No hot water, think cylinder is empty

cltt97

I had a minor leak in one of the pipes upstairs a while ago so this was fixed and I think the plumber might have turned off some valves including the one to the hot water cylinder.

I have a closed system and there is a pipe with a valve going into the bottom of the cylinder and the other end is going into the top of the boiler. The other pipe is going out at the top of the cylinder and is going up into the attic. I assume one of these two feeds water into the cylinder and needs to be turned, but which one? Any ideas? [There is one third valve that feeds water into the boiler, I know that one and that's somewhere else]

I'm quite sure it's one of the valves because I get a little bit of hot water every couple of days, so there is SOME water getting in, but not the normal amount, so don't think it's an airlock.

Any ideas?

Micky Dolenz

Are you getting any water out off cylinder or just that it isn't hot?

cltt97

No, I do get hot water, just only very little every two days or so and then it runs out. I'd say I can fill about half a sink and then it runs out. So it takes about two days or so to get that amount of hot water, that's why I think one of the valves is almost totally closed, so no water gets into the cylinder... would that make sense?

Micky Dolenz

Can you see two pipes that enter the cylinder in the side, one low one high, they run parallel and about 18' apart, when the heating is on these two pipes should be hot. the lower pipe may should have a valve on it. Open this up a bit.

cltt97

There are two pipes coming in at the left, both are hot, the lower one leads directly from the cylinder into the boiler and this one as a valve. The other one which is a bit higher branches off and one end more or less leads to the pump, the other to the expansion vessel. Then there is a pipe going into the bottom right, this goes straight into the attic and also has a valve and then there is on pipe going into the very top of the cylinder, but there is no valve anywhere.
My feeling would be, and it would in accordance with what you're saying, is that I should openthe valve of the bottom pipe that connects the boiler with the cylinder. The only other valve I could turn is the one going from the pipe that leads straight into the attic, but that would not make sense (to my limited plumbing mind)...

laois hibby

the 2 pipes going into the side of the cylinder are heating pipes and won't affect whats going to your sink.
the other 2 pipes. 1 at bottom is your cold feed into cylinder. that should be turned on
the second pipe coming out of the top if the hot water coming out of the cylinder to taps and also to your tank as an overflow

hope this helps

cltt97

So it's the pipe that comes out at the bottom that goes up to the attic then? That would look more like a cold feed than the one that goes from the cylinder into the boiler, these are the only two that have valves that would regulate anything going in our out of the cylinder....

Micky Dolenz

Just to be clear again, do you have water at your hot tap even if it's cold? and that you only get a little amount of hot water before it turns cold. Or you have hot water then it runs out so you have no water?

cltt97

I have hot water (about half a sink worth) and then it runs out and I have no water coming out of the hot tap (bathroom and kitchen). No problem with the cold water feed (and taps) at all.

laois hibby

is the valve to the bottom of your cylinder open? anticlockwise

Micky Dolenz

Ok, forget what I said earlier then . Forget about the pipes I talked about and look for the pipe that enters the very bottom of you cylinder will have a valve on it along the line. Make sure it is open fully.

cltt97

Which one? I have two pipes that go in at the bottom of the cylinder (one on the left side and there's another one going out about in the middle, the other one is at the bottom right). One goes direcftly into the (top of the) boiler, the other one goes up into the attic, both have the same type valve (round wheel). That has been my problem all along, that I don't know which one of these two feeds water into the cylinder....

laois hibby

the one that goes up into the attic.
that is your feed.
the one in the middle which goes to your boiler is part of the heating system. nothing to do with your tap supply

cltt97

Many thanks, I'll give that a go so. just out of interest, the one that goes to the heating system, what is the function of it? Would really like to understand this plumbing better! that valve is definitely turned off...

Micky Dolenz

cltt97 wrote: »

Many thanks, I'll give that a go so. just out of interest, the one that goes to the heating system, what is the function of it? Would really like to understand this plumbing better! that valve is definitely turned off...

It restricts flow of heating water to coil of cylinder. It encourages more heating water flow to rads.

If it is closed, the coil won't heat meaning no or very little hot water in taps, you would however get cold water coming out of hot tap.

cltt97

So should that be opened up then, too? and in effect, both valves of the pipes going into the bottom of the cylinder should be open?

sullzz

the valve on the pipe which goes from the bottom of the cylinder up to the attic should be open fully this is called "the cold feed to the cylinder" if this is closed you will get no water out of your hot taps as no water is getting into the cylinder .

the other valve on the other pipe at the bottom of the cylinder is called "the balancing valve" this should usually be open only about 1 or 1 and a half turns and should never be adjusted unless by a plumber , i usually remove the wheel head after fitting these balancing valves .

it sounds to me like your problem is an airlock , try as the other poster suggested and open the hot tap at your kitchen place your hand up tight to the spout and open the cold tap , keep your hand there for a couple of mins, this sometimes solves the problem.

if that does not fix it you could try this , if your confident enough, dont try it if your not too handy , close the cold feed to the cylinder and disconnect the nut at the bottom of the valve , place the open end of the valve into a basin or bucket and open it , let the water flow until its flowing strongly , close the valve and reconnect it back up , turn on the valve and you should have water again , this way of solving hot airlocks never fails .