Customers insist a dripping tap is a ‘simple job’ – but they still call a plumber rather than do it themselves; here’s why …
First things first. How does a tap, any tap (faucet), work? Water gets to the tap through a pipe to the tap body. The water flows up inside the body to what is called the valve ‘seat’ – this is a hole with the top machined flat so that some form of valve (the bit that opens and closes) can sit on top of the seat. The valve connects to a handle and the operation of the handle controls the water flow out through the tap spout. Simples…
Traditional taps, ones you turn many times to turn on or off, were without doubt seen as a ‘simple’ device. When it leaked all you did was change the rubber washer right? Well, yes and no. If you promise to stay awake, I promise to give you enough inside knowledge to make you more competent than a huge number of plumbers. Just don’t tell ’em I told you!
Traditional valves have three items which cause problems. The washer which we are all familiar with, the slider o-ring and the stem o-ring(s).
Symptoms and causes
1 – your tap needs a lot of force to close off the flow or to stop it dripping, or it will not stop dripping from the spout. Typically this is a washer problem. Basically it has become worn so no longer seals against the seat
2 – your tap will not turn off or on or only a tiny bit. Typically this is a slider o-ring problem.
3 – your tap leaks from the top where the handle connects or the body. Typically this is a stem o-ring problem.
1 – changing the washer simply means removing the old one and installing new. BE AWARE – not all washers are the same. Size and their hardness differ. DO NOT use these very hard plastic things sold as washers. They are cheap and nasty and need real effort to close off properly. Instead insist on good quality rubber that you can just begin to squish between two finger nails. Any softer and they will last two minutes and any harder and they’ll be difficult to seal so difficult to turn off.
Make sure the centre hole is very similar too and lastly, when you install, make sure any raised lettering faces up rather than down towards the seat otherwise it will not seal. If it has any imperfections on its face then swap it or buy another as it will not seal properly.
2 – what actually happens here is something called hydraulic lock. Basically water slips by the big o-ring and get into the space needed by the mechanism. The cause of this can be A) that the O-ring has worn out or B) too small an o-ring has been fitted or C) that the washer has become very very worn and water gets past the O-ring. When the inner screw tries to drive in, the water already there cannot be compressed so the thing seems to lock up. When you change the o-ring, be careful to make sure the inner surface it moves against is both as smooth as a babies bottom and well lubricated with silicone grease. If it’s not then it will wear really quickly and you’ll be back to square one. Be careful to get exactly the same size o-ring. Too small and it will fail again in days and too large and it won’t fit and tear if you force it.
3 – typically the stem o-ring(s) becomes worn through lack of lubrication. What was an O shaped ring becomes a D shaped ring as it wears down and water escapes past it and out the stem. In poor quality taps this causes massive corrosion inside the tap ‘shroud’ (the pretty bit that hides the inner workings) often to the point where it falls apart if you try to remove it. Cleaning the surface the stem o-rings work against is always a challenge, but once it’s cleaned, well lubricated with silicone grease and new o-ring(s) installed it will go on for a very long time.
So the reality of fixing your own traditional taps is that it’s not always as simple as it seems at first glance. It’s very simply to write things like “change the o-rings” but the reality of finding correct sized ones is, lets call it a ‘challenge’. Many people carry the common kits available and they allow you to refurbish about 50% of traditional taps. However, if you come across some kinds regularly, then it really is worth taking the time to source the correct ones as you’ll be able to keep them working perfectly for generations.
One last thing. People often talk about ‘reseating’ the tap. What they mean is cutting a new seat by using a reseating tool. Firstly, unless you’ve let a tap drip constantly for, say, 6 months (in which case it will have worn the seat away and caused a groove just like water does in rocks) do not bother. The washer is capable of taking up quite a lot of difference. Also, unless your tap is of a certain age do not bother because few modern taps have the ‘meat’ (metal) in the seat area for re-working like that. Older taps were designed from the off to be refurbished and truly last. Modern taps have had that maintainability designed out of them to save money and increase sales. Manufacturers want to sell you a new taps they do NOT want you to repair the ones you have…
Any questions? Please ask via the comments below or via our Twitter feed @TapMedic