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dr_g
Joined: 05 Jan 2008
Posts: 22
Location: Sheffield
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 Posted: Tue Mar 11, 2008 1:38 pm Post subject: Fernox Leak Sealer? Help! |
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Hello Again,
I have always had problems with my boiler losing pressure of a period of a few months (in the last case about 2 months from 1.2 bar to the F.25 pressure error switching the boiler off). I believe it is due to a 'micro leak' somewhere in the system. I would like to try Fernox leak selaer, but the boiler manufacturer, Vaillant, say this is not possible since it will block the boilers heat exchanger, making the boiler scrap. Fernox however say that their leak sealer is fine for all boilers including Vaillant Ecomax condensers.
The system uses Hep2O plastic pipework.
What do you think? Any comments appreciated.
Cheers,
Garth. |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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| Posted: Tue Mar 11, 2008 2:30 pm Post subject: |
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If the manufacturer say No, you would be damn stupid to do otherwise.
If you have a leak it can only get worse, so get looking in all the obvious places with the system cold.
Packing glands and rad tails.
Any auto air vents.
Fittings in hot areas, such as pump unions, boiler and cylinder.
Finally disconnect the plastic pipe and pressure test it in sections.
What is the boiler model and how old |
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dr_g
Joined: 05 Jan 2008
Posts: 22
Location: Sheffield
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| Posted: Tue Mar 11, 2008 4:59 pm Post subject: |
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| thescruff wrote: | If the manufacturer say No, you would be damn stupid to do otherwise.
If you have a leak it can only get worse, so get looking in all the obvious places with the system cold.
Packing glands and rad tails.
Any auto air vents.
Fittings in hot areas, such as pump unions, boiler and cylinder.
Finally disconnect the plastic pipe and pressure test it in sections.
What is the boiler model and how old |
Hello,
Its a Vaillant Ecomax 635. It's 3 years old. I've done all the usual checks you mentioned. The Hep2O pipework was pressure tested by a Hep2O technician before the house (new build) was finished (he said it was OK). I did have problems during installation of the pipework because the dickeaded plumber didnt push the fittings together properly (hence the pressure check). About 15 joints were faulty, but eventually we had the system up to 16 bar with no leaks. The AAV was replaced in January under extended warranty. I also fitted a Magnaclean filter. The system is filled with Fernox F1 to more than the reccomended concentration, and the water is clean. Apart from pressure loss over time the system is fine.
Cheers,
Garth. |
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straker1966
Joined: 06 Jan 2008
Posts: 164
Location: cambridge
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| Posted: Tue Mar 11, 2008 6:20 pm Post subject: |
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15 HEP2O JOINTS LEAK ON ONE NEW HOUSE!!!! GOOD LORD!
what was the clown doing wrong? you can only get 3 things wrong with them fittings...
1. not pushed home far enough
2. he put the fittings on to scratched pipe
3. no inserts.
you can buy non toxic dyes to add to the system to show up any surface leaks and you can also add artificial smells to give a rough idea where the leak is but if theres hep20 joints on beam and block floors that have been covered with a plastic sheet membrane, then you got bob hope, friendly.
i think i know your plumber- its mr Lee King from Leek,Staffs.  |
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dr_g
Joined: 05 Jan 2008
Posts: 22
Location: Sheffield
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| Posted: Tue Mar 11, 2008 10:49 pm Post subject: |
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| straker1966 wrote: | 15 HEP2O JOINTS LEAK ON ONE NEW HOUSE!!!! GOOD LORD!
what was the clown doing wrong? you can only get 3 things wrong with them fittings...
1. not pushed home far enough
2. he put the fittings on to scratched pipe
3. no inserts.
you can buy non toxic dyes to add to the system to show up any surface leaks and you can also add artificial smells to give a rough idea where the leak is but if theres hep20 joints on beam and block floors that have been covered with a plastic sheet membrane, then you got bob hope, friendly.
i think i know your plumber- its mr Lee King from Leek,Staffs. |
Number 1.
I think joint problem is sorted because at 16 bar if anything wasnt right, the joint would have gone.
Concensus is its a 'micro leak', but what can I do about it?
Cheers,
Garth. |
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straker1966
Joined: 06 Jan 2008
Posts: 164
Location: cambridge
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| Posted: Tue Mar 11, 2008 11:25 pm Post subject: |
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the word hepworth "technician"...
how long did he have the system under 16 bar test for? was it an air test or water test? how did he get the pressure that high?
ive seen john guest "technicians" and the old adage comes to mind... "they who cant do-teach"...
as for leak sealer, i know vaillant dont like leak sealer but once the boilers out of guarantee they wont be interested. personally i wouldnt add leak sealer to fix flexible plumbing leaks- i can see it working on ridgid copper but not on o ring fittings.
do you have beam and block floor with the membrane and has each radiator got a pair of hepworth tees under the screed serving it from the main heating runs ? |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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| Posted: Tue Mar 11, 2008 11:27 pm Post subject: |
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I disagree with your reasoning 
A plastic pipe will leak at 1.2 bar but not at 16bar.
Why I hear you ask, because the pipe expands with pressure and the joint becomes tighter, in fact testing at that pressure is stupid, and is nothing short of a sales gimmick.
I would even go as far as saying the pipe expanding can damage the O ring, when the pipe goes back to its normal size the o ring will be stretched |
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straker1966
Joined: 06 Jan 2008
Posts: 164
Location: cambridge
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| Posted: Tue Mar 11, 2008 11:42 pm Post subject: |
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bung the leak sealer in...f.25 come up when the pressure drops to 0.4 bar so from 1.25 bar to 0.4 bar in 2 months aint alot.
bung it in i tells yer!  |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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| Posted: Tue Mar 11, 2008 11:53 pm Post subject: |
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| Before you do try taking the rad key away from Mrs Dr g |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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dr_g
Joined: 05 Jan 2008
Posts: 22
Location: Sheffield
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| Posted: Wed Mar 12, 2008 10:01 am Post subject: |
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| thescruff wrote: | I disagree with your reasoning
A plastic pipe will leak at 1.2 bar but not at 16bar.
Why I hear you ask, because the pipe expands with pressure and the joint becomes tighter, in fact testing at that pressure is stupid, and is nothing short of a sales gimmick.
I would even go as far as saying the pipe expanding can damage the O ring, when the pipe goes back to its normal size the o ring will be stretched |
thescruff, straker1966,
Testing to 16 bar is far from stupid. In fact Hep20 suggest pressure testing up to 18 bar.
I understand all about low and high pressure testing. It was not a sales gimmick - The technician suggested it in order to find any more bad joints (ie not pushed together). 1.2 bar will not break a joint, because the o-rings can withstand about 3 bar without any other restraint. Let me assure you that a plastic pipe WILL leak VERY badly at 16 bar if it has not been pushed together whereas at 1.2 bar it may not leak at all.
Regarding damage to the o-ring: unless it had been forced out of its seating (which it cannot do by design), the amount of deformation in Hep2o pipe under 16 bar pressure is miniscule compared with how much a neoprene o-ring can elastically deform.
The test was performed with water, and the technician seemed to be very knowledgeable. *Infinitely* more so than my first, CORGI registered, experienced, dickheaded 'Plumber' who, unfortunately for me, 'did' rather than 'taught' !
Regards,
Garth. |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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| Posted: Wed Mar 12, 2008 11:13 am Post subject: |
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thescruff, straker1966,
| Quote: | | Testing to 16 bar is far from stupid. In fact Hep20 suggest pressure testing up to 18 bar. |
It's stupid and unnecessary
| Quote: | | I understand all about low and high pressure testing. It was not a sales gimmick - The technician suggested it in order to find any more bad joints (ie not pushed together). 1.2 bar will not break a joint, because the o-rings can withstand about 3 bar without any other restraint. Let me assure you that a plastic pipe WILL leak VERY badly at 16 bar if it has not been pushed together whereas at 1.2 bar it may not leak at all. |
You may well understand all about high and low pressure testing, you don't show it, and you obviously know nothing about the properties of plastic pipe.
1.2bar will not break a joint, why is it leaking now, and why didn't it show at 14 bar, because the pipe will be over 1mm bigger at that pressure, and therefore the seal will be tighter.
There is more to testing an pipe than checking if it has been installed correctly, an score in the pipe for example is the most common problem, especially if it has been threaded through joists, again the bigger the pipe the least likely it will leak.
| Quote: | | Regarding damage to the o-ring: unless it had been forced out of its seating (which it cannot do by design), the amount of deformation in Hep2o pipe under 16 bar pressure is miniscule compared with how much a neoprene o-ring can elastically deform. |
An O ring will/does flatten permanently with compression, it will not re-shape, pressure test an length of pipe at room temperature and measure it.
Plastic pipe will increase in size with temperature and reduce to it's original properties when it cools, it actually needs this cooling period or it will be permanently damaged, reducing its life considerably.
| Quote: | | The test was performed with water, and the technician seemed to be very knowledgeable. *Infinitely* more so than my first, CORGI registered, experienced, dickheaded 'Plumber' who, unfortunately for me, 'did' rather than 'taught' ! |
Being a member of the kennel club is not an guarantee of quality, no more than the safety certificate from Corgi means the system is safe, they have not seen it or done any checks, the certificate is therefor dangerous and misleading.
Talking of knowledgeable technician, the boiler manufacturer say NO, you cannot use leak sealer on their boiler, and yet you are not considering their advice as valid, because Fernox say it's ok.
You have a couple of choices.
Ignore the manufacturer and risk wrecking the boiler.
Finding the leak, maybe with the aid of a dye.
Living with what you have and continue to aid fresh water, and topping the inhibitor up once a year.
Installing an devise that will top it up automatically and checking the inhibitor once a year.
john thescruff |
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dr_g
Joined: 05 Jan 2008
Posts: 22
Location: Sheffield
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| Posted: Wed Mar 12, 2008 4:45 pm Post subject: |
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thescruff
| thescruff wrote: | thescruff, straker1966,
| Quote: | | Testing to 16 bar is far from stupid. In fact Hep20 suggest pressure testing up to 18 bar. |
It's stupid and unnecessary
Then why do Hep2O recommend it?
How would you propose checking the integrity of a system that can withstand 3 bar even when incorrectly fitted?
The reason you test to this pressure is, as I said, to check for bad joints, not necessarily to detect micro leaks.
The reason you have to test at more than, say 3.01bar, is that some joints may be fitted such that the metal teeth are partially engaged, but with a very short length of pipe, and may withstand much more than 3 bar, but still not be pushed fully home. 18 bar will find the majority of bad joints by ripping any partially engaged teeth through the plastic. You go to 18 bar cold to simulate a hot condition, since heat softens the plastic making pull-out easier.
I think you are getting confused between the test for bad joints also being a test for micro leaks. This is obviously not the case. The reason I elaborated on the test procedure was because Straker1966 asked about it.
| Quote: | | I understand all about low and high pressure testing. It was not a sales gimmick - The technician suggested it in order to find any more bad joints (ie not pushed together). 1.2 bar will not break a joint, because the o-rings can withstand about 3 bar without any other restraint. Let me assure you that a plastic pipe WILL leak VERY badly at 16 bar if it has not been pushed together whereas at 1.2 bar it may not leak at all. |
You may well understand all about high and low pressure testing, you don't show it, and you obviously know nothing about the properties of plastic pipe.
On the contrary, indeed you seem to contradict much of the advice and technical data given by the manufacturer of the pipe in question, and their own technician. As I said I think you are confusing the reason for the tests I did. I know I have a micro leak. I know that the pressure test would not necessarily have detected them.
1.2bar will not break a joint, why is it leaking now, and why didn't it show at 14 bar, because the pipe will be over 1mm bigger at that pressure, and therefore the seal will be tighter.
I never said that the 16 bar test was a check for micro leaks. I said it was to check for bad joints.
There is more to testing an pipe than checking if it has been installed correctly, an score in the pipe for example is the most common problem, especially if it has been threaded through joists, again the bigger the pipe the least likely it will leak.
Yes, I know.
| Quote: | | Regarding damage to the o-ring: unless it had been forced out of its seating (which it cannot do by design), the amount of deformation in Hep2o pipe under 16 bar pressure is miniscule compared with how much a neoprene o-ring can elastically deform. |
An O ring will/does flatten permanently with compression, it will not re-shape, pressure test an length of pipe at room temperature and measure it.
Permanent compression of a neoprene o-ring depends on pressure, temperature AND time. The test was performed cold for a period of minutes. This is not long enough to cause permanent damage. Do you really think Hep20 would recommend using 18bar (ie 2 bar MORE than we used) for testing of systems if it would do permanent damage to the seals? Pressure testing and observing a length of pipe tells you nothing about what deformations are occurring within the sealed ends where the orings are located. These constraints obviously locally reduce the deformation.
Plastic pipe will increase in size with temperature and reduce to it's original properties when it cools, it actually needs this cooling period or it will be permanently damaged, reducing its life considerably.
See above.
| Quote: | | The test was performed with water, and the technician seemed to be very knowledgeable. *Infinitely* more so than my first, CORGI registered, experienced, dickheaded 'Plumber' who, unfortunately for me, 'did' rather than 'taught' ! |
Being a member of the kennel club is not an guarantee of quality, no more than the safety certificate from Corgi means the system is safe, they have not seen it or done any checks, the certificate is therefor dangerous and misleading.
My point exactly
Talking of knowledgeable technician, the boiler manufacturer say NO, you cannot use leak sealer on their boiler, and yet you are not considering their advice as valid, because Fernox say it's ok.
I have been given conflicting advice from two sources, both of whom should be aware of the consequences of their advice. Whereas you appear to be dismissive of the technical data and advice supplied by Hep20, with nothing to backup your claims. Saying that a procedure recommended by a manufacturer is "stupid and unnecessary" is not usually a wise thing to do.
You have a couple of choices.
Ignore the manufacturer and risk wrecking the boiler.
Finding the leak, maybe with the aid of a dye.
No chance.
Living with what you have and continue to aid fresh water, and topping the inhibitor up once a year.
Probably
Installing an devise that will top it up automatically and checking the inhibitor once a year.
Possibly
john thescruff |
Regards,
Garth. |
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thescruff
Moderator
Joined: 03 May 2003
Posts: 4401
Location: Bath
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| Posted: Wed Mar 12, 2008 6:15 pm Post subject: |
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Fernox are in the business of making money the same as Hep, they have an vested interest in marking up their product.
Where on a roll of hep pipe, do you see an warning that rodents love the stuff, it is now in their literature small print.
Corgi and the HSE say the manufacturers instructions are president, if they say NO then you do so at your risk. One of the major problems with modern boilers is blockage from sludge, the water has to be virtually drinkable, you don't need much imagination to know what leak sealer will do. But hey ho you will probably do what you gotta do anyway 
The idea of testing any pipework is to check for leaks, not to see if it's been assembled by some numpty. |
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Yellowman
Joined: 03 Jan 2008
Posts: 66
Location: Sussex
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| Posted: Wed Mar 12, 2008 6:21 pm Post subject: |
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Garth your coming across as a bit of a tool to be honest.
The Scruff knows his stuff and nitpicking arguments with him isnt gooing to get anywhere.
You come to a plumbing forum for advice and then turn into to the one trying to dish the advice out?
And whats all this about MICRO LEAK. Is it a new term I am yet to hear of, a leak is a leak. |
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