Repressurizing the boiler with external filling loop

10 Feb 2011
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United Kingdom
I have a Glow Warm Felxicom which is displaying 0.4 for system pressure. Hot water/ heating are still working but on the label it says to repressurize if it goes below 0.5. There is no filling loop below the boiler, but there is what looks like one in the next room by the water tanks. I seem to remember that this was confirmed by a previous plumber. I just wanted to confirm the correct procedure to repressurize the boiler in this instance. I understand I have to turn one screw very slighly first and then the other until I hear the water. Do I open the one first furthest away frm the main pipe, or does it matter which one I open first? Also, the gauge next to the loop seems to display a different pressure than the digital display on the boiler itself, which one should I look at?

Thank you



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Open the one on the left, nearest the pressure gauge fully, then open the other enough to hear the water passing through this valve, use the boiler gauge to monitor and increase the pressure to say 1.3bar (cold) or whatever the maker recommends.
Thanks. I have just tried and the second screw (N2) didn't move. I did not force it at all, but was thinking of putting a bit of wD40 first, would that be the way to go


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Last edited:
Try exerting a bit more pressure on the screw
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Yes, more torque, if unable to turn with S.driver alone clamp a vise grips on the S.driver shaft and turn it while holding it firmly in place in the valve spindle slot.
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