expansion pipe on a open vented system

[oldplumber john]

Can you please tell me the possible problems caused by the vent pipe dipping into the F&E tank below the waterline.

 

[ShaunCorbs]

only one thread plz mate

http://www.ukplumbersforums.co.uk/central-heating-forum/91067-expansion-pipe-open-vented-system.html

 

[joni os]

Air lock on bend creating venting and filling problems, if pump on high point of system trapped air could cause noisy pump and early failure.

 

[oldplumber john]

have 12 rads on the system , 3 not working properly so I repiped the cold feed and vent too close couple 150mm behind the pump that is fitted to the primary flow pipe then into a threeport valve , when I fired up the system the vent and the coldfeed got hot ,I was wondering if the dipped vent into the F&E might have caused this heat up ? . it's an old system and i'm wondering now if there might be a sludge block to these rads , the flow to these rads get's hot so far but the return is cold , the pipework is all hidden in stud work and rises high but now iv'e resited the pipework it should push any air do you not think ?

 

[ShaunCorbs]

have 12 rads on the system , 3 not working properly so I repiped the cold feed and vent too close couple 150mm behind the pump that is fitted to the primary flow pipe then into a threeport valve , when I fired up the system the vent and the coldfeed got hot ,I was wondering if the dipped vent into the F&E might have caused this heat up ? . it's an old system and i'm wondering now if there might be a sludge block to these rads , the flow to these rads get's hot so far but the return is cold , the pipework is all hidden in stud work and rises high but now iv'e resited the pipework it should push any air do you not think ?

pipes to rads in 10mm also there should be free space between the vent and water line

 

[joni os]

Keep the vent above the water and test with a pump you know is working correctly.

 

[GQuigley67]

Make sure the pump is the right way around also, pump pumping the wrong way can cause the cold feed and tank to get hot.

 

[Millsy 82]

You can get gravity circulation up through the vent as in effect you have created a circuit for it to go round.

 

[oldplumber john]

Thank you all for your advice it's been of great use to me and has stirred the old grey memory bank

 

[Simon 45]

Hi
Is it possible the radiators may need be re balanced, someone may haved adjusted the valves without your knowledge.