hot water draining

[brit]

is there any easy way to drain the water out of our brico bought hot water cylinder( just heats by electric) as it seems to get an air lock in it .

[sid]

Do you really want to drain it, or just get rid of the air lock? Perhaps further explanation of the original problem would help.

EDIT Although, perhaps I should have said that opening the safety tap on the bottom "groupe de securitée" and leaving a hot water tap open should enable you to drain the tank. some images here: http://tinyurl.com/qhroqjt  which should give you an idea of how that works.

doh ! ANOTHER EDIT ..... with the mains water turned off!!

[Anton Redman]

Disconnect both flexible pipes if you have installed check valves.

[brit]

we just wanted to drain it in case dont get back there until after the winter. ie to stop any burst pipes , have turned hot taps on but ended up blowing down washing machine pipe to break air lock and wondered if  there was an easier way for next time .

[sid]

Is there really an air lock? If you turn the mains off there is no longer any pressure in the system, so nothing will happen. It's not like the UK where you have a header tank which provides the pressure to the hot water system. Here it all works at mains pressure - turn off the mains and there's nothing to force the hot water out.

So, what you have to do is open a drain tap at the lowest part of the hot water system, usually the bottom of the hot water tank, and open another tap higher up, say in the bathroom, to allow air into the pipes and allowing the water to escape at the drain tap. This can be a  l-o-n-g  process!

The groupe sécuritée I mentioned previously has a drain on it. Not all tanks are fitted with flexible piping, as another poster mentioned, mine certainly isn't, it's copper pipe all the way. BUT if you have flexibles they could be convenient drain points too. Bear in mind that there will be 200 litres of water (or more) to get rid of, so a hosepipe connected to the drain is a good idea.

 

[sid]

Is there really an air lock? If you turn the mains off there is no longer any pressure in the system, so nothing will happen. It's not like the UK where you have a header tank which provides the pressure to the hot water system. Here it all works at mains pressure - turn off the mains and there's nothing to force the hot water out.

So, what you have to do is open a drain tap at the lowest part of the hot water system, usually the bottom of the hot water tank, and open another tap higher up, say in the bathroom, to allow air into the pipes and allowing the water to escape at the drain tap. This can be a  l-o-n-g  process!

The groupe sécuritée I mentioned previously has a drain on it. Not all tanks are fitted with flexible piping, as another poster mentioned, mine certainly isn't, it's copper pipe all the way. BUT if you have flexibles they could be convenient drain points too. Bear in mind that there will be 200 litres of water (or more) to get rid of, so a hosepipe connected to the drain is a good idea.

 

[SC]

[quote user="brit"]we just wanted to drain it in case dont get back there until after the winter. ie to stop any burst pipes , have turned hot taps on but ended up blowing down washing machine pipe to break air lock and wondered if  there was an easier way for next time .
[/quote]

Just to explain it further, when draining the cylinder, air goes in via the hot taps to replace the water that goes out through the security valve. Turn the supply valve on the groupe de sécurité off  90 degrees, turn the red test knob until it clicks and stays open, open all the hot taps. Water should flow out through the bottom of the security valve that ideally is  connected to a drain. The water flows quickly to start with and then spasmodically, accompanied by a lot of gurgling as air goes in. The process can take a couple of hours or more.

Blowing into the hot water pipe speeds up things but is a bit tedious....you must have a UK washing machine as I've never come across a French one with a hot feed.

In south Brittany we never drain our cylinders or pipes in the gites for the winter, they're all indoors and the cylinders themselves are very well insulated, but of course, we're on site to put on heating if necessary; it depends on your location....

Steve

[Chancer]

You are both correct but the slow process and the gurgling can be completely avoided by following the first piece of advice given, slacken/remove the hot water connection to the ballon, no need to blow into the hot water line which sounds grosse!

What happens when draining as described with the hot taps cracked open is that there are slugs of water in the line, often around what are called "dead bends" which shuttle backwards and forwards each time allowing a little air to pass making the gurgling noise, this does not occur if the hot connection to the ballon is opened and the cylinder will drain as fast as the water can fall out of the G.D.S..

hope this helps.

[sid]

Thanks for the further tips there and explanation, it's always useful to get more information like this. [8-|]

 

 

[Chancer]

A pleasure Sid [:)]

I should add that until quite recently I had been draining down like others and sometimes it took 24 hours, then I had my eureka moment.

The dead bend/slug of water thing is just my theory, thats what it acts and sounds like and it seems plausible, what I can say for sure is that a ballon will drain really fast if the hot pipe/flexible is released, it need only be a couple of turns as air is less dense and viscous than water.