Tape for screw joints on water connector to washing machine?

[Chris S]

Advice please. I am connecting a water supply hose to washing machine but getting a slight leak.

hose is brand new and the rubber seals inside the screw heads are undamaged. The screw part of the hose and the screw part of the washer are both plastic.

(1) Is the rubber seal at the end of the hose supposed to be sufficient to keep the joint water tight?

I do not think I am over-tightening the joint. If anything I may be under-tightening it as I'm tightening by hand and, at my maximum, probably could give it another 1/4 or 1/2 a turn.

(2) Is it good practise to use PTFE sealing tape on these screw joints? Or is the use of tape a sign of a poorly connection?

[TMC]

Never used ptfe on a washing machine or dishwasher hose connection at either end

If any sign of leak at hand tight I normally nip up just a bit with a pair of water pump pliers

Tony

[David Hansen]

On Fri, 25 Apr 2008 11:56:40 +0100 someone who may be Chris S wrote this:-

It is sufficient.

Hand tightening should be enough. If not look at the sealing faces.

Take a look at the fitting and think how it prevents the water coming out. The washer is sandwiched between two faces (one on the hose and one on the pipework fitting). Putting something on the thread is not going to do anything useful, as the assembly does not seal on the thread. If water is coming out then there is a problem with the washer or one/both of the sealing faces.

[George]

Turn the threaded plastic nut until the water stops leaking use mole grips lightly if needed. It will stop I promise ya.

[Dave Liquorice]

Short answer: Yes.

Long answer: Check that both side of the rubber washer are undamaged and that the faces it mates against are smooth and that the washer is properly seated into the hose end before you screw it on. Hand, bit more than just fingers, tight should be fine.

A this a new, untested, hose there is a possibilty that the crimp between the hose and fitting is leaking rather than the washer to valve. It might be hard to tell if the leak appears at the back of the "nut" rather than from the threads.

May hide the problem rather than curing it. The thread is there to force the washer against the end of the valve. That is where the seal is not in the threads.

[Roger Mills]

Yes - provided the sealing faces are good, and provided that there is nothing preventing the nut from screwing on far enough to compress the rubber washer. If the nut is bottoming on the threads before nipping the washer, use a thicker washer.

You may need to turn it a bit beyond hand-tight, using water pump pliers.

Tape is a waste of time. If water is getting past the washer, it will leak out of the back of the fitting even if you seal the threads (which are not meant to be sealed, anyway).

P.S. Check that the white plastic bits at each end of the hose are not cracked. I know it's a new hose, but these cheap tatty plastic bits are all too easy to damage!

[Ian_m]

No PTFE tape on plastic screw joints, all it does is deform the threads and water still leaks.

However I have had instances where a smear of Fernox LS-X on both sides of rubber washer and even lightly on the thread has finally sealed things.

One hose I couldn't seal was due to a blob of gloss paint on the rear of the thread of valve, due to when the kitchen was replaced ,that just lifted the plastic thread off the thread and leaked, Only obvious when I removed the valve for replacement.

Other than that you can get replacement ends for the hoses that jubilee clip on if hose replacement is not possible as some appliances the hose terminates inside the appliance in a manufacturer specific connector.

[Chris S]

Thank you to all who replied.