Boiler - how to unscrew cap on fiLLing loop

[Charlie1000]

Hi,

At the weekend I bled the radiators. For a day I had lovely heating and since my Valliant ecoTEC Pro boiler has been throwing a F22 warning and no hot water.

As far as I can tell I need to fill up the water, but my filling loop is disconnected (apparently that’s modern standard now) but for the life of me I can’t work out how to remove the cap so can reconnect.

Can anyone help?

 

[Mottie]

Fitting loop? Loving hearing? Lol. Someone’s been using an iPad with auto correct - been caught before on that and you have to check carefully before posting!

As for the cap, my filling loop is permanently connected with a valve at either end but there is a metal cap tethered to the mains pressure end which just screws on/off of the valve when the loop is removed. Here’s my one - a picture of yours would help.

 

[John D v2.0]

Basically it will screw on, but it's possible it's seized up. You might need to tap it a bit, or use mole grips

 

[lt8480]

Looking at the picture supplied I would expect a ~30cm flexible pipe to be located somewhere. It is often left connected at one end to a valve/tap.

If the above is the case you will need to unscrew the cap pictured, connect the flexible pipe and open the valve/tap above as well as a valve that will exist on the other end of the flexible pipe.

E.g. http://i1198.photobucket.com/albums/aa451/MrPointy1/FillLoop1.jpg~original

Once the correct pressure is reached both valves should be re-closed and the flexi-pipe disconnected.

(Some boilers, e.g. Atag, have a designed fitting rather than a flex-pipe between two points on the boiler. But this doesn't appear to be the case but hard to tell from the photo supplied).

The filling loop shouldn't be left connected - if the valves fail/leak the system will slowly over-pressurise as the mains water will be higher pressure than the heating system; or, say if the mains water goes off the radiator water will leak back into the tap water once the mains pressure drops below the boiler pressure. Not sure who did Motman's boiler but it's not recommended as a failed valve will cause a headache.

The caps are basically there to stop dirt etc. getting in and in case of valve failure.

As John D v2.0 said the cap may be seized and need grips to loosen but it should simply unscrew.