Fill loop tap broken off

[SYS49152]

I have a pressured heating system and the fill loop has been working fine for many years. However recently the plastic tap on the inlet valve broke off. I think this happened because the valve has become really stiff to turn. Is there any way I can free up the valve to make it rotate more freely? There appears to be some gunk around it.

With it being on the mains water I am afraid of it breaking or sticking open. I have fabricated an small extension that I attach to it with another valve on it. This was a "just-in-case" bodge. Currently I have to use a small spanner to turn the valve to top-up the heating but not sure if it's a good idea.

 

[MeldrewsMate]

It's not a good idea to be frequently (more than once a year) topping up your system pressure.
Turn off the mains and replace that stiff valve. Then, next time the pressure is low, change the heating end valve.
In the meantime find out where all that water you've put in has gone.

 

[SYS49152]

I would normally top the system up about 2 or 3 times a year. No more.

As for where the water is going to, I've no idea. No signs of any leaks anywhere. I randomly open the hot press door a few times throughout the year and check the pressure. If it's below 1.0 bar, I top it up.

 

[ianmcd]

just replace the valve 10 min job

 

[SYS49152]

I will do.
As this is on the main water feed to the attic tank also (via a ball cock), I assume when I turn off the main supply downstairs, the water from the feed to the attic will need to be drained off? Or will it ?

 

[Jajodu]

I will do.
As this is on the main water feed to the attic tank also (via a ball cock), I assume when I turn off the main supply downstairs, the water from the feed to the attic will need to be drained off? Or will it ?

No it won't need to be drained.

 

[Madrab]

Yes, the water that is in the pipe that runs upstairs and feeds the cistern will need to be drained but it shouldn't be too much, length of pipe not withstanding, just have the container ready when you loosen off the connection and let it bleed out until it stops. Make sure the other end is shut off too so the CH doesn't drain.

I'd buy a new loop and make sure a double check ISO valve is fitted. Left valve in the pic.

 

[SYS49152]

Thank you to everyone who has posted help and suggestions above. I replaced the isolation valve today on the mains water side of the fill loop. I've attached 2 pics.

Now I realised why I had another flexi-isolation valve attached to the heating side too. The one-way valve is leaking "backwards" and dripping water from its inlet. I had to put the isolation valve there to stop it. So my next job will be to replace it. However I assume this will involve partially draining the system? I have never done that before and am a bit worried about topping the system up with too much tap water. I don't know how to add inhibitor to the system as it's sealed and all the radiators only have a tiny square bleed screw. Not big enough to apply inhibitor I would guess.

If you have any advice I would be grateful. Getting the valve replaced is the first concern here.

 

[Madrab]

The double check valve, left in my pic should really be on the cold mains side and the valve you fitted today put on the CH side.

 

[SYS49152]

Oh, is there any specific reason for that or is it just convention? The current installation is how my heating system was installed when the house was built just over 20 years ago, so I just assumed it was correct.

BTW where can I get the fill loop that you posted?

 

[Madrab]

The double check valve is there to protect your mains cold water, once the mains water has entered the braided hose it's not considered wholesome water any more and that's why the check valve should be on that side.

https://www.screwfix.com/p/r24-filling-loop/83905