Tap tribulations! Another tap which won't turn on!

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Tap tribulations! Another tap which won't turn on!

Oct 1, 2017
Edinburgh Scotland
"The hot tap on the washbasin won't turn on" said Mrs J with an accusing look at me. This is a problem I've run into quite a number of times and not just in my own house. In fact the bathroom basin tap at my sister in law's has exactly this problem right now.

If you have modern quarter turn ceramic element taps then what I'm going to discuss here won't apply to you. However if you have the older type of tap which screws round by a few turns from off to on and vice versa then read on.

The oldest type of these taps are very simple and mostly only encountered as garden taps or stop cocks now a days. They are very simple with a rubber washer on the end of a screw threaded keeper which screws in and out to either block the flow of water - screw in - or out - to allow the water to flow. They have a gland on the shaft which comes out the top to the "T" handle and sometimes this leaks and sometimes you can nip up the gland nut to stop this. Here's what they typically look like:


Garden tap on the left, Kitchen/bathroom tap on the right. Both have the same type of "jumper" - why is it called a jumper? which looks like this


They are frankly so simple to deal with that if you are into fixing cars you'll have no problem fixing one of these - as long as you know how to turn your water off! So I'm not going to go any further with this type.

Unless you have quite a new house or have had recent upgrades done, you're more likely to have taps which look something like this:


and if you remove the shaped handle - usually simple if it's a plastic one but the metal type can corrode horribly and can be very difficult to remove. There's a wee screw under the cap.


Here I've shown the tap with it's handle removed and a spare jumper above it.

The type of jumper in this tap is the type I'm talking about here. What you find is that after a while, maybe years, the tap will only turn on enough to deliver a reduced flow. Then over time, this flow reduces until it won't flow at all. This is what has happened to many of this type of tap in our houses, and I've sorted out neighbours too.

So what's going on? Let's take a closer look at the jumper unit shown in the last picture:


Look to the left and you can see the splines on the end of the shaft which is where the handle fits. can you see also that there's a wee circlip just to the right of the splines? Lever the circlip off and you can press the whole inner part out to the right and once out you can screw the splined shaft off the plunger which has the main washer which shuts off the water:


Now we can begine to understand where the problem lies. Look at the right hand component. Just to the right of the hex shape can you see there's an "O" ring? Now look at the middle part with the male thread. See another "O" ring? Well, what happens is the "O" ring on the right hand part gets hard with age and doesn't hold the water back any more. This lets water past into the very restricted space between it and the "O" ring on the middle component. For the water to flow through the tap the right hand unit has to be able to withdraw towards the middle unit. Water between the two, with water being a liquid and therefore not compressible, stops this happening and prevents you turning the tap on!

The simple answer is buy the jumper complete and simply swap them out. However, after a while, the new unit will just repeat the problem. Ok, they're pretty cheap, I think about a fiver from the likes of Screwfix? but you have to turn the water off and physically go through the motions each time.

So, here's how I deal with it. First drill a small hole in the main body of the jumper unit here:


The size of the hole isn't important. I drilled a 3mm hole in this one but it just tends to be whatever small drill I've got that's nice and sharp. Now any water bypassing that first "O" ring seal can't hydraulic lock against the "O" ring on the male threaded unit. In everyday use the amount of water bypassing that first seal is very small indeed so you don't even notice it's now dribbling down and out from under the tap handle. So you can simply reassemble it and leave it at that. However I found some time ago that the "O" ring on the right hand unit is exactly the same size as the seal on the Quick release "Hozeloc" type hose connectors and you can buy packs of these "O" rings on ebay for absolute peanuts!


Renewing this seal seems to stop even the small amount of water which would have leaked if you don't change it. But even if it does leak, now you've drilled that hole the tap still isn't going to hydraulic lock - is it? Well mostly no it won't. But, I've come across a couple of taps where water had got down the threads between the two units and this was locking it up! I have noticed on later taps they now seem to drill a very small hole through into the threads on the right hand unit

Which you can see on the right hand in this image. I've got a number of spare complete jumpers which I've collected over the years and I now try to only use the ones with this hole. However it's much more common to find it's the "O" ring failing which causes the hydraulic locking. Oh, and while you're in there don't forget to fit a new washer will you. This one actually looked quite good and the tap wasn't dripping but when I dug it out it was soo perished and hardened that it started to fall apart:


Just a couple of other things to say. You should choose a really nice sharp drill and choose a slow drilling speed. I find my really really old Black and Decker on slow speed is just about right:


If you drill too fast, and especially with a drill that's not very sharp, I find the brass seems to get very hard and even if you then try a new drill in the same hole it just blunts the drill. Question - does brass work harden? Anyway, sharp drill, slow cutting speed and it seems to be fine.

And finally, if you have older type taps like these, you are more likely to still have a gravity system in your house? If so then go out and buy one of these kits:


The pointy rubber bungs are just so useful. Up into the loft and stick them in the supply pipes from your header tank and in seconds you've stopped water getting to the rest of the house. I stuck one in the supply to the hot water cylinder to do this job and it took seconds. You don't need to turn off isolating stopcocks and have the "worry"they may leak when turned back on. The hollow end can be used with the hose clip to stop cut ends of pipe if needed during alterations etc. When you've got the kit you just keep on finding other things you can use them for. Bung up the central heating delivery pipe and the expansion return and you'll find you can remove a radiator and it's taps with almost no loss of water - magic!

So, there you are. This morning I applied garden furniture oil to 3 benches and 2 tables in my garden. Had some lunch at about 2pm and was getting cleaned up after doing the tap by around a quarter past 3 all without really breaking sweat. Confident in the knowledge I may never have to look at that tap again, unless it ever needs another washer.
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