Trapped air in heating system

[oilboffin]

Wheres the tundish

 

[Chippy99]

Bottom left - you can't see it because it's behind the lagged pipework. The relief pipework is the same as on the previous install, it's just the tundish is now a bit lower down, to make it lower than the p&t relief on the new install. On the old tank there were seperate p & t relief valves and they were on the LHS, hence the tundish on the left. Moving the relief pipework would be a major job.

So I accept some "compromises"; it's not like a new, blank sheet of paper install...

 

[dilalio]

BUt it has to follow MIs and doesn’t!
Just do as @ianmcd has said and opening the gate valve a quarter or two. And get BG to sort the discharge! It’s their duty to do it as per MIs else your warranty is void!

 

[Chippy99]

I'll get BG to fix the discharge - I did say I would, and thanks for the advice.

The gate valve was already fully open. Should it be?

Regards the warranty, seriously the tundish is of course not in any way attached to the tank, so there's no way Gledhill could invalidate a warranty for that. My solicitor assures me The waste pipe to the tundish is a bit long, but the waste pipe from the tundish is 1" and the spec only requires 3/4", so I am not too worried about it.

I am VERY reluctant to get BG to re-plumb the whole system, simply because a bit of waste pipe is 300mm too long! The concept of "reasonableness" has to apply, not to mention my great reluctance to have our water off for another day and engineers' muddy shoes up and down stairs all day... again. It's not that I don't want to put them out; it's that I don't want them to put me out!

If there's a serious fault, it needs fixing and I'll get it fixed. If it's trivial, I don't think I'll bother. Now, back to the question, should the gate valve be fully open, half open or closed? What's it for and what's the correct setting?

Thanks once again.

 

[Chippy99]

OK after some googling, I think the gate valve is to allow a little water to flow through the boiler when all other paths are shut?

Should it be fully open, or half open?