Is there any way to join thwo different thread types without leaks? A friend gave me a beautiful Bosch dishwasher but the water connection is a problem. The dishwasher hose has a female connection the diameter of a hose bib, but with a finer thread. The adapter sold by Bosch does not thread onto the water connection under my sink - not sure if the thread is actually different or the little nipple inside the female hose connection is too long for my male sink connection. I've been to every hardware in the area looking for some way to piece all of this together with no luck. The closest I can come involves using a male hose bib connection to the female dishwasher line, with the obvious problem of the mismatched threads. Any suggestions would be so greatly appreciated.
Joining Different Thread Sizes
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Jeff Handy
Pro Handyman, NOT A Pro Plumber
Good clear pictures of everything will be required.
The more the better.
The more the better.
Mitchell-DIY-Guy
Well-Known Member
I recently installed a Bosch Ascenta 100 series dishwasher without much issue.
The supply fitting on the dishwasher was a standard ¾" MGH (male garden hose) fitting, just like the hose bibbs outside your home. The dishwasher required a 90 degree elbow, with a ¾" FGH on one end (like the standard end of any garden hose), and a ⅜" male compression fitting on the other, like this:
https://www.supplyhouse.com/Fluidma...ping&msclkid=199f35db1ba4104293db6a698c847f9c
Once that was installed, then the supply line (⅜" on both ends) screwed right on. The other end of the supply line was also a standard ⅜" female fitting. This screwed directly onto the new standard shutoff I Installed on the hot water pipe under the sink. Those shutoffs can be used with compression fittings OR with a gasket.
The kit below contains everything you need.
https://www.amazon.com/Kelaro-Unive...8908&sprefix=dishwasher+supply,aps,145&sr=8-7
Now, all that being said--if the built-in fitting on your Bosch will NOT accommodate this kind of elbow, something's amiss. I'd call Bosch tech support. Bosch makes a LOT of dishwashers for all markets, and maybe the required elbow fitting was supposed to come with yours and did not.
The supply fitting on the dishwasher was a standard ¾" MGH (male garden hose) fitting, just like the hose bibbs outside your home. The dishwasher required a 90 degree elbow, with a ¾" FGH on one end (like the standard end of any garden hose), and a ⅜" male compression fitting on the other, like this:
https://www.supplyhouse.com/Fluidma...ping&msclkid=199f35db1ba4104293db6a698c847f9c
Once that was installed, then the supply line (⅜" on both ends) screwed right on. The other end of the supply line was also a standard ⅜" female fitting. This screwed directly onto the new standard shutoff I Installed on the hot water pipe under the sink. Those shutoffs can be used with compression fittings OR with a gasket.
The kit below contains everything you need.
https://www.amazon.com/Kelaro-Unive...8908&sprefix=dishwasher+supply,aps,145&sr=8-7
Now, all that being said--if the built-in fitting on your Bosch will NOT accommodate this kind of elbow, something's amiss. I'd call Bosch tech support. Bosch makes a LOT of dishwashers for all markets, and maybe the required elbow fitting was supposed to come with yours and did not.
Above are the Bosch fittings, adapter female, adapter male, dishwashter hose. Below is the sink fitting and my cobbled solution that really isn't a solution. Hopefully these will help.
And, just in case someone is about to suggest it, changing out the dishwasher hose for a standard hose requires an enormous amount of taking apart and putting together. It can be done, but from what I've been able to learn it is not an easy solution. Thanks again for any help at all!!!
Thank you so much. This would be perfect, except that my dishwasher supply line has a female end rather than a male end. I wonder if the elbows can be found with a male end...
Mitchell-DIY-Guy
Well-Known Member
Wow, all things being equal: it's time to change that shutoff under your sink! All the chrome is gone and my guess it's pretty old...looks like trouble waiting to happen. Nip that in the bud.
I still say on things like this, you should get confirmation from Bosch tech support. Have the model number/serial number of the dishwasher handy. 1-800-944-2904.
Now you indicated in your first post that your fitting at the dishwasher is a "finer thread" than a garden hose. It's possible that it's an FPT fitting, in which case this would work:
https://www.supplyhouse.com/Sioux-C...ping&msclkid=87f01a6280c411e02b4045d02eb7de65
That would convert the FPT at the dishwasher to a MGT (male garden hose). Then you could use the conventional dishwasher supply kit or hoses as previously noted.
However something puzzles me. You indicate in your top row of photos, and correct me if I misinterpret them, that what you have is the Bosch supplied supply hose with a ⅜" compression on one end, a ¾" fitting on the other, and that second fitting looks like it is supposed to fit right into the fitting on the dishwasher itself. I don't think those fittings at the dishwasher require teflon tape; I think there's a gasket in the dishwasher, and the fitting itself is plastic and probably designed for hand-tighten. If that part of the hose doesn't fit into the fitting, Bosch supplied the wrong hose, or maybe the plastic end at the dishwasher got cross threaded.
Again call tech support to verify all the fitting sizes.
I still say on things like this, you should get confirmation from Bosch tech support. Have the model number/serial number of the dishwasher handy. 1-800-944-2904.
Now you indicated in your first post that your fitting at the dishwasher is a "finer thread" than a garden hose. It's possible that it's an FPT fitting, in which case this would work:
https://www.supplyhouse.com/Sioux-C...ping&msclkid=87f01a6280c411e02b4045d02eb7de65
That would convert the FPT at the dishwasher to a MGT (male garden hose). Then you could use the conventional dishwasher supply kit or hoses as previously noted.
However something puzzles me. You indicate in your top row of photos, and correct me if I misinterpret them, that what you have is the Bosch supplied supply hose with a ⅜" compression on one end, a ¾" fitting on the other, and that second fitting looks like it is supposed to fit right into the fitting on the dishwasher itself. I don't think those fittings at the dishwasher require teflon tape; I think there's a gasket in the dishwasher, and the fitting itself is plastic and probably designed for hand-tighten. If that part of the hose doesn't fit into the fitting, Bosch supplied the wrong hose, or maybe the plastic end at the dishwasher got cross threaded.
Again call tech support to verify all the fitting sizes.
Jeff Handy
Pro Handyman, NOT A Pro Plumber
What confuses me is how one hose can have three different ends on it!
One male, and two different female.
There has to be a second hose involved now, but I did not see that mentioned.
One male, and two different female.
There has to be a second hose involved now, but I did not see that mentioned.
I would replace what you need to so that you have consistent size/threads types. The more adaptors you use the more leaks you risk. Some later.
I use Bosch myself, and I don't recall any drama in connecting it. Certainly nothing was needed I couldn't get at the local hardware store.
Suggest you use Finish soap. mfg's used to suggest it too, as it does a nice job of protecting the door seals from leaking.
I use Bosch myself, and I don't recall any drama in connecting it. Certainly nothing was needed I couldn't get at the local hardware store.
Suggest you use Finish soap. mfg's used to suggest it too, as it does a nice job of protecting the door seals from leaking.
Jeff Handy
Pro Handyman, NOT A Pro Plumber
If you know the size of the dishwasher inlet, and the size of the supply stop outlet, just chuck that hose and start over.
You got a free dishwasher, so spend a few bucks on the correct hose and fittings.
You got a free dishwasher, so spend a few bucks on the correct hose and fittings.
The top three photos are of the Bosch adapter (the two silve ends) and the hose that is attached to the dishwasher (far right)
Jeff Handy
Pro Handyman, NOT A Pro Plumber
Then you should be posting pics showing all four hose ends, and labeling them as to what is what and which is which.
The whole things still makes no good sense to me.
Is the female connection to the Bosch inlet just regular hose thread?
And do you also need an elbow in there first?
The whole things still makes no good sense to me.
Is the female connection to the Bosch inlet just regular hose thread?
And do you also need an elbow in there first?
The 3/4" fitting fits perfectly into the dishwasher supply line, it is the 3/8 copression fitting that doesn't fit the shutoff under the sink. Not sure what the problem is because the 3/8" compression fitting from Lowes (bottom photo) screws on just fine.
Jeff Handy
Pro Handyman, NOT A Pro Plumber
One of the 3/8’s ends might be for a flare fitting.
Or some other similar size that is not 3/8 comp.
Or some other similar size that is not 3/8 comp.
