Constant air in radiators
- Thread starter DALDavies
- Start date
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Either you have a leak somewhere, check for drips when the pump is not running. If not, the pump is drawing air from the vent pipe, the correct layout is in order of flow: vent, cold feed, pump. Alternatively, your f&e tank (the smaller one in the loft) is running dry. These are the most common faults so best to check them first.
There are several ways that air can get into a system:-
1, Pulling down the open vent( caused by poor pipework configuration or blockages around feed/vent connections into system)
2, Micro leaks(usually upstream of pump)
3, It may not be air, but hydrogen formation due to the corrosion process.
If you can light the "gas" coming from the rads, its hydrogen. confirm or disprove that and come back.
1, Pulling down the open vent( caused by poor pipework configuration or blockages around feed/vent connections into system)
2, Micro leaks(usually upstream of pump)
3, It may not be air, but hydrogen formation due to the corrosion process.
If you can light the "gas" coming from the rads, its hydrogen. confirm or disprove that and come back.
Pump/Open vent/Cold Feed configuration.
On flow pipe should run from boiler open vent first (this pipe goes up and over the tank) Cold feed (connected into the tank at the bottom) both should not really be more than 6" apart then into the pump.
Secondly blocked or restricted cold feed causing air to be dragged in through the open vent pipe.
Thirdly a leak causing fresh oxygenated water constantly being pulled in from the tank
Forth pump speed too high for system requirements
Fifth Not air hydrogen gas caused by system corrosion (can be tested by holding a lighter by a radiator bleed if it lights it's hydrogen)
AVOID BLEEDING A SYSTEM WITH PUMP RUNNING
On flow pipe should run from boiler open vent first (this pipe goes up and over the tank) Cold feed (connected into the tank at the bottom) both should not really be more than 6" apart then into the pump.
Secondly blocked or restricted cold feed causing air to be dragged in through the open vent pipe.
Thirdly a leak causing fresh oxygenated water constantly being pulled in from the tank
Forth pump speed too high for system requirements
Fifth Not air hydrogen gas caused by system corrosion (can be tested by holding a lighter by a radiator bleed if it lights it's hydrogen)
AVOID BLEEDING A SYSTEM WITH PUMP RUNNING
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You were quicker than my essay 
It appears that the pump is on the return line. I have yet to establish the position of the vent and supply from the header tank in relation to the pump.
The air from the rads is not ignitable.
There is water in the feeder tank.
The air from the rads is not ignitable.
There is water in the feeder tank.
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