Replace Washer or Ball Valve Unit on a Cold Water Tank

by **Havana08** » Fri Sep 12, 2008 8:05 pm

Hi All,
I have read all the great advice relating to the replacement of the above, however I am now confused and wish to know the easiest option for a person of medium skill and first time experience plus the tools I need pls.

2 weeks ago the pipes were banging loudly after I ran a bath and the noise would then subside but not disappear, today I got up to find the overflow pipe cascading. I opened the top of the tank & found that cold water was still entering in great quantities and the overflow spilling out equally. I lifted the ball valve to the (shut position?) but nothing happened. when I looked into the tank I could see a small white plastic plug type fitting sitting on the bottom of the tank. The tank is 25+years old and this is the only problem I've had with it. Have I read the symptoms correctly? easiest DIY option please. All good advice greatly received. Thank you very much. Havana08

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by **nitro23456** » Sat Sep 13, 2008 2:51 pm

correct. new valve required. £5 and 5 mins, turn off the water, partially drain the tank by turning on taps, change the inlet valve, spanner required.

by **plumbbob** » Sat Sep 13, 2008 7:52 pm

You will need more than one spanner. Mole grips or a Stilson will be required as the nuts holding the ball valve to the tank are quite large, and very probably bigger than any adjustable spanner you may have. The nuts are likely to be seized after 25 years so may be a little difficult to undo.

Before you buy the new ball valve, be aware there are two types. The difference being one has a straight arm (part one regs), and the other has an elbow in it (part two), so make sure you buy the right one.

by **Havana08** » Sun Sep 14, 2008 5:53 pm

Hi, Thank you both nitro23456 and plumbbob for your advice.

This question I would like go to plumbbob as you mentioned (Part Types) in your reply. Firstly I assure you that even though the replies were posted very early saturday, I did not receive anything by 3.00pm so I went to my local Plumbers store and told them the same as told to yourself.
I told him that it had a straight arm with brass nuts (he replied that these are now illegal) and I was sold part2 bent arm with plastic nuts. Thanks to you I now know about part 1&2 but I didn't before I purchased. I can always return it I suppose.
Anyway, I have not done anything yet and have looked on the screwfix site to find examples of the fittings I have, plus the tools you recommended.

Plumbbob would you please have a look & let me know which fitting I should be using.
screwfix.co. item code 90110 float valve is identical to the one currently in the tank BUT I was sold an item similar to code 11518. Thank you very much in advance. Havana08 :?:

by **nitro23456** » Wed Sep 17, 2008 8:46 pm

Feed and expansion cistern can use part 1 or part 2 ball valve.
Cold water must use part 2 valve to conform with water regs.

by **bobplum** » Thu Sep 18, 2008 6:22 pm

question for nitro
does part 2 valves only apply to new installations or does it also apply to retro fitting in older tanks as in this chaps case
many thanks
bob

by **nitro23456** » Fri Sep 19, 2008 9:58 am

as far as i'm aware it applies to all installations. I'm no expert, but it makes sense.

by **plumbbob** » Fri Sep 19, 2008 5:52 pm

The point of the Part 2 valve with the elbow is so the valve assembly should be higher up the tank wall when first fitted. This ensures if the tank were to overfill, the water level would guaranteed to reach the overflow before the valve became immersed. This removes the possibility of back syphoning in the event of supply failure.

You may be able to fit a part 2 where a part 1 was fitted before, and the resulting lowered water level may or may not be a problem, but even if you do, the new valve may not achieve it's desired effect due to the position of the overflow.

Unless you are willing to replace the whole tank, you may have no alternative but to replace the part 1 with the same. Generally, I keep both on the van for this purpose.

Sorry for the delay, but I have only just seen your reply. It's the downside of this site: the delay caused by posts having to be approved
before appearing.

by **Havana08** » Tue Sep 23, 2008 7:50 am

Dear Plumbob,

Thanks so much for all your advice. I replaced the valve with part 1 type this saturday and it works perfectly. I feel very proud of the job done.

Plumbob is so right ,the correct spanners are a must and the job was easy following the advice given. Part 2 didn't work as the tank I have has a lip on it so the raised water spout on the part 2 valve wouldn't fit under it.

Right advice, right tools & right parts. Job Done!!!!!!!

Thanks Again. Havana08

by **nitro23456** » Thu Sep 25, 2008 9:10 am

Glad you got it sorted, but unless you fitted a double check valve with it, you have broken water regs and the law.

The plumbers merchant offered the correct advice.

I'd have probably done the same thing mind!