Feed & Expansion tank in open vent CH system - pipe rout

[PeedOftec]

..
I have an open vent CH system and want to know if the following is possible.

If you imagine the rads connected to a boiler in a central heating circuit round the house. As it is open vented there is a small header tank in the loft. There are three pipes entering this tank namely 1) the cold feed TO the tank from the mains cold water, 2) the vent from the radiator circuit and 3) the feed FROM the water in the tank to the radiator circuit.

Question... The vent pipe rises up from the highest point in the radiator circut and loops up over into the top of the small expansion tank.
Is there any reason why the cold water feed FROM the F&E tank cannot be linked into the vent pipe just under the said tank?
.
.

 

[thefloosyonthebeach]

No, but it can cause problems when your re-filling a 'combined' open vent system.

Flooze

 

[PeedOftec]

.
.
Ah yes, I can see that if the system was empty and turning the water back on the venting air would be battling to get out whilst the filling water was batting to get in down the same pipe. Unless there was an air bleed elsewhere that could be opened..... So it should work really....

Are there any regulations in the UK with regards vent pipes and feed pipes?
.
.

 

[PeedOftec]

.
.
Can't spel - the word is ROUTE not rout.. Dooh!
And it looks like I cannot edit the topic title double dooh!
.
.