Water Cistern Ballcock

[doctormann]

Hi

 

Another plumbing-related problem.I'm afraid.  Still haven't sourced an ITC pump.

 

Right, I have an 1100 litre stainless steel tank that feeds water to the pump that I mentioned in a previous post.  The tank is fed directly from the water main - no stop valve apart from the one on the actual water meter so I can't isolate this part of the system without cutting water to the whole property. Can be done but inconvenient.  The water feed into the tank is via a ballcock valve and I've noticed that lately the ball seems to be riding more deeply in the water as if considerable pressure is having to be exerted in order to stop the water flow.  Looks to me as if the sealing washer/diaphragm/whatever probably needs replacing.

 

I've done this job on toilet cisterns and it's trivial because there is no access problem in these cases.  The ball valve in the 1100 litre tank looks to be completely inaccessible so I'm wondering if I have to remove the valve completely to get at the seal.  Usual Thai-style blue pipe - everything glued together so it looks like a cutting job.  I'll install a stop valve if I have to take the valve right out.

 

Has anyone out there managed to replace the seal without completely removing the valve in a case like this?  Any advice or suggestions would be welcome.

 

DM 

 

[CharlieH]

There was an opening lid at the top of my s/s tank and easier to replace the entire arm/valve with new. Unscrew one, screw back the new.

[doctormann]

Just now, CharlieH said:

There was an opening lid at the top of my s/s tank and easier to replace the entire arm/valve with new. Unscrew one, screw back the new.

 

Mine has an opening lid as well.

 

So, are you saying that it's possible to remove the relevant part of the valve via the opening without needing to cut pipework and remove the whole valve?  I can't really see what's going on unless I partially drain the tank and I haven't done that yet.

 

[CharlieH]

Yes thats right, you can unscrew the whole assembly and screw the new one in.

 

Close water feed first.

[doctormann]

Just now, CharlieH said:

Yrs thsts right, you can unscrew the whole assembly and screw the new one in.

 

Close water feed first.

 

OK, thanks.  I guess that I'd better partially drain the tank and take a look.

 

Then, all I have to do is find the relevant part(s) - just hope it's easier than finding an ITC water pump!

 

[CharlieH]

Should be no problem its identical to a standard cistern unit.

 

It should be fitted above the water level,  the ball being the level.

Tip: smear vaseline or similisr over the inlet valve after fitting, it helps preserve it.

[bankruatsteve]

The ballcocks are commonly sold in two sizes:  3/4" and 1" so be sure you know the correct size for your tank.

 

Edited April 10, 2017 by bankruatsteve

[doctormann]

1 minute ago, bankruatsteve said:

The ballcocks are commonly sold in two sizes:  3/4" and 1" so be sure you know the correct size for your tank.

 

 

I'll take the old one to the shop, that way I can be sure that I get the right replacement.

[bankruatsteve]

1 minute ago, doctormann said:

 

I'll take the old one to the shop, that way I can be sure that I get the right replacement.

But, if you don't have a stop valve somewhere in front of that you will need to turn off at the meter while you go shopping, yah?

[doctormann]

1 minute ago, bankruatsteve said:

But, if you don't have a stop valve somewhere in front of that you will need to turn off at the meter while you go shopping, yah?

 

Absolutely.  A stop valve will get fitted but there isn't one at the moment.  Plumbing shop is only ten minutes away so no real problem - provided that they have the thing in stock.

[bankruatsteve]

1 minute ago, doctormann said:

 

Absolutely.  A stop valve will get fitted but there isn't one at the moment.  Plumbing shop is only ten minutes away so no real problem - provided that they have the thing in stock.

Also get some of the teflon tape, if you don't already have it.  You will want to clockwise wrap at least 5 turns and a few more at the top before screwing back in.  Don't over-tighten.  Cheers.

[Crossy]

13 minutes ago, bankruatsteve said:

Don't over-tighten.

 

... and pray the previous chap didn't ...

 

Tie a length of string to your stilsons (water pump pliers or whatever), so you can retrieve them from the bottom of the tank.

 

Another t-shirt I own.

 

[eyecatcher]

Ball cock.....(invented by a Mexican priest!!) what a great term and if you are old school you will know its simply about looking like a ball, and a cock was another name for a tap.

 

Apparently the p.c brigade Europe way now refers to this as a "float valve" or so my mum tells me from a recent plumbers visit.

 

I wonder how long before they try to re name the trusted "bog flapper valve"?

[eyecatcher]

1 hour ago, Crossy said:

 

... and pray the previous chap didn't ...

 

Tie a length of string to your stilsons (water pump pliers or whatever), so you can retrieve them from the bottom of the tank.

 

Another t-shirt I own.

 

are they still there?

 

Otherwise I bet there s a good painful retrievel tale

[Crossy]

2 minutes ago, eyecatcher said:

are they still there?

 

Otherwise I bet there s a good painful retrievel tale

 

Snake catching loops are not just for catching snakes

[doctormann]

1 hour ago, Crossy said:

 

... and pray the previous chap didn't ...

 

Tie a length of string to your stilsons (water pump pliers or whatever), so you can retrieve them from the bottom of the tank.

 

Another t-shirt I own.

 

 

Already thought of that  -  very good idea!

 

[grollies]

''I've noticed that lately the ball seems to be riding more deeply in the water as if considerable pressure is having to be exerted in order to stop the water flow.  Looks to me as if the sealing washer/diaphragm/whatever probably needs replacing.''

 

Nope. Sounds like the ball is half-full of water. It will unscrew from the arm, remove it, empty it and re-fit (with some PTFE tape on the arm thread).

[doctormann]

34 minutes ago, grollies said:

''I've noticed that lately the ball seems to be riding more deeply in the water as if considerable pressure is having to be exerted in order to stop the water flow.  Looks to me as if the sealing washer/diaphragm/whatever probably needs replacing.''

 

Nope. Sounds like the ball is half-full of water. It will unscrew from the arm, remove it, empty it and re-fit (with some PTFE tape on the arm thread).

 

Possible - worth a check anyway.

 

[leyali]

 
Possible - worth a check anyway.
 

I hade the same problem just few months ago, and it was really the white plastic ball was full of water.


Sent from my iPad using Thailand Forum - Thaivisa mobile app

[doctormann]

Update:  the ball is not half full of water so it looks as though the valve seal will have to be renewed.

 

What seems to be happening is that, initially, on topping up the cistern, the ball positions itself correctly - maybe 1/4 under water and the inlet flow stops, as it should.  Wait a while though and it seems that a very small amount of water is still getting past the valve.  Over several hours, the level in the cistern gradually increases and more of the ball gets submerged until it's about 2/3 under.  The situation then stabilises.  

 

I shall take out the valve at my convenience (no pun intended - this is not a toilet!)

 

[Crossy]

1 minute ago, doctormann said:

I shall take out the valve at my convenience (no pun intended - this is not a toilet!)

 

If it does actually stop the flow before the tank is brimming, it's a job for "tomorrow".

[doctormann]

2 minutes ago, Crossy said:

 

If it does actually stop the flow before the tank is brimming, it's a job for "tomorrow".

 

Tomorrow never comes though!

 

You are correct - no urgency as quite a way from overflowing as yet.

 

[doctormann]

 

I'm resurrecting this thread as I still have the problem with the cistern over-filling.

 

Initially, I was pretty sure that it was an issue with the ballcock not shutting off the supply completely but now I'm not so sure.  There is another possibility, which is that the check valve in the pump - Hitachi WT-P_GX2 - is faulty and is allowing water, under mains pressure, to flow in the reverse direction, through the pump and into the cistern via what is normally the outlet pipe.  I assume that the check valve, which is built into the pump, should not allow this to happen.

 

I've looked at the Hitachi manual, such as it is, and it mentions something about an accessory spring that may or may not be needed in the check valve.  I can't make head or tail of it though.  My cistern - 1100 litre - is ground-mounted and the outlet is at approx the same level as the pump inlet so I don't know if I need the spring or not.  I haven't opened anything up to see if it is in fact in there.

 

Is it normal to maybe need an additional check valve on the cistern outlet / pump inlet?  I can't remember if my old ITC pump had this or not as all the bits were taken away by the little man that fitted the new pump.

 

The installation is typical Thai-style so there is no isolation valve on the inlet to the ball valve.  Makes things not very straightforward when it comes to fault finding.  I can prevent mains water from pressurizing the system, while still being able to fill the cistern and pump from it.  That's the configuration that I have right now so I'm waiting to see what happens to the ballcock level.

 

Any thoughts?

 

[VocalNeal]

Or tie a magnet on a string after.....

[doctormann]

Problem is sorted now.  

It became apparent that it was just the valve so  had it replaced.