Tribune HE pressure relief valve

[King Ossy]

The pressure relief valve on my Tribune HE tank was releasing copious amounts of water onto my outside path, I have renewed the valve. Initially the valve worked ok with no water being released, but now after some 6 weeks the new valve is doing the same, there is a constant flow from the outlet onto my path. The valve that is passing water is the large valve on the side of the tank, the other 2 valves are not passing.

Does anyone have an answer to this problem, could the new valve be faulty? Or, is there a fault elsewhere in the system?

The system is 3 years old in a new build house.

 

[Puddle]

Well the pressure release valve is a safety fitting,installed to protect the unit,pipework and you,the valve is a temperature and pressure release valve and if operated ,it will of done so for a reason other than a fault in its self,so could be cylinder over heating,mains pressure to high,expansion vessel re-priming ect
If maintained the right hands,by a qualified person,these are safe units,if messed about with by others can cause damage and injury,would suggest you get someone in who knows the system and unit to repair and adjust safely

imho

 

[unguided1]

exactly as puddle has said, also unvented cylinders are supposed to have a 12 month annual inspection.
If the TPRV is letting by then there is a fault do not just change it for another one get a proffesional in to find the fault Unvented cylinders make extremley good bombs just look on you tube under mythbuster unvented cylinder!!!!!!!!!!!!

 

[casaco]

Hi, I am working on another cylider with the same problem, check the charge in the expansion vessel, should be 3 bar, see if you can feel how heavy it is becuse it may be full of water and there is a risk the weight will cause it to fall off the wall and maybe break the toilet like the one I'm repairing. You can no longer but the PRV seperately, you have to by the pressure reducing valve assembly which now incorporates the PRV. You might be able to salvage the old PRV if you clean it with a descaler while holding it open. You have to have an unvented cylinder ticket to work on these as if they go wrong they can be very dangerous.

 

[BLOD]

Hopefully the OP has had someone who knows what they're doing to sort this by now.
The only thing I'd suggest soaking in descaler is the twit who suggested it ! It's a safety device ffs.

 

[PlumbBobBob]

The only thing I'd suggest soaking in descaler is the twit who suggested it ! It's a safety device ffs.

totally agree BLOD people who follow this advice need shooting. with the superheated steam that will result.

 

[casaco]

OK, according to the Tribune service instructions if the PRV is passing you are supposed to remove it and check the seat for damage, if there is any evidence of damage to the seat then you are supposed to replace the PRV, but a damaged seat does not make the valve dangerous it only causes a nuisance by passing water. Assuming the seat is undamaged and is only being held open by a deposit of calcium or grain of sand, how does removing the deposit then make the PRV dangerous? As long as the valve re-seats after cleaning there shouldn't be a problem, sometimes just holding the valve open for a few seconds will clear the cause of the problem. I know this works safely, because I have cleaned several PRV's on boilers over the years without any problems what so ever. Also bearing in mind the PRV is now part of a unit that costs over £70 +vat + fitting, an attempt at re-seating the valve seems worth while to me, especially as the system is only 3 years old. I still suspect that the expansion vessel has lost its charge.

 

[BLOD]

Sorry casaco, but I stand by what I said and do not think people should be advised to "salvage" safety devices on an open forum.

 

[unguided1]

I agree with BLOD on this one

 

[SimonG]

When it comes to safety it should always be replace rather than repair.

 

[casaco]

Where's the danger, the expansion vessel has probably lost it's charge, the PRV is doing it's job, they only fail to safe not to danger, if the spring breaks you lose pressure, if they don't seat you lose pressure, the only thing that can hold them closed would be if they froze up or deliberate sabotage. Still can't see any danger in attempting to re-seat the PRV if the seat is undamaged, bearing in mind the chap said it was a new one anyway.

 

[unguided1]

if the chap said it was a new one any way, first of all who replaced it secondly if it is a replacement and the expansion vessel is ok there must some other fault on the system, why didnt the plumber who worked on it originally find the fault and why has he got another plumber in when the origanal plumber should be putting his work right??

 

[casaco]

Maybe the original plumber died or retired or just plain moved away, who knows, and the chap didn't say whether he had had his expansion vessel checked or not. To check if the PRV was faulty we would re-pressurise the EV and tee in a pressure gauge at the same time after inspecting and cleaning the PRV, (not the TPRV), if the PRV starts passing below 6 bar then replace it job done, if the system pressure exceeds 6 bar then yes you have a problem that needs fixing, but you can't tell just by looking, at what pressure the PRV starts to pass.
They no longer supply the PRV on its own you have to buy the pressure reducing valve as well in a combined unit and quite often have to mod the pipework. I've not had any complaints and have more work on than we can cope with so I must be doing something right.