Christmas Disaster!

[Graye]

Can anyone give me an opinion on what is going on with our plumbing please? We live in a very old cottage, we have no central heating - just a hot water tank with an immersion heater. This heats the water for the bathroom basin and kitchen sink. The shower heats its own water separately. At the moment we have reasonably poor water pressure and I'm not sure whether the guy in the downstairs cottage may have been adjusting the stopcock recently (it's a holiday let so he's hard to encounter). On the other hand it's never been brilliant.
A couple of weeks ago we had a plumber move the hot water tank so that we had more storage room. The header tank is not in the loft, which is inaccesible, it's high up in the airing cupboard. The hot water tank was directly below, now it's offset about three feet.
Everything worked reasonably well until yesterday, when the hot water in the basin reduced to a tiny trickle. We've checked and the ballcock arm is set very low, the header tank is only filling about half way. If we push it down to allow more water in then the hot water flow increases for a while.
Looking online I can see that the new position of the hot water tank is not ideal, as is the straight flow of pipe now linking it to the heater tank. But I don't understand why this has suddenly happened. Short of going to the expense of having the hot water tank moved back again I'm not sure of a solution. Or could it be an airlock or something similar?

 

[jonboy]

[QUOTE We've checked and the ballcock arm is set very low, the header tank is only filling about half way. If we push it down to allow more water in then the hot water flow increases for a while.

Depending on the type of ball valve fitted to your header tank, you may be able to adjust the float on the brass arm and/or bend the arm up to allow the tank to fill up more keeping the final fill level below the overflow. The extra head of pressure may help.

 

[WHPES]

Is it just the basin where the hot water is reduced to a trickle (if so the tap waher may be stuck)?

Could the offset pipe be airlocked?

You should have an independent water supply to the person in the flat below so nothing they do should affect you.

 

[Graye]

Thanks for those two replies. The arm on the ballcock IS bent down but just at the moment I can't get any leverage on it to bend it up again. The tank is in an awkward place so I have to reach in blind to do anything and I'm nervous of brealing the arm.

The downstairs flow is also slightly restricted so I'm not sure about the washer idea, although that's something I will check.

We've had the immersion heater off since this begain but had it on briefly this afternoon. It seems to be heating the water far hotter than normal and is now running up an overflow pipe to the cold tank. I assume the thermostat may have been damaged too? It's now switched off again.

Can anyone tell me how we release an airlock please? Thanks for your help on Xmas Day!

 

[Bernie2]

Usual way to release an air lock is to connect a piece of hose between the cold main and the hot tap on the sink unit. Open hot tap and then cold. The cold water should blow back up the hot water supply pipe into the hot water cylinder that you had moved, then water may go up either the vent or the cold supply into the storage tank, pushing out the air as it goes.

Hold the hose on for few minutes before taking off.

Problems can occur depending on what sort of taps you have fitted or whether you have none return valves fitted. But perhaps the age of the property means you haven't got any fitted. In that case you may have a loose jumper in a tap that will stop backflow. Its a case of taking the jumper temporarily out, while you blow back.

 

[Graye]

Thanks for that. The taps are in fact new on both the basin (two taps - a mixer tap wouldn't work upstairs) and the sink downstairs (a mixer tap which normally has an adequate hot water flow but never strong.)

We've done as you suggest and seem to have a much better flow than even before this all happened. Will this go back to a dribble or might we have fixed things? So, assuming the immersion heater hasn't gone wrong (we have just switched it on to check how hot the water gets today) and assuming we can bend that arm straight, might we be fixed?

Could someone also please confirm that moving the tank sideways slightly has not caused this problem and that it should work OK? The two pipes I thought were horizontal do in fact have a slight slope to them. And it IS six weeks since the move was made.

As a separate point, the cottage below and this one were, back in the 1920s, one house. They were built in the mid 1700s. I really do think we have one water supply. There are two stopcock covers in our "yard" and four cottages. I'm not sure which one is ours at the moment but assume it will be the one nearest our cottages. We now have a meter but previously we each paid a standard rate for water. The owner of the cottage below used to work "in drains" and I know he has previously had the single manhole cover up to mess around in it. So I wouldn't be surprised if he had fiddled with the stopcock. It's just a matter of finding him to see what, if anything, he has done to the water supply. I wonder if, when we had our water meter fitted, he did something to compensate for a changed flow?

By the way, this is a great forum and I thank you so much for your help.

 

[WHPES]

If your cold water supply has been restricted, you will notice that the WC cistern will be slower to fill and the CW taps will have less pressure.

The airlocked part may not be at the cylinder and tank or anyting to do with the modification but may be elsewhere in your system. When it was drained to move your tank, air will have got in.

Do you have a thermometer to check the hot water temperature? Hold it under the hot tap when the immersion heater has reached max temperature and run the tap until the temperature steadies. It should be around 65 degrees C. If it is any higher, the immersion may not be set correctly or the thermostat may be broken.

 

[Bernie2]

It probably will be okay, if all the air is gone. The only doubt is the water main. Usually the cold on the sink is directly connected to the water main, as an access to drinking water.

By turning this on, it should give some indication of what sort of pressure and flow you have on the mains water supply. It should usually fill a 4.5 litre bucket in about 30 seconds or so, if its a standard layout.

What we are trying to find out, is whether the cold water supply from outside is filling the storage tank as fast as your using the water or nearly so. If it isn't of course, the store tank may empty and start the problems all over again

If it doesn't, have a look at the outside stopcock and make sure they are fully open.

Sometimes, although it's not really a holiday time job, if you have a water meter fitted they can have filters in that block up. Then its best to get your water supplier to check it out.

As to the new taps, they have probably got fixed jumpers or ceramic discs with none return valves on the supply pipes.

That may mean if the hot has one fitted, that the cold main water will not clear the air so easily, as the none return valve will stop the water pushing the air out.

But if as you say it has improved, then it may not have a none return valve on.

At a guess I doubt moving a cylinder sideways would harm anything.

What is probably more likely is that air has got in the system. If its down the cylinder cold feed it can be difficult to move.

As you can imagine connecting the cold mains across the taps does work, but if the airlock in the cold feed is stubborn, indicated by poor flow. The water may come out the vent pipe rather than push through the resistance in the cylinder.

Sometimes you can clear it by blowing down the vent pipe or sticking a hose off the water main down the cylinder cold feed. But as you say, if access to the tank is restricted it may not be possible.

Another thought occurred to me. When the cylinder was moved, the vent pipe off the top of the cylinder that discharges over the store tank, is not dipping in the water of the store tank is it? Easily done.

That will stop it from venting air.

 

[tackleburger]

If the storage tank is not keeping up with the original demand it would have drawn air in. As long as the tank is above the cylinder and piped correctly e.g. no uphill rises. It should work. I think you have an airlock and you ball valve needs adusting the latter may be the cause.

 

[GreenArmy]

Where's the Christmas disaster?