I wasn't trying to bypass you! Yes, we haven't got to the bottom of it yet.
To follow JohnTheo's comment, the pump should be at the lowest setting that does the biz. For a small system like yours, almost certain to be minimum setting.
Open system sucking in air, closed system still sucking in air! Any help or pointers?
- Thread starter kugaman1
- Start date
To follow JohnTheo's comment, the pump should be at the lowest setting that does the biz. For a small system like yours, almost certain to be minimum setting.
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I’m just trying options that are at minimal cost first of all….Ive had 3 different plumbers do jobs on the system over the years and shown them the air problem…..I thought the 3rd one who suggested pressurising it all had given me a solution…..nope! I just have pressurised air in the system now!
The first plumber teed off some high lines on the supply and return to give high level vents….made no odds whatsoever so I got them removed by the second plumber.
The problem is a difficult one and I do t want to spend too much more money on it until I can be sure of a solution!
The pump is currently sat at speed 2 ( 3 speed pump)….I will turn it down to 1 and see how that goes……
I agree that the Aladdin vents don’t find the source of the problem but if they can stop the weekly bleeding of the system in colder weather, they are cheap starting point!
Again, thanks all for your thoughts, ideas and contributions, we will get to the bottom of this at some point…
The first plumber teed off some high lines on the supply and return to give high level vents….made no odds whatsoever so I got them removed by the second plumber.
The problem is a difficult one and I do t want to spend too much more money on it until I can be sure of a solution!
The pump is currently sat at speed 2 ( 3 speed pump)….I will turn it down to 1 and see how that goes……
I agree that the Aladdin vents don’t find the source of the problem but if they can stop the weekly bleeding of the system in colder weather, they are cheap starting point!
Again, thanks all for your thoughts, ideas and contributions, we will get to the bottom of this at some point…
I'd be surprised if speed 1 isn't fine. Of course with the current weather it will take a while before you know whether it's made a difference.
A 6M UPS2 on speed 2 has a max head of 5M so around 4.5/4.8M when circulating ~ 10LPM with 7 rads, shouldn't be a problem, on speed 1 (4M) should give a head of 3.8M at the same flowrate which should be quite adequate, a 8M UPS2 on the other hand is a giant of a pump that will circulate multiples of that flowrate at a constant 7M on speed 2 and 6M on speed 1. I just wonder is this problem temperature related for whatever reason, someone on one of these websites just couldn't run their system at higher than 65C without problems despite also sealing the system, don't know if he ever got to the bottom of it.
It will be interesting to see what happens during the rest of the summer if the boiler is being used to heat the HW cylinder, if not then I would run the pump continuously cold as suggested above.
It will be interesting to see what happens during the rest of the summer if the boiler is being used to heat the HW cylinder, if not then I would run the pump continuously cold as suggested above.
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QUOTE
Yes, the boiler is used twice a day to heat the hot water. Why will that be a factor?
I’m not sure what you mean.
Its a a different circuit with different head losses but shouldn't make a difference.
Not sure if the pump is 6M or 8M, I’d assume the former.
Have a look at the label on the pump front, you might need a mirror as its very close to pipework.
Yes, the boiler is used twice a day to heat the hot water. Why will that be a factor?
I’m not sure what you mean.
Its a a different circuit with different head losses but shouldn't make a difference.
Not sure if the pump is 6M or 8M, I’d assume the former.
Have a look at the label on the pump front, you might need a mirror as its very close to pipework.
For anyone who's interested here is a Caleffi bulletin that doesn't really reflect true operating conditions but does give a flavour of what happens with different EV positioning, (PSI/1.45=M). Even if the EV is installed on the pump outlet then (IMO) the EV precharge pressure and the pump head would have to be equal to give zero pressure at the pump inlet, a OV system will certainly approach these conditions if the F&E cistern is installed to the pump outlet, you may have the pump (like mine) installed at the (oil) boiler return with the the F&E perched in the attic ~ 5M above but feeding into the manifold return at the cylinder coil return in the landing so return pipe line losses also reduces it effective static head, I run my (6M Wilo Yonos Pico) pump at a 4.6M PP head which results in a pumping head of ~ 3.5M at a circ rate of ~ 12.0LPM (all TRVs fully calling) and around 2.7M with the TRVs throttling down), one rad, mounted in the bedroom converted attic has run for over 30 years with a very slight vacuum (no water comes out the vent with system on) but never gave the slightest problem, if the vent is opened with the boiler shut down, then water issues afte a few seconds.
Incidentally, the UPS2 does have 3 PP (proportional pressure) settings (flashing green LED when the setting button is depressed for > 3 secs) but for some strange reason, these setting are, in the main, far too low, the OPs system might run just about OK on PP setting 3 which will give ~ 6LPM at a 2.0M head.
Incidentally, the UPS2 does have 3 PP (proportional pressure) settings (flashing green LED when the setting button is depressed for > 3 secs) but for some strange reason, these setting are, in the main, far too low, the OPs system might run just about OK on PP setting 3 which will give ~ 6LPM at a 2.0M head.
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Simpy put, if you have a 6M UPS2 pump then you will/should have 2 setting modes, one mode, with a solid green LED., which your pump is running on? has 3 different setting settings which should be marked I,II & III on the pump, you can change these settings by pressing the setting button briefly, setting i sets the pump speed to give a maximum head of 4.0M with no flow so your relatively small system will probably result in a head of 3.5M (ish) & a circulation rate of around 8 to 9LPM, setting II gives a max head of 5.0M so ~ 11LPM at 4.7M, setting III is still higher at 6.2M and very rarely required.
The pump will change to its other mode, proportional pressure or PP (mode) if you keep the setting button pressed for 3 to 5 secs and will be incicated by a (the) flashing green LED, this mode also has three settings, there is very littly difference in these settings, setting III, the highest only gives a 3M head with a huge flow rate of 33LPM so will probably only give you around 6LPM at a head of ~ 1.7M.
So suggest running it on fixed speed (solid green LED) on setting I to give ~ 3.5M/9.0LPM or give it a go on PP mode (flashing greed LED) on setting III which may (and only may) be sufficient at ~ 1.7M/6.0LPM
The pump will change to its other mode, proportional pressure or PP (mode) if you keep the setting button pressed for 3 to 5 secs and will be incicated by a (the) flashing green LED, this mode also has three settings, there is very littly difference in these settings, setting III, the highest only gives a 3M head with a huge flow rate of 33LPM so will probably only give you around 6LPM at a head of ~ 1.7M.
So suggest running it on fixed speed (solid green LED) on setting I to give ~ 3.5M/9.0LPM or give it a go on PP mode (flashing greed LED) on setting III which may (and only may) be sufficient at ~ 1.7M/6.0LPM
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Agreed, and that's the wrong place. Curiously, in the Calefi stuff, Fig. 5-16 has expansion tank pressure 10psi, but Fig. 5-17 has 5psi. Of course, if it had been 10psi, there wouldn't be negative pressure.
At the moment (unless it's been changed) the vessel is on the boiler return. Having had another think, I'm not sure there's anything to be gained by relocating it to the pump suction. For a given vessel pressure, the pressure at pump suction is (probably) higher with the vessel as it is, because the headloss through the boiler and pipe to the pump is likely to be less than than difference in elevation, approx 3m.
Oddly, unless I've missed it, there's nothing in the manual about water flow and boiler pressure loss.
One often reads of the need of another EV if rad numbers etc are increased, these often seem to be installed at the most convenient location. What would be the effect if the original EV was say 8L installed at the inlet to the circ pump and another 8L was installed at the pump outlet, both with the same precharge pressures.
Effect would be minimal. System water needs room to expand. Not the first time I created an air bubble in a radiator as a temporary fix or fitted additional vessel close by. Though the system water temperature will be less than specified for the vessel, have had to replace vessels where the diaphragm had failed regardless ( Worcester 240 and 280 typical example as was Vokera Linea max EV)
5 pages and still going strong. I am wondering if a system component is defective and causing the issue.
Open vented systems like one here can sometimes suck air from the header cistern when F&E is almost atop the boiler ( have successfully done that with no issues on one of my installations as space was tight). With system converted to sealed, even if a joint or a valve was liable to be letting air in, relative to atmospheric pressure, system pressure would be higher on suction and pumped sections of the system so air ingress unlikely.
It is not uncommon for towel rails to need regular evacuation, I have one in our bathroom that regularly requires bled. No other ( panel) radiator suffers from this issue.
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