Whats the valve for??

[kevfisher]

Hi there,
I was wondering if you could help....
I have a swiftflow 80 boiler and on the pipes that exit the unit there is a heating flow out and a return flow in for the heating. Once these pipes come away from the boiler they are later linked together with copper pipe and a stop cock type valve.
Does any one know if this valve should be open or closed
and
what the valve is for.
I recentley put a hole in one of the pipes and drained the system and in a moment of panic turned and switched everything off I could find and can't remember if the valve was off, half on or on fully

Thanks in advance

 

[Bahco]

It is a system bypass and should be set by a plumber to allow an open path back to the boiler in the case of all trvs shutting down.

It should be a little open always.
Perhaps one of the pros can tell you how to set it correctly.

 

[Softus]

Suck it and see - with the rest of the system running normally the bypass should be closed enough keep the correct temperature difference bewteen flow and return, and with all TRVs shut down it should be open enough to prevent the boiler overheating.

 

[Agile]

TRvs ? Who said anything about TRVs?

Had they even invented them when the swiftflow was fitted?

Tony

 

[Bahco]

Maybe the plumber anticipated the invention of Trvs when he fitted the system.

But seriously......why would a bypass be needed if there was always a open circuit i.e no trvs fitted?

 

[Softus]

TRvs ? Who said anything about TRVs?

Had they even invented them when the swiftflow was fitted?

Tony

Just being thorough and covering all bases Tony.

 

[Softus]

Maybe the plumber anticipated the invention of Trvs when he fitted the system.

But seriously......why would a bypass be needed if there was always a open circuit i.e no trvs fitted?

Because there could be a MZV instead of or as well as TRVs.