Sealant for external flue run.

[mutley racers]

Hi all. Got to run a Vailliant flue externally and been told by vailliant I need a heat resistant flexible silicone. Can anyone recommend which silicone to go for? Cheers

 

[ShaunCorbs]

I use this

High Temp. Silicone Sealant Clear - 310ml

REGZ36 - High Temperature Silicone Sealant Clear

www.regin.co.uk

 

[fowlerboi]

Interesting as I notice a job the other day with silicone round the external flue joint (worcester) and thought it had been bodged.

Never heard of sealing flue joints externally. Whats the purpose as it has a ring seal anyway?

 

[ShaunCorbs]

Interesting as I notice a job the other day with silicone round the external flue joint (worcester) and thought it had been bodged.

Never heard of sealing flue joints externally. Whats the purpose as it has a ring seal anyway?

to stop water ingress on the air side

 

[SimonG]

Gas boilers not have a rubber seal on the outer flue? Oil does.

 

[fowlerboi]

I don't think the Alpha's do but Worcester certainly do. Would be surprised if it ingresses water with it. Is it a gas safe thing or just MI's?

 

[Deleted member 120897]

Is it a gas safe thing or just MI's?

I think it’s just mi’s, as some manufacturers don’t allow white part of flue on show as they’re not uv protected.