It keeps dripping frequently. Redoing it up makes no difference. But why... do these things use O rings?
NT
It keeps dripping frequently. Redoing it up makes no difference. But why... do these things use O rings?
NT
Most of them use a standard tap washer.
And according to type, Type A has an o ring around the gland so they don't dribble when open. Type B has no o ring and does dribble when draining down. There is only a small difference in price so best to use the O ring type
Or fit washing machine taps as I did.
I use service valves, and pipe the output through the wall into the nearest drain or a suitable soak-away location. Saves messing about with hoses being draped through the house.
thanks, will fit a new tap washer when I next get there. It's type B.
NT
If it is like the old-fashioned ones I've seen it uses a washer of actual dimension about half an inch diameter which I have never seen in any kind of tap. You can use the 1/2" ball valve washers if you bore a hole in them. The real problem is that it is impossible to get heat resistant rubber washers in this size, and in a CH system they harden and/or disintegrate, and so fail quite frequently. I agree with those who suggest fitting a decent valve instead, but this may be impossible. For instance there is one in my boiler which could not easily be replaced without making a hole in the base or a panel.
BTW, the o-ring only stops it leaking round the spindle when the drain valve is open. When it is closed it leaks through the outlet and an o-ring has no effect on this. Leaking round the spindle can be prevented by having zero or less (vs. atomosphere!) pressure in the outlet hose, i.e. it goes smoothly downhill and is long enough to create some suction.
Sounds neat, but can you find a drain at the ch's lowest point?
And the thought of draining even a clean ch system into a soakaway sounds a bit gross.
I used a 40L trugg emptied a couple of times - not too much bother if you have underfloor access.
Well if you can attach a drain valve to that point, you can attach a pipe... so no different really.
So pipe from valve to drain. And if the drain is above the valve, you use a pump, or tap into the drain somehow?
I'm sure I'm missing something :-) Just that every house I've lived at the lowest CH pipe is well below the point of any surface drain. Obviously anything above the FF (flats etc) and you're all set.
Doesn't it smell for quite a while after you've drained the system? And kill foliage etc?
Each situation may be different. The last time I did it (solid floor downstairs - so all pipes were above the floor level), the original drain valve was on a horizontal pipe run to a downstairs rad in the hall
- probably a couple of inches above the skirting. There was a tee in the pipe with a down facing stub, and a drain valve on the end. So I took the valve off, and cut the stub back a bit and soldered on an elbow then fed into a service valve that was now below and parallel to the pipe. Drilled a hole through the wall above the drain gully outside, and piped that through to the service valve. Outside just needed a down turn in the pipe and 8" or so to direct the output at the drain. So to drain, just turn on the service valve with a screwdriver inside, and water went straight to the drain outside.
In this house they had already done something similar with a pipe below floor level taken through the outside wall, and terminating at a normal drain valve sticking out of the wall just below DPC level (which in this place is still a couple of feet above outside ground level). That's over a lawn, but obviously one can hose it to a another place outside if you want.
At a friends place he has all the downstairs CH piping chased into the solid floor. The service valves are again positioned outside, but this time only 3 inches above ground level by a flower bed. Not quite as easy, but still workable.
Even if so, then situation using a hose would be no better. The hose would still need to rise to reach a drain in that case.
Now obviously you can still drain the bulk of the system even if the drain level is higher than the lowest parts. If you really need to completely drain the lowest part, and its well below drain level, then you would probably need to drain to a condensate sump/pump style collector.
Can't say I noticed - if the system is relatively clean with inhibitor, you only get a small amount of sludge etc and lots of water to disperse it. Also a drain over a flower bed etc only need drain into it for the last little bit - you can run your hose outside for the bulk of the drain down, and only the last (by then well flushed) few litres would need to be dropped locally.
Last time I had to open one, I had the same problem, and it was leaking like mad as I was trying to drain it. It turns out it had been overtightened in the past, the washer had got crushed and turned almost to plastic. When I wound it all the way out, it just fell to bits.
that's what happened with this one too. Washer like a squashed pancake.
NT
why... do these things use O rings?
IMHO this happens because of loss of elasticity due to heat rather than careless misuse. It becomes harder to stop leaks until it finally disintegrates. There must be a (somewhat small) opportunity for someone to make some washers out of heat resistant rubber, such as is used for hot taps. Or should be.
I used a tapwasher. Stick it on, trim it all round with scissors, job done.
NT
Thanks for the explanation.
I think I'm still carrying the scars of draining the system here, which had turned into a sludge-like consistency. It now runs clear, but only after I used a lowest-point drain, removed every radiator, and flushed it several times.
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