2 port valves __________

[Loubanez]

Are 2 port valves necessary on the

flow of heating if a underfloor heating manifold is used such as this one in the picture? As far as i was aware the manifold acted as a valve.
Thanks

 

[chris watkins]

The manifold controls the temperature of the water & the rooms but what it can't normally do is provide an "interlock" with the boiler which is required by Part L of the Building Regulations.
Effectively what this means is that when the last power head on the manifold closes there must be a mechanism that turns the boiler off to stop it from wastefully cycling.

 

[chris watkins]

It also normally provides independent time control for the U/F against other heat emitters or areas which is also a requirement.

 

[Loubanez]

Ok i thought the actuators provided effective open close mechanisms for the zones, are you saying that the for the SL for the boiler should be wired in series via the 2 port valve?

 

[Loubanez]

Their is interlock terminals on the wiring centre for the manifold

 

[Jones82]

wouldn't a room stat wired into the underfloor pump and boiler act as an interlock?

 

[chris watkins]

Ok i thought the actuators provided effective open close mechanisms for the zones, are you saying that the for the SL for the boiler should be wired in series via the 2 port valve?

SWL through the end switch of the zone valve is the norm.
It is down to you to prove / provide that the "interlock" is in place if not.

 

[Loubanez]

Ok think I'm with you, bear with my I'll just a humble spark, so valve wired to far left interlock terminal and then switch wire off to boiler.

 

[Aire]

The manifold controls the temperature of the water & the rooms but what it can't normally do is provide an "interlock" with the boiler which is required by Part L of the Building Regulations.
Effectively what this means is that when the last power head on the manifold closes there must be a mechanism that turns the

How can that manifold not provide interlock? Interlock is easily provided by the room thermostats that will be used for each zone. Zone valves are used to separate systems when required. If you have a fully pumped/system boiler then yes a zone valve is required to separate the heating and hot water circuits but if you don't require your ufh to be separated from your radiator circuit then a zone valve isn't required.

 

[Loubanez]

There is no radiators purely underfloor heating 6 zone each with a programmable stat

 

[Aire]

There is no radiators purely underfloor heating 6 zone each with a programmable stat

Is it a combi or fully pumped system?

 

[Loubanez]

Unvented cylinder with electric boiler

 

[Aire]

Yes you will require a zone valve to separate the heating and hot water circuits

 

[Loubanez]

I already have a valve on the hot water for the cylinder but do I need another one for the heating? Or will the manifold suffice?

 

[ShaunCorbs]

Best to else you could get warming of the ufh when the hot water is on