leaking overflow

[snatch]

the overflow from my header tank has started to leak. i've turned the mains intake down but that has affected my water pressure and everytime i turn it back up within a couple of hours the overflow starts again.

i'm guessing its something to do with the ballcock in the tank but what do i need to do to adjust it and stop this happening?

 

[Softus]

The first step is to get into the loft (strip first, in this heat), and see whether or not water is dripping from the ball valve when it should be shutting off.

If it is, then the solution is really simple - replace the ball valve. They can be repaired, if you reeelly want to, but they're only a few quid and it takes only a few minutes to change one. Tip - don't remove the whole assembly from the cistern, just undo the . Clearly you need to shut off the mains while your doing all this.

If there's no drip from the ball valve, then feel the temperature of the water. If it feels warm, then I would go looking for a shower valve that has mains-fed cold and tank-fed hot supplies. This imbalance has been known to cause cold water, at mains pressure, to force stored hot water from the cylinder up to the cold storage cistern. The solution is rather more complicated, because you need to balance the pressures to the shower valve.

The same thing can happen to a basin mixer; not that I've seen it happen, but others on the forum have reported it.

Hope that helps.

 

[Agile]

The correct water level is only about 100 mm and the ball valve arm should be bent to achieve this.

When the system water is hot then the ball becomes submerged as the water expands, thats normal.

You have to see where the ball switches off the supply. Many people just replace the valve without bend adjusting it due to their lack of experience.

Tony Glazier

 

[grrinc]

Header tank as in the small central heating supply tank, or as in the large cold water supply tank??

 

[Agile]

Little one!

But really! You should be following the leaking overflow back to see where its coming from!

Alternatively see which cistern has the water level up to the overflow connection level.

I thought plumbing was simple?

Tony

 

[ChrisR]

Many people just replace the valve without bend adjusting it due to their lack of experience.

You're using the wrong float valve then Tony, you shouldn't be bending anything. Balls on BS1212 part 2 valves adjust up and down the vertical(ish) end of the arm.
"Part 1"'s shouldn't be used there.

 

[Softus]

OK - got the wrong end of the stick at the beginning - apologies I caused any confusion.

The possible causes of the F&E overflowing are:

1. Faulty/worn ball valve (cheap to fix);
2. Faulty DHW cylinder coil (expensive to fix).

In your case snatch, because slowing or stopping off the mains has an effect, it's almost certainly the first one, so the advice from Agile and ChrisR covers that.

Regarding Part 1 & 2 float arms, often the mounting hole for the valve has been cut so high that even a Part 2 adjustable arm won't reach low enough, which is why the arms end up getting bent.

 

[Agile]

Perhaps in affluent and leafy Surrey the installers all use Part II valves on the systems they install for the City Bankers.

In the real world North of the Thames where the working people live all the valves I ever see are Part I.

In fact I can probably say that the only Part II valves I have ever seen in header tanks are those I have fitted myself!

Tony

 

[ChrisR]

Perhaps in affluent and leafy Surrey the installers all use Part II valves

Perhaps some would rather flaunt their professionalism by spending the extra 30p than crowing on a website

 

[Softus]

ollski made an excellent point on another topic, which was that you often don't need to change the entire valve - after isolating you can just undo the big union, on the inside the cistern, and replace that part of the valve.

This avoids (a) disturbing the water connection onto the valve, and having to replace the washer so that it doesn't leak, and (b) unnecessary work.

 

[Agile]

Whilst there may be good reasons to do that, I do not think that the IPHE would necessarily consider that as a professional way to do the job.

If I get a moment I will ask on their forum and see what their response would be to a complaint from a consumer.

Tony

 

[Softus]

Whilst there may be good reasons to do that, I do not think that the IPHE would necessarily consider that as a professional way to do the job.

Oh but it is the most professional way to do the job - it's quicker, therefore more customers can be served in one day, and the larger with the new fibre washer is by far the easiest to seal, with no risk of causing damage to the house should it happen to weep (but they never do).

If I get a moment I will ask on their forum and see what their response would be to a complaint from a consumer.

You might have the best intentions Agile, although I don't what those are, but fortunately none of my customers have the slightest interest in what the IPHE thinks - they're concerned merely with getting the job done at a fair price and not having any cause for me to come back again.

With one notable exception, all of the customers I've ever served consider, as I do, that the risk of changing the whole valve doesn't justify the reward.

Edited to correct a faulty quote mark

 

[grrinc]

If I could add...

I always replace the whole valve and replace the fibre washer with a few wraps of ptfe. I cant see changing just half of the valve saving me any real time that would allow me to serve more customers in one day. Although from a professional point of view, i would have no problems changing half a valve, I just cant see what real time savings can be made. Unless of course, changing float valves was all I did and a daily quota had to be met.

 

[Nige F]

Isee what I`ve been doing wrong all these years I used to get the valve out with stillsons........undo the capnut onto the tail.........clean off the old hemp .........remake it with a strand and smear of paste..........make a new grommet from hemp for the cistern wall......put it all back.........polish the float.........fill up and check the overflow......examine the cistern for rusting thru.........No wonder I`m a poor bugger with not a pot.....or vase to **** in

 

[ollski]

I suppose the main downside is that the valve will not be equally shiny throughout although a quick wipe of of brick acid should soon sort that. In all honesty you wouldn't replace the housing when you replace a dv diaphragm so why replace the valve connector on a tank....indeed with an asbestos cement tank it is the only way to do it.