Low Pressure and leaking filling loop.

17 Dec 2012
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Newcastle upon Tyne
United Kingdom
Started to have problems a few days ago with radiators particularly upstairs getting warm to hot at the bottom and cold at the top. Did a bit of googling and then checked pressure on the boiler, it's reading less than 1bar when running. I searched here and the advice is to turn the valve on the valve on the filling loop slowly to increase pressure but as soon as I start turning the valve water starts dripping either from the end of the loop pipe or the valve, this happens when turning it either way with single spot where it doesn't leak. Any advice or comment would be appreciated.

I'm assuming the filling loop is the bendy non-connect pipe 2nd from the right? It's an Isar combi boiler by the way.


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Not sure if I am reading you post correctly. Did you connect the open end of the hose before turning on the taps to re-pressurise?

Remove the chrome cap from the fitting immediately next/below where the hose screws into it's fitting. Screw the open end of the hose onto this fitting and turn both black tap handles on until the pressure guage reaches approx 1.2bar.

You need to do this with the boiler and system cold. ;)
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