Iso valve on central heating

[Lower]

I have a slight weep from a compression joint on an isolation valve on my central heating. The leak I can sort, but is it acceptable to have an Iso valve in a unvented central heating system?

 

[Daveydub]

Typically an unvented combi has 4 isolation valves supplied by the manufacturer. If a filter is fitted then that is 2 more. Plus 2 on every radiator. There are however several places where fitting an additional one would not be acceptable

 

[Lower]

At some point someone has t'eed off the flow and return to feed a bathroom towel rail radiator. The system works fine but we recently had a new boiler fitted and the system is running at a slightly higher pressure than before so it's shown up a weak spot.

My concern was whether standard Iso valves were suitable in a central heating system and whether I should replace them while I'm at it. Are they rated for 80 degrees?

 

[Daveydub]

Depends who made them & to what standard :

Pegler Yorkshire 15mm Manual Ball Valve

Pressure rating 16 bar at 30°C (cold), 5 bar at 120°C (hot)
If they are leaking, change them. They used to cost loads of money and be really well made but then they had to be fitted everywhere, became cheap and cheerful.
Generally you would find it difficult to buy one that was worse quality than the ones supplied with your boiler

 

[Lower]

Looks like compression joint isn't leaking after all. It's the iso valve itself that is leaking. Obvious fix then!

Thanks for your advice.

 

[Daveydub]

You're welcome