Vaillant ecotec plus 937 - Storage tank pressure relief valve

[aido]

We had a Vaillant ecotec installed 5 years ago and its been serviced a couple of times since. We never had an issue with it, until about 2 months ago I noticed water leaking from it, which I traced back to what I think is the pressure relief value of the internal storage tanks. Its a white pipe on the left hand side when looking from the front. See photo below the pipe with the blue knob. As you can see its not terminating anywhere.

My questions are, any ideas why this is now releasing water , approx. 50ml a day?
Should it terminate somewhere or remain as it is? As Ive said the original installer and 2 other engineers who serviced the boiler never commented up this so I presume its ok.

Cheers
Adrian

edit: added missing image

 

[ScottishGasMan]

It's a high pressure discharge valve, which should be routed to terminate in a safe place (which is not leaking in your house)

Either the pressure in the mains feeding the house has increased or more likely the mini expansion vessel that takes the pressure increase of the storage tank heating is faulty, probably not been checked and recharged during service if they haven't bothered to note that the valves not discharging correctly.

Ps, few assumptions made, your picture hasn't shown up

 

[aido]

Hi

Thanks for taking the time to reply. I've attached the image again above. Does this look correct to you and back up your assumptions? Should this be terminated?

Cheers
Adrian

 

[Biggles..]

Highly likely the vessel hidden under the access panel on the store has never been checked, and will need a quick re charge.

 

[aido]

Thanks for the replies. So I presume I need to get a plumber in to 1) recharge the storage tanks and 2) terminate the pipe from the pressure relief valve in a safe place. Which begs the question, once a pipe has been added to the relief valve and terminated somewhere, how in future would you know if there is an issue as you would not be aware of water being expelled by the pressure discharge valve. Also curious to know why it was installed this way and not picked up on by 3 other plumbers! Thanks again for any help.

 

[wannocks]

It's the (domestic) expansion vessel that will need charging, not the storage tanks. The discharge line should be piped to outside in a visible location. You may wish to put a safety cage over the end.
It's that way because your installer missed it or didn't care.
It hasn't been mentioned because your service guy didn't know about it or didn't care.

It is worthwhile to get it done as this valve could discharge a large volume of hot water under fault conditions.