Refilling the sealed system Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[greengrass]

Established in the end its a sealed system by the top up/fill loop hose.

Filling a sealed C/heating system via top up loop [the only place I can find that would fill it, I hope]

It's the pain in the a**e back for the last time on this subject.
Coming to the end of how to do it so I can take notes for when the job is done and will impress my son - in -law as I won't tell him I'll let him think I know it all.
The loop is a flexi hose connection I assume used to top the system up when required. As this seems to be the only method of recharging the system I'll be doing it following replies. T
he tap on the hose is similar to the dishwasher/washing machine tap/s. Turning it on and I am assuming this will fill the system [in time].

However is there anything else I should do other than bleed the rads of air. I should say what I think is an air displacement valve in the airing cupboard on the central heationg pipe would just bleeding from that poiint be sufficient to expell all air out of the pipes and rads? or is there something elsel to be done? He said that when pressure gauge drops on the boiler he has to open this valve to bring up the pressure.

Greengrass

[htg engineer]

Yes the flexi hose has to be connected to both valves, one is the cold feed and one in the heating return pipe fitted with a non-return valve. This prevents any contaminated water entering the mains water supply.

Re-pressurising the sytem should only take 30 or so seconds, pressurise to 1bar and vent radiators, then re-pressurise to between 1.0bar - 1.5bar. You can also vent the pipe you mentioned, that is in the airing cupboard.

That should be all you have to do, if there's alot of air in the sytem you can vent the radiators again after a few days and top-up the pressure.

Remember to have heating turned off when venting radiators.

[greengrass]

Thanks htg engineer
working on it today [Mon]