Hi
I am just an old amateur realising that "a little knowledge can be a dangerous thing".
Could someone tell me whether there is any value in adding an open vent pipe to the cold feed on an open vented DHW fully pumped system? 30 years old system. Been having a problem with air in the system, noisy pump swishing etc ( 1 yr old Grundfos 15/50 set at speed 1) and F+E tank overflowing on system start up.
System Boiler26kw and pump ( on return) downstairs with 2 zone valves on the flow serving 7rads and 11 rads respectively ( single storey bungalow) Water tank + expansion tank in loft space.
Bathroom rad downstairs appears to be connected on its flow with an auto air vent in the loft which appears to act as bleeder for the whole system. Just changed this bleed device to a float chamber type and it has helped somewhat re air. But still the pump is a bit noisy off and on. Air or something seems to be moving round the system. Rad in kitchen only partly heated ( side to side - not top to bottom) now that seems to have moved to next new rad - same thing and less hot than other rads.
Discovered minimal distance - a few mm, between water level in the expansion tank and cold feed entry so bent the arm of the ball cock assmbly and now 25mm. Have just added - 2 hrs ago, X400 for a few weeks cos there is sludge and black M in the system.
At hot, very little distance from water level and overflow in the expansion tank.
//media.diynot.com/185000_184445_43617_52511225_thumb.jpg
//media.diynot.com/185000_184445_43619_61291515_thumb.jpg
//media.diynot.com/185000_184445_43620_61353154_thumb.jpg
//media.diynot.com/185000_184445_43621_33333298_thumb.jpg
I am just an old amateur realising that "a little knowledge can be a dangerous thing".
Could someone tell me whether there is any value in adding an open vent pipe to the cold feed on an open vented DHW fully pumped system? 30 years old system. Been having a problem with air in the system, noisy pump swishing etc ( 1 yr old Grundfos 15/50 set at speed 1) and F+E tank overflowing on system start up.
System Boiler26kw and pump ( on return) downstairs with 2 zone valves on the flow serving 7rads and 11 rads respectively ( single storey bungalow) Water tank + expansion tank in loft space.
Bathroom rad downstairs appears to be connected on its flow with an auto air vent in the loft which appears to act as bleeder for the whole system. Just changed this bleed device to a float chamber type and it has helped somewhat re air. But still the pump is a bit noisy off and on. Air or something seems to be moving round the system. Rad in kitchen only partly heated ( side to side - not top to bottom) now that seems to have moved to next new rad - same thing and less hot than other rads.
Discovered minimal distance - a few mm, between water level in the expansion tank and cold feed entry so bent the arm of the ball cock assmbly and now 25mm. Have just added - 2 hrs ago, X400 for a few weeks cos there is sludge and black M in the system.
At hot, very little distance from water level and overflow in the expansion tank.
//media.diynot.com/185000_184445_43617_52511225_thumb.jpg
//media.diynot.com/185000_184445_43619_61291515_thumb.jpg
//media.diynot.com/185000_184445_43620_61353154_thumb.jpg
//media.diynot.com/185000_184445_43621_33333298_thumb.jpg
