central heating pressure drop help

[moss99]

Hi , i have had a pressure leak on my central heating system , it became more noticeable recently with the cold weather , i tracked it down this evening to a valve in my boiler , a grant vortex pro external .
See video of leak

photo :

https://www.dropbox.com/s/g9bxrw7hlk23lh4/InkedPhoto 05-03-2018, 8 36 12 pm_LI.jpg?dl=0



It was leaking under the large nut ,,. see photo ( green arrow ) i managed to tighten it a bit and the leak seemed to stop , it looked like it had been leaking around the tap nut (red arrow ) so i tried to tighten it a bit . Bad idea it started spraying water out around the seal .
I got some towels out straight away and bled the pressure from the system .
i took the tap nut off and it was badly corroded around the sealing face , i was surprised not to see a copper sealing ring or something .
should i replace the valve or try to wire brush the sealing faces off and use some ptfe tape on the threads ?
any advice would be appreciated .

 

[muggles]

Just replace the valve - they're not expensive

 

[moss99]

I have bought 2 , should I use the existing olive and nut on the 22mm side or try and get it off.
Also should I be concerned about the water that leaked over the boiler ,?

 

[ianmcd]

if the thread is the same just use the existing olive and nuts, not all valves have the same thread though, you will know straight away if they are different

 

[Terrywookfit]

I'm surprised it's not the Wilo pump that's leaking.

 

[CWHEATING]

More than likely it’s just the seal that perished.Isolate each valve but firstly take note which way the arrow is pointing on pump. Remove pump, change both seals while pump is removed because why not. Reinstall pump making sure the arrow is pointing the correct way. Open valves slowly check for leaks. I’d satisfied open center but with a slotted screwdriver to remove air. Fire up boiler.

 

[moss99]

ok , i replaced both valves and refilled the system , i did notice an air leak as the system was refilling and water started to leak a lot around the large nut , (not the same side as the initial leak )
I had to put a lot of force to tighten it on the large nut but it did seal , it did come with fibre washers which i also put silicone grease on .
this morning i still have pressure . .
I am going to drain it over the weekend to add fernox MB-1 do you think its worth getting some rubber washers to replace the fiber ones ?

It was fibre seals which failed . The whole system is less than 3 years old and cost me around £11,000 , I was assured high quality parts were use throughout .

 

[CWHEATING]

Fibre seals are rubbish. Rubber seals that usually come with the pump are the best option. No need for silicone grease.Best option would be to use a jointing compound paste with your fibre seals.