Our plumber is depressed and suicidal!
- Thread starter amelia
- Start date
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reversed flow and return will give you system noise and air problems, as system will get too hot and start to boil before sensors detect heat from now return pipe. Also if its doing it on hot water as well it aint going to be that the rads being blocked
Thanks for sticking with this guys.
The boiler is an Ideal Icos. Yes, it's a sealed system. The item I was referring to that didn't have the correct pressure originally is the expansion vessel (girly description = bright orange object above boiler!). Our heating engineer replaced it eventually because he thought it may be faulty.
One thing I omitted to mention before - the boiler is fitted in the loft. I have had a niggling feeling - are our problems something to do with this fact? Can this be a problem sometimes?
Our chap is coming yet again tomorrow to flush the last lot of chemicals out so that we can leave the system to settle a bit, then send of a water sample to the lab. I hope the cheaper testing (£25) will be adequate.
I just wish you could hear the noises we are getting. One of them comes from above in the loft first thing when the sytem switches on and sounds like someone tapping the bottom of a plastic drink bottle with the pad of their finger (yes, you try it!)
The boiler is an Ideal Icos. Yes, it's a sealed system. The item I was referring to that didn't have the correct pressure originally is the expansion vessel (girly description = bright orange object above boiler!). Our heating engineer replaced it eventually because he thought it may be faulty.
One thing I omitted to mention before - the boiler is fitted in the loft. I have had a niggling feeling - are our problems something to do with this fact? Can this be a problem sometimes?
Our chap is coming yet again tomorrow to flush the last lot of chemicals out so that we can leave the system to settle a bit, then send of a water sample to the lab. I hope the cheaper testing (£25) will be adequate.
I just wish you could hear the noises we are getting. One of them comes from above in the loft first thing when the sytem switches on and sounds like someone tapping the bottom of a plastic drink bottle with the pad of their finger (yes, you try it!)
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An update!
Have just received water analysis from Purimachos.
In brief.....
Net chloride 37ppm = corrosive
Iron content too high at 9ppm
Aluminium too high at 5ppm
System is forming scale with moderate mains potential.
Is this the answer?
Heating engineer flushed system out yet again and left it to settle prior to water testing. Within 10 days (usually it's within 24 hours) air in system - noisy hot water and rads. Bled bathroom rad for what seemed like 1 minute!
Have just received water analysis from Purimachos.
In brief.....
Net chloride 37ppm = corrosive
Iron content too high at 9ppm
Aluminium too high at 5ppm
System is forming scale with moderate mains potential.
Is this the answer?
Heating engineer flushed system out yet again and left it to settle prior to water testing. Within 10 days (usually it's within 24 hours) air in system - noisy hot water and rads. Bled bathroom rad for what seemed like 1 minute!
What pressure do you see on the boiler gauge when the system is first filled up, bled and pressurised? later, after air has 'appeared'?
It's very difficult to grasp what's going on here because air can only enter a system (through a leak, etc) if the pressure inside is lower than atmospheric. Yet in your case, air gets in in hours / days in large quantities! Could it be getting in because water is leaking out? With the boiler at a 'high point' (in the loft), if the pressure in the system drops air will enter through the auto-air-vent inside the boiler. Could there possibly be an internal leak in the hot water cylinder? This would account for the 'invisible' loss of water and subsequent entry of air into the (now) under-pressurised system.
I guess you've been through all this already!
It's very difficult to grasp what's going on here because air can only enter a system (through a leak, etc) if the pressure inside is lower than atmospheric. Yet in your case, air gets in in hours / days in large quantities! Could it be getting in because water is leaking out? With the boiler at a 'high point' (in the loft), if the pressure in the system drops air will enter through the auto-air-vent inside the boiler. Could there possibly be an internal leak in the hot water cylinder? This would account for the 'invisible' loss of water and subsequent entry of air into the (now) under-pressurised system.
I guess you've been through all this already!
Pressure is 2 or 3 notches over 1 bar when cold. System starts getting noisy so I bleed the rad in the bathroom (usually). Pressure drops - top up - pressure back to normal - we're back to square one. The whole cycle starts again usually within 24 - 48 hrs (noise etc) although since all the chemicals have been flushed out it's taken longer.
Our heating engineer, as I said in a previous post, wants to change the hot water cylinder as he thinks that's where the problem could be. We have no signs of a leak anywhere, but we have the problem of concrete floors downstairs. I would have thought we would still have some indication, particularly as heating is off at the moment. We are reluctant to go for cylinder replacement (£150) as we can't afford it, but he will fit it free of charge, to get rid of us!
Thanks for your interest croydoncorgi.
Our heating engineer, as I said in a previous post, wants to change the hot water cylinder as he thinks that's where the problem could be. We have no signs of a leak anywhere, but we have the problem of concrete floors downstairs. I would have thought we would still have some indication, particularly as heating is off at the moment. We are reluctant to go for cylinder replacement (£150) as we can't afford it, but he will fit it free of charge, to get rid of us!
Thanks for your interest croydoncorgi.
With the system pressure consistently above 1 bar, with the boiler in the loft at the top of the system, it's virtually IMPOSSIBLE for air to be drawn into your system! There should be nowhere where the pressure is below atmospheric, even allowing for pump suction.
BUT if the pressure DOES drop when the boiler starts up and valves open, pipes get hot, etc. THEN the cylinder definitely need looking at.
With the boiler at the top and concrete floors hiding pipes at the bottom, this is probably the last place to look for air leaks IN - the pressure will always be too high at ground level for this to happen. But if water is leaking OUT into the concrete, then air will get drawn in somewhere else.
BUT if the pressure DOES drop when the boiler starts up and valves open, pipes get hot, etc. THEN the cylinder definitely need looking at.
With the boiler at the top and concrete floors hiding pipes at the bottom, this is probably the last place to look for air leaks IN - the pressure will always be too high at ground level for this to happen. But if water is leaking OUT into the concrete, then air will get drawn in somewhere else.
The saga continues!
Our heating engineer has - following the report on the water sample - taken every rad off, flushed the gunk out and the pipes through. We were amazed at the amount of sludge and the thickness of it considering the system has been Powerflushed twice, drained, refilled twice and had cleaner through it too.
All was quiet for 3 weeks on hot water only. Have just started running the CH for an hour a day to see how things are and to our disappointment we are back to square one. Rads are extremely noisy - gurgling spluttering etc when CH starts up. 3 of the upstairs rads are reluctant to heat up, but eventually do so, starting hot at the top and gradually warming through to the bottom. The pressure still stays a couple of notches over 1 bar and I can still bleed some air from upstairs rads. Pressure rises to just under 2 when heating. I'm at the end of my tether, as is our heating guy. He simply doesn't know what to do next.
Someone please help!!!
Our heating engineer has - following the report on the water sample - taken every rad off, flushed the gunk out and the pipes through. We were amazed at the amount of sludge and the thickness of it considering the system has been Powerflushed twice, drained, refilled twice and had cleaner through it too.
All was quiet for 3 weeks on hot water only. Have just started running the CH for an hour a day to see how things are and to our disappointment we are back to square one. Rads are extremely noisy - gurgling spluttering etc when CH starts up. 3 of the upstairs rads are reluctant to heat up, but eventually do so, starting hot at the top and gradually warming through to the bottom. The pressure still stays a couple of notches over 1 bar and I can still bleed some air from upstairs rads. Pressure rises to just under 2 when heating. I'm at the end of my tether, as is our heating guy. He simply doesn't know what to do next.
Someone please help!!!
personally i would start looking around the boiler for any sign of air being sucked in,i have never fitted or worked on this model but have had a similar prob which took a lot of patients on both sides to resolve which it was.after much grief we found that the sys was sucking air through the aav and glands of the lockshield valves causing noises,the tapping noises sound like expansion hope this may be of help.
There was a somewhat similar story on another forum where aguy eventually found that by running thesystem at a higher pressure (in his case above 1.4 bar) it didn't collect air any more.
He had tried a lot of things, but it seems he had a micro-leak which let air in , unless the pressure was high enough. I'd increase the pressure in the pressure vessel to say 1.5 bar and run the system at nearly 2 bar cold to see if there's any difference.
As I'm sure you know , if it gets to about 3 bar hot then the prv will open and let water out.
He had tried a lot of things, but it seems he had a micro-leak which let air in , unless the pressure was high enough. I'd increase the pressure in the pressure vessel to say 1.5 bar and run the system at nearly 2 bar cold to see if there's any difference.
As I'm sure you know , if it gets to about 3 bar hot then the prv will open and let water out.
Thanks for your input. I am the eternal optimist - I believe there is a solution to everything so we will just have to keep trying..........
Have just discovered that if I've run off some hot water ie bath, washing machine etc and then the CH starts for the first time, it is quiet!
Can anyone explain?
Also - our hot water cylinder has an immersion heater, from when we had the oil boiler system previously, which I don't think I've ever mentioned during this tale. Didn't know if this is relevant.
I know, I know, I'm clutching at straws.......
Thanks for reading this.
Can anyone explain?
Also - our hot water cylinder has an immersion heater, from when we had the oil boiler system previously, which I don't think I've ever mentioned during this tale. Didn't know if this is relevant.
I know, I know, I'm clutching at straws.......
Thanks for reading this.
Have you definitely, absolutely, completely checked RETURN pipework near the boiler for leaks? And is the automatic air vent inside the boiler definitely operating?
With the boiler at the top of the system, the pump built into it, and the system pressure over 1 Bar, it's hard to see how pump suction could be pulling the pressure below atmospheric and letting air in somewhere, but seems to me it's the only explanation left.
There may be a problem with the AAV too, if air is indeed being drawn in through a microleak in the return pipework and then getting into the rads. With the AAV working, it should vent out as fast as it leaks in!
Try raising the system pressure a bit (NOT above 1.75 Bar). If the problem reduces or goes away, then an air leak is favourite.
With the boiler at the top of the system, the pump built into it, and the system pressure over 1 Bar, it's hard to see how pump suction could be pulling the pressure below atmospheric and letting air in somewhere, but seems to me it's the only explanation left.
There may be a problem with the AAV too, if air is indeed being drawn in through a microleak in the return pipework and then getting into the rads. With the AAV working, it should vent out as fast as it leaks in!
Try raising the system pressure a bit (NOT above 1.75 Bar). If the problem reduces or goes away, then an air leak is favourite.
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