a few pints to them that can cure it !

[Sid Viscous]

Interesting thread! I usually dry test to 3 bar, but I have been known to go to 4 on systems with joints I am suspicious of! Like you say, shut the boiler valves off first!! I use a dry test guage & stirrup pump.

 

[jase158]

yeah as i said before if you go above the safety valve pressure you will never get a true reading as this will open.

Have you put a bottle under the safety valve outlet? just to see if you get anything out?

 

[tiger1050]

Sorry hadnt realised it was on the second page when I posted my last post sorry :6:
Yes its a two storey house but not a large one
Typical running pressure is aprox 0.2 -0.3 above the standing cold pressure.
No I havent put a bag on the relief valve pipe . I will anyway as a matter of course as its a easy job. Bear in mind that the problem has been here for the old boiler as well as this one though.
Air bleed is brand new on the bathroom rad and problem was there before hand
3 Bar was going to be my upper limit as well. However we have seen compressed air piped in copper in the past running at 8 bar on compression fittings !!
Thanks all again and keep them coming

 

[zeebeedee]

They left any dead legs anywhere when converting the system?

 

[Mike Jackson]

Be very wary of testing with air at high pressures, a fitting blowing off under 3 bar of air pressure can do a lot of damage to people as well as property. On no account try to tweak up a fitting if you hear it hissing, drop the pressure first in case it blows off.

 

[Sid Viscous]

Be very wary of testing with air at high pressures, a fitting blowing off under 3 bar of air pressure can do a lot of damage to people as well as property. On no account try to tweak up a fitting if you hear it hissing, drop the pressure first in case it blows off.

High pressure is subjective. Up until 2yrs ago I was installing air con for a living. We would regularly strength test an installation up to 40 bar, (that's around 600psi for you imperial boys) then soundness test to 33 bar with nitrogen. I tell you what, you know about it when a joint lets go at 40 bar!!!
Agree though, don't try & tweak anything under pressure.

 

[geminigas]

Hi All,

4 addative was originally installed but there wont be any in there by now

I would drain, refill and then add an inhibitor, and put in a leak sealer whilst you are at it. This should stop further corrosion whilst will cause gas in the system. I have been using Calchem that is an all in one inhibitor ( it can also be used with calshot leak sealer) although senitel, fernox etc all do their own makes.

 

[tiger1050]

They left any dead legs anywhere when converting the system?

Hi Zeebeedee,
Not that I am aware of. I still think its something related to the original system as the air was there then I just dint need to top it up because of the headed tank.
As soon as the weather warms up and I can take the system down I will go for a air pressuer test
Re putting the inhibiter in and sealer. my concern is I would have spent a fortune on the inhibitor at the rate of the loss/air etc. I still feeel I need to find the cause before I take the sealant as a last option?

Thanks all again

ps if I havent mentioned before then its my guess that I have to put at least a mug full of water in every 3 days . So its got to be a leak........ but its the auto bleed that is masking the air in the system dont forget

 

[kay-jay]

your auto bleed is faulty. its letting air in instead of out.

 

[AWheating]

goto agree with mike regards the air testing, it can be very dangerous. it would be safer to pressure test with water but it can make a mess. If you think about an air riffle that can cause serious injury, normally only 12-14ft lbs of pressure which is nothing compared to a bar of pressure. So a rad valve or pipe fitting poping off at 3-4 bar could cause alot of damage. As with all air testing it should be done with no persons in the property.

 

[DirksPlumbing]

goto agree with mike regards the air testing, it can be very dangerous. it would be safer to pressure test with water but it can make a mess. If you think about an air riffle that can cause serious injury, normally only 12-14ft lbs of pressure which is nothing compared to a bar of pressure. So a rad valve or pipe fitting poping off at 3-4 bar could cause alot of damage. As with all air testing it should be done with no persons in the property.

Very much agreed. Remember 7bar is enough to drive a 4" nail all the way into wood in one go.
The aforementioned 40bar are only manageable at systems with very small bores in _all_ parts of the system including the testing equipment. Do not try anything like that yourself.
And if you feel like air testing at above 1bar make sure you wear ear and eye protection.

 

[DirksPlumbing]

To the OP: my opinion would be H2O - cracking. If you have a metal bleeder you can try to ignite the air at it. But be aware the flame has temperatures around 2000degC. Do not use a lighter. Use a long match. If after ignition it sounds like a small rocket and only stops when you blow it then you know about it. You will most likely not be able to see a flame but it would relight the match again. Looks spectacular. Doing it on plastic bleeders actually too.:devil:

 

[tiger1050]

Wow !
Read my last post and I had'nt noticed how many spelling and grammer mistakes I had made !!! Just tried to edit it but couldnt find the edit button ?
Anyhow replies to the latest questions/advise and thanks again by the way.

As mentioned I have only put the auto air bleeder in the system two weeks ago. The problem has been with me for near 10 years but now getting worse.
I take your points on the testing of the system with air but I will take it up in stages and yup with the PPE. I have done refrigeration in the past also (exam in Bolton with the brazing ,soldering etc) So I get your point on what a mess it can make 🙂
Not sure about the H2o cracking thing you mention. Got any links/info etc ? Thanks

 

[DirksPlumbing]

Just wrote a long answer but this flipping backspace glitch in conjunction with the absence of a possibility to recover the last autosave just made me giving you only a quick one now.

It is an electrochemical reaction which in rare cases as well can get caused by earth faults. Reason number one is flux "contaminated" water.
A givaway is typically raised pressure in the expansion vessel. Otherwise combustion tests as described by AWheating on page 1 or myself proof it.
Water gets split in oxygen and hydrogen. The oxygen typically gets quickly turned over in corrosion. The hydrogen causes airlocks etc.