Residential Boiler Piping Question

[Hockey Nut]

Just after the back-flow preventer, there is a piping loop with a pressure reducing regulator that connects directly to the pressure tank.

Should both shut off valves be open? The top shut off valve (yellow arrow) is closed and I haven't been able to find any info on why it should be open or closed.

Any insight would be greatly appreciated.

Thanks!

 

[WorthFlorida]

It is a bypass valve for the PRR. Not sure why it is there. Always keep it closed.

 

[Sponsor]

 

[Hockey Nut]

Thanks, appreciate the input. It's a little confusing (I'm no plumber ) the installation manual (Prestige Solo 110) does not show this loop installation, but newer versions of this boiler model do... Maybe there was a retrofit done in the past to the piping, I'll have to look into that.

Valve closed!

Pics attached for reference.



* I see the open valve position in this diagram... that's where it all started

 

[BillTheEngineer]

It's probably there just to help purge the system of air the system of air. But it's not really needed, and potentially a risk to over pressurise the system and cause the safety relief to open.