Is this allowed??

[brian30]

Hi

I've just had a heating system installed. Vaillant 831. Happy with the work. System was properly flushed and instaler went through controls,operation etc.

However, looking at it from outside i have noticed that the pipe from the pressure valve comes out of the same hole as the flue. I know it took ages to core because my house is made of thick solid stone.

Spoke to a friend who is a plumber. He said that its not allowed but couldnt explain why not.

 

[DP]

PRV pipe cannot exit from the flue hole. The pipe from the PRV must not have any water in it that can freeze or block up the pressure relief valve. If it did and system pressure started to build up, you could have an uncontroled device on the wall waiting to blow up.

 

[brian30]

What is this classed as so i can call the installer back

 

[undercover]

i would say its 'At Risk' (AR).

call the installer back to remedy

 

[sooey]

The blowoff pipe should have a constant fall, so how did he get it out the flue hole? Can you show us a pic or two, just for a laugh.

 

[undercover]

at risk and warning notice

 

[gas4you]

The blowoff pipe should have a constant fall, so how did he get it out the flue hole? Can you show us a pic or two, just for a laugh.

My thoughts exactly, flue is about 900mm above prv pipe

 

[namsag]

From what i hear corgi are now thinking of allowing this.

 

[weareleeds]

Not at risk it is n.t.c.s.

 

[mehran]

if every thing else is all right then i would forgive him this.

 

[sooey]

From what i hear corgi are now thinking of allowing this.

Sounds odd, what wil the manfacturers say about that.

 

[namsag]

Most manufacturers added it to there instructions that it must fall continously a few years ago , after people saying show me where it says i can`t do that.. Have seen quite a few fitted like this
As for freezing it should not do this due heat from the flue,and as they blow at 3 bar this should move any standing water already in there are the theories. Was told about possible change a few months ago. Will check with my corgi mate if i see him over weekend.

 

[megawatt]

Whilst I wouldn't have a problem using the same hole as the flue for convenience most manufacturers specify that the PRV discharge should run down away from the boiler and this cannot be achieved using the flue hole.

Given the time it takes to drill a hole for a 15mm PRV outlet, bit of a no-brainer really

 

[Onetap]

As for freezing it should not do this due heat from the flue,and as they blow at 3 bar this should move any standing water already in there are the theories. Was told about possible change a few months ago. Will check with my corgi mate if i see him over weekend.

They should blow at 3 bar but, if they don't reseat properly, the PRV will drip causing a gradual accumulation of water in the vent pipe. This can freeze and can affect the operating pressure of the PRV.

 

[sambotc]

Spoken to vaillant about this on the phone and they said they would allow this providing the there is a drain off which allows any water trapped in there to be removed.

This was about 9 months ago so may have changed!

Apparently some manufacturers recomend terminating into a 10 gallon tank internally instead of taking the PRV pipe up!!!!

Sam