Airlock sealed heating systems

Discussion in 'Plumbing and Central Heating' started by plumbers mate, 21 Nov 2007.

  1. plumbers mate

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    I Have a glow worm flexicom boiler and i beleive there is an air lock in the system every time i drain offf the system and refill it it does not purge the air out of the sytem? i have tried turning all the radiators off, filling the system and opening whilst bleeding one rad at a time no joy the pump is fine. will the AAV on the boiler get rid of the air if its on the Return or the flow? to test the theory i put an AAV on the flow upstairs still no joy its really getting me down now does anybody know the best way of sorting this out? just one more thing i have TRV's on all the rads but no room stat. if the boiler is air locked how can i manually purge the boiler? the mains water is passed through the flow at the boiler via the filling loop. THe system was and old open vent system and is now sealed with a condensing boiler fitted
     
  2. Breesey

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    Is the boiler high in the sytem?
    If you think you have an air lock in the boiler try cracking some of the unions, that may let air out.
    Did you put any finger vents on any high spots and/or the primary flow into DHWC?
    Did closing all but one rad and venting the pump not work?
     
  3. gas4you

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    Try pressurising the system to 3 bar temporarily.

    could be a blockage though if what you have already tried doesn't work.
     

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