150L Ultrasteel Unvented Cylinder - Water dripping through

[jon2t]

I have a 9 year old Ultrasteel unvented cylinder 150L that has recently had a problem with dripping water through the tundish.

I called a qualified unvented cylinder engineer who replaced the hot water temperature/pressure valve, then the cold water pressure valve & now the expansion vessel.

Unfortunately it is still dripping (water is semi cold) and is baffling the engineer.

Would anyone have any advice for me or him to solve this problem?

I understand its process of elimination & past experiences but there must be a solution.

Many thanks

Jon

 

[Whn1]

Have you tried he pressure reducing valve?

 

[Whn1]

Is the expansion vessel correctly sized?

 

[jon2t]

Thanks for the quick reply guys,

He hasn't replaced the pressure reducing valve yet but said if it was the PRV it would be more of a flow than a drip.

The expansion vessel is a 12L that is recommended by Ultrasteel documents..!!

 

[chris watkins]

Hi Jon
Why did the engineer replace both the safety valves ? was it not possible to loosen the outlet connection from each one to find out which one was causing the problem ??
Also was the expansion vessel full of water or would not hold a charge ??
Will they not come back & fix the problem for you, for nothing, as they presumable have charged for all the others work.
It is not a go at you Jon, just another case that highlights the difference between qualified & experienced, we are all gaining experience as we go, just don't thing you should paying someone who can't fix what you have employed them to, due to their lack of it.

If all the things replaced are not the problem, then there must be an increase in the system pressure from somewhere which is causing the valve to lift, it could be the PRV or an external cross connection but a pressure gauge connected to the system would show the system pressure to confirm either way, I would get an experienced engineer to have a look.
What area are you ?

 

[Whn1]

As chris said there are easy ways to test the components individually, you don't need to change everyone.

 

[jon2t]

Hi Chris,

The guy said the T&P valve is usually the common problem so fitted & got charged £150. It looked fine with no evident signs of scale.

He then came back & changed the Pressure valve which did have scale & he hope that would solve the fault.

He then came back & changed the expansion vessel & pumped it to 3 bar, the old vessel was full of water which he said that the diaphragm had probably split.

It's still dripping after all 3 parts.

I haven't paid for any other parts or labour yet..!!!

I will dispute any labour costs although i can understand to a point the charge for the new parts as long as the price is not inflated.


I agree with you on the qualified & experienced quote....!!!

As a non-qualified plumber you have to trust the company you contact, that’s why i went to a reputable local established firm.

They have been ok & do the work on a Sat where they can but i would like it sorted


Cheers


I'm in Essex

 

[Whn1]

I think he would have changed the pressure reducing valve as it should be combined with the relief valve.

 

[Whn1]

Back flow from an unbalanced kitchen sink mixer? Just throwing it out there.

 

[chris watkins]

Was the water dripping through Tun dish at the time of his first visit, before he said it was the T&P ? & like wise the second visit ? ("probably split" one push on the schrader valve would tell if it was or wasn't) It is easy to be critical from a far but sometimes when it is basic stuff, I despair, poor or little training I guess.
If you get stuck PM me.

 

[jon2t]

The water dripping was the original fault,

I had a call from the shop below saying there was water dripping from above.

I located it to the area of the unvented cylinder & found that the drip that was coming from the tundish was not dripping from top to bottom but dripping to the side of the tundish & dripping on top of the vessel then onto the floor (just unlucky i guess).

I cleaned the scale in the tundish that made it drip to the side but wanted to stop the drip for good even though not causing a problem to the shop below.

Every time he comes the drip slows down then 30 mins later the same constant drip.

cheers

 

[jon2t]

Hi,

Thanks Chris & whn1 for help on this, ive attached a video clip on you tube (yes sad i know) but thought visual is better than words sometimes.

Not done this before so please let me know if you can see video clip..??

I think you have to copy & paste to the top search bar & not in the google search (i have no idea)...!!!!

youtube.com/watch?v=fnURoNfxYSY&feature=youtu.be

Cheers

 

[Si H]

How water temp to high?? Just a thought!! Faulty cylinder stat?

 

[Whn1]

Temp of the Water through the tundish isn't hot enough for external control probs.

 

[Si H]

Temp of the Water through the tundish isn't hot enough for external control probs.

Thx Whn1 missed that bit on original post!

 

[lame plumber]

if he changed prv and tprv before the expn vssl problem noticed !!! then they could well have failed as they now have dirt in seals. check which one is leaking first and take it from there.

 

[Megaflo-Experts]

Does it drip when the hot water is switched off at the programmer (i.e. water not being heated up)?

Also, if you open a hot tap and leave it running, again does it continue to drip?

Do you know what your incoming water pressure is?

 

[payney1974]

Isnt red for non potable water?

 

[payney1974]

I would say its a unbalanced mixer in the house somewhere or the prv, test the standing pressure at a hot tap if possible?

 

[Mike Jackson]

Isnt red for non potable water?

Yes it is. The vessel for this should be blue or white.

 

[payney1974]

Yes it is. The vessel for this should be blue or white
A qualified plumber wouldnt put a red expansion vessel on DHW would they???? Am I missing something here?

 

[Megaflo-Experts]

The expansion vessel would normally come with the cylinder, so this one may have been replaced at a later date by someone unqualified!

 

[chris watkins]

Good idea with the video Jon, I ask for photos but thats much better. (some of those Hollywood directors better watch out, LOL)
The heating (red) expansion vessel says it all, this guy does not know what he is doing. As others have stated the potable vessels can be lots of different colours but NOT red which is only for use on heating systems (they are a lot cheaper & will not last long).
The grey plastic plug with the cross in the centre which is just below the pressure reducing valve is a gauge port a cheap pressure gauge can be fitted which will tell an engineer quickly what the system pressure is running at.
Do you ever notice a drain smell coming from the cylinder cupboard ??
Only ask because from what I can see, there is no trap fitted (not allowed) & the safety valve discharge waste is connected to 32mm solvent weld plastic waste (not allowed) it then tees into another waste from other appliances (not allowed). All of these are breeches of the Building Reg AD Part G & should be corrected sorry to be the bearer of bad news but then you probably new all that anyway cos the last engineer explained it all ???

Please ask to see the un-vent card or certificate before you let them loose in your home, these things can be dangerous if not installed & maintained correctly !

 

[lbp plg & htg]

I for one cant see clip but that dont mean owt! Is it a direct or indirect cylinder?

 

[lbp plg & htg]

Now i do, vessel is wrong type as previously stated and the orientation isnt the best. That said then others advice needs to be done ie undo the nuts and see which valve is passing (think you siad water lukewarm which should point to the expansion relief valve but a gauge needs attaching the the prv to see what pressure is passing through it first and if 3bar as its set too then exp valve it probably is.