Adjusting the PRV to go to 4 bar..?

[rpm]

Seen 6bar static pressure reduce to 0.6bar dynamic pressure along with the sort of flow you would expect from 0.6bar.

 

[rpm]

Not the greatest pic, but hopefully gives you an idea of the boiler - the hot flow is only 2 l/m less than off the cold mains, I doubt it is the issue.

View attachment 36032

Not the greatest pic, but hopefully gives you an idea of the boiler - the hot flow is only 2 l/m less than off the cold mains, I doubt it is the issue.

View attachment 36032

Not the greatest pic, but hopefully gives you an idea of the boiler - the hot flow is only 2 l/m less than off the cold mains, I doubt it is the issue.

View attachment 36032

Those valves supposed to be closed guys?

 

[dblvkrb]

Those valves supposed to be closed guys?

So.. I could test increasing the static (PRV) pressure to see if the dynamic pressure improves the flow, have I understood this right?

I'll pass on whether the valves should be closed (I did not install the boiler) - but it is working as expected and the hot flow is similar to the cold mains flow.

 

[Aire]

Yes you can increase the pressure, as I said your boiler is rated at 5 bar, stick below that and you'll be fine.

And no those valves aren't supposed to be closed, but then the hot feed coming from the top of the heat store should also feed the boiler through a blending valve mixed with the cold main. Whoever installed the boiler hasn't finished it.

 

[Riley]

If that’s a heat store then what pressure is that safe up to??

 

[dblvkrb]

Yes you can increase the pressure, as I said your boiler is rated at 5 bar, stick below that and you'll be fine.

And no those valves aren't supposed to be closed, but then the hot feed coming from the top of the heat store should also feed the boiler through a blending valve mixed with the cold main. Whoever installed the boiler hasn't finished it.

Thanks - I will definitely check out the boiler setup with the installer, the blending valve should be somewhere. The boiler is rated to 5 bar, just worried about the taps being rated to 3, but I think I may have to test this anyway to see exactly how much the flow rate is effected.

 

[Riley]

Dear lord why risk leaks and damage swap out the prv also what is the cold inlet pipe size to the hot water Store.

 

[Riley]

My suspicion is it’s a piping issue exacerbated by the restriction of a prv

 

[Riley]

Seriously though test it in various places you’re plunging straight in with what isn’t the answer and will not be told

 

[Aire]

If that’s a heat store then what pressure is that safe up to??

It's rated upto 5 bar, the boiler, flue gas recovery and heat store all come together. The heat store is pressurised by the heating water not the mains, it has a coil going through it which comes off the flue gas and back into the cold feed to the boiler, at least it should do but as I said, it's not finished. And I just want to point out to you again that I don't disagree with anything your saying and op has gone the wrong way about reducing his flow rate but for the sake of adjusting the pressure and how long it will take it's worth a try.

 

[Riley]

But it’s not answering the issue it’s a bodge

 

[Riley]

So what feeds the store??? Surely it’s mains water?

 

[dblvkrb]

Seriously though test it in various places you’re plunging straight in with what isn’t the answer and will not be told

What would you test first? If it isn't the PRV what do you think the issue is? The pipes were tested and cleaned prior to installation.

 

[dblvkrb]

It's rated upto 5 bar, the boiler, flue gas recovery and heat store all come together. The heat store is pressurised by the heating water not the mains, it has a coil going through it which comes off the flue gas and back into the cold feed to the boiler, at least it should do but as I said, it's not finished. And I just want to point out to you again that I don't disagree with anything your saying and op has gone the wrong way about reducing his flow rate but for the sake of adjusting the pressure and how long it will take it's worth a try.

Just want to add that the picture uploaded was about a month ago and probably was mid installation, but I am definitely going to double check it (and take some more pics).

 

[Aire]

So what feeds the store??? Surely it’s mains water?

 

[Aire]

What would you test first? If it isn't the PRV what do you think the issue is? The pipes were tested and cleaned prior to installation.

Take a picture of the stop tap and pressure reducing valve.

 

[Aire]

To be honest, I know we're going off track here but the whole system seems pointless to me, why run cold mains through heat recovery, then through a heat store only to blend it down to 30°. Why not just have the heat recovery?

 

[Riley]

Sorry im with you it’s a set ok that makes more sense but my argument still remains. I’m not arguing with the logic of what you’re saying but that still looks like it’s piped in 22 under the boiler for cold and dhw and op has said it comes in in 15mm so obviously it upsized too which is going to further affect flow

 

[Aire]

Hard to tell, the shock arrestor under the boiler looks to me like it's piped on a 15mm supply.

 

[Riley]

Not the tidiest install is it 🙂