Vaillant UNISTOR unvented, tundish dribble

[Ted808]

Still think there

I just noticed on the photo's, the distance below the tundish to the first elbow is too short. If you open the PRV's it will overflow?

Yes it does, all over the two port valves.!!!

 

[Ted808]

Thats the understatement of 2019! I could not be any shorter. Its not unreasonable to assume other plumbing is just as poor / cheap so do not expect non return valves on taps.

True and custard almost wants me to put old valves back as they might not have been faulty.

 

[Last Plumber]

Thats the understatement of 2019! I could not be any shorter. Its not unreasonable to assume other plumbing is just as poor / cheap so do not expect non return valves on taps.

Far point and thanks for the award!
lol.

 

[Last Plumber]

True and custard almost wants me to put old valves back as they might not have been faulty.

I wouldn't worry, it is difficult to diagnose things following other peoples poor work as they do things that you would not do yourself, (I'm going for the second understatement of 2019).
When you work on something, you do expect it to have been installed commissioned and working correctly before you attend. It is not always obvious that some plant pot bodged it and scarpered. 'Tell tale signs' (as yorkshire pointed out) here, are things like the D2 discharge . Another is (possibly) that the balanced cold has been used at some point and then blanked off. That may well be innocent but under the circumstances I would rub my chin, frown and make an mmmmmmm sound!!!! Another is the white residue all over the tundish?
I cannot see what that is but I suspect from the photo that it has been wet for a while?
If you manage to solve this issue and leave it trouble free, no doubt you will gain a regular customer.
As an additional note which you can ignore if you like, i always install a pressure gauge in the side of those blocks where the black plug is, just so I can easily see what's going on. They are only cheap but it's another sale and it makes life easier.

 

[Welder]

I wouldn't worry, it is difficult to diagnose things following other peoples poor work as they do things that you would not do yourself, (I'm going for the second understatement of 2019).
When you work on something, you do expect it to have been installed commissioned and working correctly before you attend. It is not always obvious that some plant pot bodged it and scarpered. 'Tell tale signs' (as yorkshire pointed out) here, are things like the D2 discharge . Another is (possibly) that the balanced cold has been used at some point and then blanked off. That may well be innocent but under the circumstances I would rub my chin, frown and make an mmmmmmm sound!!!! Another is the white residue all over the tundish?
I cannot see what that is but I suspect from the photo that it has been wet for a while?
If you manage to solve this issue and leave it trouble free, no doubt you will gain a regular customer.
As an additional note which you can ignore if you like, i always install a pressure gauge in the side of those blocks where the black plug is, just so I can easily see what's going on. They are only cheap but it's another sale and it makes life easier.

And next best understatement of 2019 goes to?

 

[Ted808]

Another is the white residue all over the tundish?
YES been leaking for months, it's in an out house you see, and the termination of the warning pipe is in a dark little corner, turned into the wall, wall has turned green and neighbour complained, that's how they found out it was leaking!!
There is no cold water taken off the combination valve never was, only cold main coming into outhouse and hot going out...
Would it be unreasonable to put a check valve on the hot supplying the taps, to stop the reverse flow. I haven't been back but I suspect the bathrooms all tiled up to the eyes and no isolation valves for the mixer taps. I did ask about his mixer taps on the first visit, he said no problems...... will have to ring him today...

 

[Ted808]

UPDATE: Put a check valve on the hot supply from the cylinder and so far no news is good news. When I disconnected, there was definitely a good constant dribble coming down the hot- presumably from a mixer tap somewhere... they have a few.

 

[Tim S]

Bristan currently include nrv's on their mixer tap tails but the majority of other shower mixer/mixer tap manufacturers don't bother.

 

[Harvest Fields]

Bristan currently include nrv's on their mixer tap tails but the majority of other shower mixer/mixer tap manufacturers don't bother.

Not on all of their taps mate

 

[Ted808]

Well, I was feeling chuffed too soon, back to dribble in the tundish, separated out the two into buckets and the prv 6Bar was the culprit.
So, back to the drawing board...
Tried isolating the whole lot, two port valves shut, F+R to boiler off, incoming main-OFF. Yet after some time the , now added pressure gauge, crept up, then all of a sudden raced up and I could hear the hiss of water being used in the house...
Disconnected check valve and lo +behold the bluddy thing was letting by- So think I'll return with a double check. Has anyone has this happen? 3 Weeks for a check valve??

Of COURSE HE DOESN'T WANT TO PAY EXTRA