I need to remove my old kitchen sink and move some of the pipe work. Will I have to drain the hole system to do this ? (I think I have a Y Plan system) If not what do I need to do to stop the water?
I will also a some point soon need to move a rad and pipework will I have to drain down for this?
Have not done much work on CH so easy to follow instructions would be great.
Thanks
Paul
The water which comes out of the hot tap of your kitchen sink is (or should be!) entirely separate from the water in your heating system. The closest they get to each other is inside the hot water cylinder - where hot water from the boiler flows through an internal coil/heat exchanger, and heats the domestic hot water without the two lots mixing. So, to work on your sink, you *won't* have to drain the heating system. But you *will* have to stop the hot and cold water flowing to the taps.
The cold tap is probably straight off the mains - in which case you simply need to find the main stop-c*ck and turn it off. Water may still come out of the tap for a bit after turning off the stop-c*ck, because it will be draining back from the pipes which go upstairs. So give it time to stop before disconnecting the pipework.
When you open a hot tap, water flows from a cold header tank (probably in the attic) into the *bottom* of the hot water cylinder, pushing water out of the *top* connection of the cylinder - which feeds the taps. So, to turn off the hot water, you need to stop water flowing from the header into the bottom of the cylinder. Hopefully there is a tap or gate valve in the feed pipe which goes to the bottom of the cylinder. If so, turn it off. If not, you'll either have to tie up the ball valve on the header, and let all the hot water run away until it empties the header and stops running - or you'll have to interrupt the flow in some other way. One possibility is a cork in the outlet fitting at the botton of the header tank. Use a tapered one, which leaves enough to get of hold of to remove it when you've finished.
You will have to partially drain the heating system for this. After turning off the whole system at the FCU, drain the radiator, as follows: Turn of both radiator valves. [If one is a thermostatic valve, remove the head and fit a positive stop cap which holds the pin firmly down at all temperatures]. Partially undo one of the union nuts which joins its valve to the tail (the bit screwed into the radiator). Catch the water which comes out. You will need to have handy a bowl or bucket big enough to hold the entire radiator contents - but you'll need smaller containers which will slide under the valve to actually catch the water - I find aluminium take-away food containers good for this. You'll also need to protect carpets etc. with plastic sheeting and old towels - black stains from central heating water are almost impossible to remove! Work on both sides of the rad (one side at a time) until no more water comes out, then disconnect the union nuts completely. You can then lift the radiator off its brackets.
You still have to drain the pipework before you can work on it!
Besides the large cold water header tank, you will have a smaller fill and expansion tank which feeds the primary circuit - that's the bit you want to work on. Put corks in the outlet connector at the bottom of this tank, *and* in the end of the vent pipe (the pipe which curves over the top of the tank). Close both valves on all other radiators in the house, to keep the water in. [If the system has ever been balanced, count and record how many turns it takes to close each lockshield valve so that you can put them all back to the same position]. Then go to the removed radiator position, and open each valve in turn - catching the water which comes out in a container. When no more water comes out, you can disconnect/modify the pipework.
If your system has inhibitor in it (which it should!) save the water you drained out, and pour it back into the F&E tank before allowing water to flow into your neaw pipework/radiator. But let it stand for a while first, so that any black gunge collects at the bottom - and stop pouring just before you get to the black stuff.
HTH.
On Tue, 22 Nov 2005 14:54:48 -0000 someone who may be "Set Square" wrote this:-
In a sensible plumbing system, where both hot and cold (other than in the kitchen) taps are fed from a "cold header tank", it is easy to avoid running all the hot water to waste. Turn off the mains feed, or tie up the ball valve, then open a cold tap (other then the one in the kitchen). The water in the "cold header tank" will run away. After it has stopped, turn on the kitchen hot tap and a small amount of hot water will run to waste, but most of it will remain in the cylinder.
Such systems may not be fashionable amongst some, but they do have advantages.
What a great idoits guide you have done for me
Thanks
Paul
They are simple reliable and no moving parts. That's all. They are useless for showers, take up much needed space, use a lot of pipework, can accumulate debris and the occasional dead rodent in the cold water tank.
I recall a South African friend when we both went into the loft of his new house. There was water tank. He said "what's that?" I said "the cold water tank". He replied, "that's going out, this is no farm".
But the previous poster was takeing as given that there is stored hot water with its associated cold water header. He was simply discussing the pros and cons of feeding the *cold* taps either from the mains or from the header tank. I don't see the relevance of your remarks to that discussion.
Mr Square, you are very slow. Very slow.
*********
From: Doctor Drivel Subject: Re: room thermostat Date: Mon, 21 Nov 2005 08:45 Newsgroups: uk.d-i-y
You do not over engineer or make anything more complex than need be.
**********Try and make up your mind, dribble.
How good the shower is depends on the flow - not just pressure. Assuming you wish to get clean. And in any case the pressure depends on the head. Don't you know anything? Not everyone lives in a tiny flat as you appear to do.
Perhaps you'd be surprised to know that lids are available and should be used. It's also rather a good idea to prevent rodents entering the house.
A senile brainwave has overcome him and.....
He obviously can't figure this out. He goes on......
** snip senile tripe **** snip more senile tripe **
Sad? Yes, I know. Very sad.
I was hoping for an explanation of your complete about face. Fat chance.
[snip the rest of since it contains no useful comment. So nothing new there.]
I think we'll let others be the judge of that!
Sorry to butt in on this one but one thing the helpful poster didn' mention was how to bleed the system when the sink is replaced?? Chance are on this system water will not flow from the hot tap when it iaa s all connected back up because of airlocks. Ideally if you are fitting a monobloc tap then just hold your hand ove the spout and turn on hot and cold taps until the flow reaches back t the header tank.Don't hold on too long to prevent blowing th cylinder. There is maybe a safer way of doing this but i have never had an problem this way
-- freddyuk
Richard, intelligent people will see no about face. Do you see pink fairies too?
** snip Cranium senility **
So the lady's not for turning then?
On Wed, 23 Nov 2005 00:38:28 +0000 (GMT) someone who may be "Dave Plowman (News)" wrote this:-
Indeed. A 22mm connection from a shower boss on the cylinder and a
22mm connection from the cold tank (over two floors higher than the shower) gives rather more in the way of a satisfying shower than the relative dribble from a combination boiler. No need for the complication of a shower pump either.Must be used in fact. There are certainly no rodents (or birds) in any of the cold tanks that I keep an eye on for various members of the family.
Matt, no need to turn.
But you need a tall building and that over two floors is about 1 bar which is what a power shower pump may deliver. And this 22mm pipe will require a large cylinder which cost a lot to heat and a large water bills too. I have never come across dribbles from combi boilers, electric showers, yes, not combis. People want the pressure of a shower, not the flow so much.
Many leave them off and filth enters. Also any crud in the water accumulates in the tank. They should be drained periodically and cleaned out with special disinfectant.
You can't drink the water from a tank, you can drink all the water, hot and cold, from an instantly heated system: thermal store, heat bank, combi.
Using the hot water of mains pressure systems when filling kettles reduces expensive electricity consumption.
On Wed, 23 Nov 2005 12:13:59 -0000 someone who may be "Doctor Drivel" wrote this:-
Really.
As does filling the kettle from a hot water cylinder.
Well you can if you want, but foolish to do so.
Once again, "You can't drink the water from a tank". Or to be more specific, it is not drinking water and not recommended for drinking. Drink at your own risk
On Wed, 23 Nov 2005 15:49:11 -0000 someone who may be "Doctor Drivel" wrote this:-
Not in the least foolish, provided it is looked after as per the Water Byelaws.
There is also the more important question of incompetent companies putting undesirable chemicals in the water, like fluorine, but this affects one no matter how the plumbing in the house is arranged.
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