what is it?

[jimlad]

Hi,

What is it? and is it necessary, it looks to me like stuff is sometimes flowing back up it, and it's after the u-bend so that lovely drain smell is prevalent

Thanks
James

 

[just pumps]

With the adjustable control knob it looks like a pressure relief valve, do you have high water pressure at the taps? And really don`t like the way the back hose joins the white plastic pipe lower down, is it just pushed in?

 

[jimlad]

This water line is feeding into a boiler to heat hot water for the tap, my guess is it's not any more high pressure than usual here in the netherlands, the plack pipe is pushed onto a nipple to feed into the down pipe.

 

[Madrab]

Pressure Relief Valve outlet on the cold water to the Instantaneous HW heater, it's a safety device. It's not very clear but looks like that grey cup is a tundish, can you see into that?
Wouldn't normally have a flexi pipe in the feed to the heater though, nor the D2 outlet after the tundish

 

[ianmcd]

It is a PRV from a single point Hot water heater and has been fitted wrong

 

[dilalio]

Discharge hose needs to be formed into a loop or a P to create a trap, at the very least.

 

[jimlad]

can you see into that?

 

[jimlad]

So there is a dishwasher outpipe linked in higher up, it it likely that water could be coming back up this black discharge pipe?

 

[Madrab]

Yes, very likely. As everyone has mentioned @jimlad that needs fitted correctly. Not sure how they do it in Holland but over here that just wouldn't be right.

Any blockages or restrictions and it will all pour out of that tundish. You will be getting smells from it too. It's a safety device and needs to be done properly.

 

[oilboffin]

It's no wonder their always in danger of flooding in holland.Bob

 

[dilalio]

Looks like a stored hot water heater, so what handles the expansion?

 

[Madrab]

so what handles the expansion

The flexi pipes

depends on the size of the unit, some of them can use the cold water supply pipe as long as there's a certain length back to a branch/check or isolation valve, which certainly wouldn't be the case with that install by the looks of it.

 

[jimlad]

It's no wonder their always in danger of flooding in holland.Bob

I might come back and remind you during the next UK flood where they call in the Dutch pumps.. again!

 

[jimlad]

thanks for everyone's input, you've been most helpful

 

[dilalio]

The flexi pipes

depends on the size of the unit, some of them can use the cold water supply pipe as long as there's a certain length back to a branch/check or isolation valve, which certainly wouldn't be the case with that install by the looks of it.

I know mate... I have one in my workshop and I used the cold supply for that purpose, by extending it the required distance from the unit to the stopcock/isolator.

But! I can't see any allowance for this in the photos above... Looks more like the PRV is being used to discharge the excess pressure