Bosch Greenstar 28i Junior heat exchanger manul vent stuck?

[dm68]

Hi all,

I'm trying to open my heat exchanger vent to remove any trapped air (after a system flush) but the wingnut only turns a few mm before stopping and no air/water escapes out of the tube outlet.

pic of wingnut in closed position:

pic of wingnut in "open" position:

As you can see from the "open" position it stops at the bottom before the angled riser to the right. I didn't want to force the wingnut too much in case I snapped it but it looks like it should turn a lot more and why no air/water is vented through the tube outlet.

Should the wingnut turn further to open the vent or is there perhaps a blockage?

Thanks

 

[dm68]

Answered this myself - I have found a youtube vid showing exactly how far it turns.

 

[nep]

Hi so to bleed the he after a re pressure of the ev do i twist it

 

[muggles]

You shouldn't be removing the casing from the boiler unless you're Gas Safe Registered

 

[nep]

its only to put a few psi in the ev to stop the 0.5 - 2.75 bar flux just water side
the ev valve is outside the cover and yes i could use a rad bleed but would that put air in the he?
will the auto air vent on the he cover it?

 

[muggles]

its only to put a few psi in the ev to stop the 0.5 - 2.75 bar flux just water side
the ev valve is outside the cover and yes i could use a rad bleed but would that put air in the he?
will the auto air vent on the he cover it?

Doesn't matter what it's for. The casing forms the safety room seal for the boiler which is there for your protection, and opening it should therefore only be done by competent people who are capable of carrying out the Regulation 26.9 checks upon completion before the boiler is used again. You will not have access to the tools required to do this

 

[terryplumb]

What problem are you experiencing ,that leads you to think that you need to do anything with the Hex vent ?

 

[nep]

Hi both im a mechanic or was from 82 to12 and have a workshop full of tools
from lathes to flywheel pullers
i also fix the mess ms make and fix pcs
but im from the gen who respect gas so i will not touch it also im not qualified, so cant
i admit ive no xp re ch other than topping up rad and cutting the condensate pipe in 08 and we were told to do that as no one was free as it was -15 and most 32mm pipes froze

okay no xp but know its the ev as every 4 years it lets a little air out, no water

after the service i notice the gauge doing the 0.5 bar cold to 2.75bar when hot
all i want to do is fill it to 14 psi and the ch to 1.2 bar

sorry for typos im controlling my pc from a 3ins phone 100 mile away
i thought setting the ev (outside the cover btw) may trap air
is that wrong

 

[nep]

https://www.diynot.com/diy/threads/greenstar-28-jnr-2006-ev-re-pressure.532331/
when i said tools not gas eng sry.
i didnt mean gas engineer specific tool, this is water side only. as only enquiring if bleeding the system would effect the heat exchanger .
hey muggles i hope you don't open your bonnet and check you're oil and fill up you're break fluid, pay us to do it. no seriously i understand your concern if it was gas i would not touch it, just wanted to know if i could do this without calling the engineer out.

 

[terryplumb]

Charging the expansion vessel would require you to drop the system pressure to zero ,by draining out water from the sealed central heating system AND LEAVING the drain cock OPEN whilst you pump up the EV pressure. That is to ensure any water in the EV is free to be expelled. You do not need to drain the entire system to drop the pressure. It is possible when draining water out of the system ,that air can enter the heat exchanger and become trapped ,but on a pressurised system its unlikely.

 

[ianmcd]

you dont need to remove the outer case or touch that manual vent, the exp vessel is behind the boiler and the scraeder valve is at the top just open a vent on a rad or some other way for the water to escape, once the system pressure is at ) , start pumping up the EV with the vent still open , when the water stops running from the drain point (you will be surprised how much will come out, then pressurise the EV to 0.8 Bar then close the drain point and add water to the system to 1 Bar, you must follow all the steps and in that order, there are no shortcuts

 

[nep]

hi so to avoid opening the cover could i ...
https://www.diynot.com/diy/threads/greenstar-28-jnr-2006-ev-re-pressure.532331/
regarding the ev 28i greenstar junior
boiler is the highest point in the system bedroom cupboard .
to save taking cover off can i drop pressure from bathroom radiator as i have many times before then repressurise the ev bleed radiator rinse and repeat with doing so will it trap air in boiler .
or could i put a couple of psi in ev when cold to raise the water pressure to 1.2 and watch when its hot. thx
its the 06 version of 28i junior so i think it has an auto bleed.
thanks ian as the boiler is highest point in the system iwas worried it might trap air, and need a engineer call out as i have no boiler experience .

 

[ianmcd]

You are not listening i told you how to do it THERE ARE MO SHORTCUTS do it correctly or get a professional i