bet.

ballengerb1 · Jun 24, 2009, 07:29 PM

There you have it Steve, 3 plumbers and an old fool all say plastic isn't our choice. It's a short run so why take the chance with plastic.

steve4611 · Jun 25, 2009, 05:56 AM

Originally Posted by ballengerb1

There you have it Steve, 3 plumbers and an old fool all say plastic isn't our choice. Its a short run so why take the chance with plastic.

I didn't get around reading these messages until this morning. The good news is that I successfully made the connections last night using the copper inserts. That will at least get us operational, and result in a decline in the amount of times my wife will roll her eyes. :rolleyes:

The funny thing is I was at Sears Hardware originally to replace the older copper with new, after a tear in the line when I pulled the old unit out of position. Just so happened an retired pipe fitter was working and suggested the plastic option (didn't say a word about the brass insert). Due to my ignorance on the subject, it seemed like a great option at the time.

I will replace the plastic with the brass line like I should've done in the first place. Thanks guys for your input on this. First time user to this site and giving you all positive ratings for your much-needed assistance. Good Day!

mygirlsdad77 · Jun 25, 2009, 05:15 PM

Aw, the old plumber pipe fitter in the checkout line routine. Seems like they always want to give advice. Fact is, if they really knew what they were talking about, they would just stand there, not say anything, and laugh to themselves.

Glad you got the job done(and made the wife happy, that's what really matters in the end anyway). I would still suggest the stainless steel braided hose if you decide to replace plastic.