Draining the system and fixing a leak

[stevie12345]

Hi last night i noticed a massive water mark in my kitchen and a slightly bulging ceiling. After a lot of hard work and the destruction of my nice bathroom floor tiles i've found the leak. The leak is in a hot water pipe which runs from the boiler to the hot water tank. What's the best way to fix it? Can i cut the pipe and fit a plastic connector hose or equivalent or do i need to solder a new bit of copper pipe?

In these cases do i need to drain the whole water system or is there a simpler way? If so how do i drain the system? Do i just turn the stopcock off and turn the taps on or can i isolate that pipe somehow?

Any help would be appreciated. Thanks

 

[seco services]

Personally i'd use a solder fitting if it's in a non accessable place.

Whats the leak from a bad joint, nail, pin hole from corrosion ?
Easier to locate a lower draincock and drain the system.
If it's an open vented system you'll need to isolation the ball valve in
the f/e tank, stop it filling while it's draining.

 

[bhm1712]

It would be wise to cut out the bad and solder in a new section of copper pipe with connectors. I wouldnt trust a plastic pipe with push fit or equivalent underneath a tiled floor - you might end up having to destroy the tiles again if the connectors fail.

Now its all ripped up and located, do it with copper.

You will need to drain the CH system not the domestic water supply. To do this depends on what system you have. Do you have 2 tanks in the loft, one small and one large? or do you have a sealed system with expansion vessel?

boiler type?

 

[bhm1712]

just beat me to it seco!

 

[seco services]

just beat me to it seco!

Your not on the ball today.

 

[stevie12345]

HI thanks for the replies. It's a gravity fed hot water system with two tanks in the loft. I presume the tanks are a header tank and an expansion tank?

How would i drain the heating system with these?

Thanks again

 

[bhm1712]

isolate mains incoming water supply at stop cock or tie up the ball cock in the small header tank ( this is the feed and expansion tank for the central heating, the large one is for the hot water cylinder and possibly cold water feed for bathroom cold tap and/or shower) either way is ok, but its easier just to isolate at the stop cock.

find a drain point which will normally be somewhere around the boilers vicinity or could be on the tail end of a radiator valve downstairs. Basically the lowest point in the system. Fit hose pipe to drain valve and open it and allow water to drain somewhere safe. To completely empty the system you will need to vent the rads and manually force any motorised valves open (with the slide handle on the side of them)

To refill, close the drain valve and close radiator vents. Turn water back on and allow header tank to refill. Once this has finished, vent each radiator to expel the air and allow the water in. Ensure motorised valves are still open.

Once this is done you will want to bleed the pump as well, this is done by opening the bleed screw in the centre of the pump and allowing the water to run out.

You may find that air is in the system for a day or 2 and will require regular bleeding. Replace the inhibitor liquid by either pouring it into the small tank or by buying one of those rapid fill cans which go straight into the radiator vent