Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: TD on 19 February 2017, 10:30:12
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Radiator upstairs was cold....I thought perhaps the TRV had stuck shut....but thought I would check for air first...
Completely full of air....so much in fact the pressure in the system dropped from just under 3 bar to just over 1 bar...so I topped it back up to about 2 bar...
So wheres that air come from in a sealed system? :-\
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Pressure should be 1.5 bar max,just drain some water out a rad up stairs till you get pressure down,never bleed rads with heating on :y
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Pressure should be 1.5 bar max,just drain some water out a rad up stairs till you get pressure down,never bleed rads with heating on :y
Not on mine....min is 1.2 bar max is 3 bar, so 2 bar is about in the middle and if the pressure does go over 3 bar, it will release the pressure itself :y
I'm more intrigued as to where the air came from :-\
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Pressure should be 1.5 bar max,just drain some water out a rad up stairs till you get pressure down,never bleed rads with heating on :y
Not on mine....min is 1.2 bar max is 3 bar, so 2 bar is about in the middle and if the pressure does go over 3 bar, it will release the pressure itself :y
I'm more intrigued as to where the air came from :-\
We had a similar issue when our Vaillant combi was first fitted...pressure drop kept tripping the boiler off. Solution ended up being the installation of, iirc, a bladder in the boiler somewhere :-\ apparently it was a flip of a coin as to whether it would be needed or not when it was first installed. Plumber obviously called tails.
Not happened since.
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When did it last have any inhibitor?
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When did it last have any inhibitor?
I would guess when it was installed....so 2 1/2 years ago .... I could pop the magnaclean off and fill it with more inhibitor....if you think It would need it after this period of time :-\
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When did it last have any inhibitor?
I would guess when it was installed....so 2 1/2 years ago .... I could pop the magnaclean off and fill it with more inhibitor....if you think It would need it after this period of time :-\
I think what Mark is implying, is that the 'air' is self generating if there's no/not enough inhibitor in the system
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Trap a bit of the recovered air in a container and try lighting it
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Trap a bit of the recovered air in a container and try lighting it
Electrolytic corrosion releases hydrogen & oxygen.
The oxygen tends to pair up with iron to produce more iron oxide. The hydrogen doesn't.
If you do capture some hydrogen try not to set the curtains alight.............
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Trap a bit of the recovered air in a container and try lighting it
what about lighting it at the rad as you bleed it .... ::)
Don't let The Boy try it ::) ::) ::) ::)
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Trap a bit of the recovered air in a container and try lighting it
Bit late now....as ive bled the rad....with have to monitor it, to see if the air comes back......
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Pressure should be 1.5 bar max,just drain some water out a rad up stairs till you get pressure down,never bleed rads with heating on :y
Why is that? You would think similar to a car that you need pressure to push the air out when you open the valve.
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Trap a bit of the recovered air in a container and try lighting it
what about lighting it at the rad as you bleed it .... ::)
Don't let The Boy try it ::) ::) ::) ::)
Done that a few times!
But a small bottle or similar to carry out the 'pop test' as per school science is a better bet
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Pressure should be 1.5 bar max,just drain some water out a rad up stairs till you get pressure down,never bleed rads with heating on :y
Not on mine....min is 1.2 bar max is 3 bar, so 2 bar is about in the middle and if the pressure does go over 3 bar, it will release the pressure itself :y
I'm more intrigued as to where the air came from :-\
This might be part of the problem. You will have air dissolved in the water in the system from the start. Once that air has been purged, there shouldn't be the need to bleed constantly unless the system is deteriorating through lack of inhibitor. A good inhibitor will contain deoxygenating chemicals to promote this.
If you are having to top up regularly, you are introducing fresh water containing air, so will also be bleeding regularly.
As to the correct pressure to run the system at, it's not an arbitrary choice. The system will contain a pressure vessel inside which an air bladder is charged to a certain pressure. As the system reaches this pressure, the pressure vessel will start to contain the expansion of the water in the system by compressing air in the bladder. This will limit the pressure rise as the system heats.
You really only want to adjust the pressure when the system is stone cold, and you should set it to about the same pressure as the charge in the air bladder. Typically, this will be not more than 1.5 BAR although how it was set at installation depends on the system. Set it to a higher pressure and you have used up some or all of the expansion volume available in the pressure vessel so when the system heats up you may have a problem. If you run out of expansion space the system will hit 3 BAR when it's hot and blow off the relief valve. You'll then notice the pressure has dropped when it's cold and top it up again, and so begins the cycle that admits air and waters down the inhibitor.
Furthermore, if the relief valve operates regularly, it'll only be a matter of time before it gets a bit of crud stuck in it and starts weeping, meaning you'll keep topping up, and keep bleeding...
Another issue is where the bladder in the expansion tank has punctured. The expansion volume of air leaks away (maybe ending up in a radiator) ;) and you top up the system but end up with no expansion space. So, you top up to maybe 1 or 1.5 BAR cold, and as soon as the system warms up it rises quickly to 3 BAR and lifts the relief valve. Once it cools down, there is nothing to take up the contraction of the water, so it'll draw air in, often through an automatic bleed valve or a weak joint, or the hole in the expansion tank bladder, and you'll be bleeding regularly to remove it...
In your position, I would bleed all the radiators, set the pressure to 1 BAR when it's stone cold, and watch what happens when it warms up. I would expect the pressure to rise to 1.5 BAR or so, and to drop to 1 BAR again when cold. I would expect that it doesn't need any further filling or bleeding. If it does, or if the pressure strays outside those limits, something's not right.
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Popped in screwfix earlier and bought 1L of inhibitor.
Popped the top of the magnaclean. Hardly anything on the magnet. Managed to get about 300ml of the inhibitor in. If I were a betting man, I'd bet this was the way the plumber who fitted the boiler did it too....so it probably didn't have enough in it.
Over the next fews days I'll get the other 700ml in the system :y
Oh and I managed to find the install instructions for the boiler....it says anything between 1 and 2 bar is fine at cold....its 1.3 bar atm cold ...so ill leave it alone I think :)
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Yep, sounds OK.
If you have any more issues, it would probably be a good idea to find the pressure vessel (often integrated into a combi boiler) and check the pressure on the air bladder.
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Yes.exactly as Kevin suggests. However If the pressure vessel is u/s it is sometimes an expensive and time consuming job to replace the vessel and you can fit a remote vessel kit anywhere convenient in the pipe work.usually on the return line.