URGENT - Hyrdrogn in NEW Central Heat Systm.

universe · 12 Jan 2004

URGENT, if you are able to suggest a solution to me.
Many thanks.
Archie

BACKGROUND:Reputable central heating installer.
Complete new central heating system, boiler/pipes/radiators
Combination condensing gas boiler, sealed system.
Standard Copper pipes (25mm).
Radiator thermostat valves.
The whole system recently installed totally new.

PROBLEM:
There is a steady, continuous, build up of hydrogen gas in the system, which results in a steady rise in system pressure as shown by the boiler gauge (about 0.1 bar every 2 days).

What is causing this steady, persistent build up of hydrogen gas in this completely new system?!!

NOTES:
The sound of small gas bubbles is clearly heard in ONLY ONE radiator valve (noise stops when this valve is closed), however, the gas build up still continues.

System has been drained three times so far, also 2 times inhibitor strength in the system.

Out of frustration, I am about to ask the installers to take the whole system down!

After 3 times draining the system over 2 months, FLUX cannot be causing this problem!

Is one radiator valve causing this due to oil leakage of some sort (I am just guessing).

Is this caused by the boiler? - what could be leaking from it into the system, or, what is corroding?

Based on your experience, what is the most likely cause of this problem?

DP · 12 Jan 2004

Have you tested the gas and found it to be hydrogen?

universe · 12 Jan 2004

DP -
The first time the engineer investigated the gas build up, the gas from a radiator burnt strongly -> ie hydrogen.
Unless you believe, there might have been TWO problems (hydrogen + air), but how can air get into system if it is pressurised (combi boiler sealed system)?

ADDITIONAL NOTE:
The boiler water inlet valve (ie the fresh water inlet to the boiler) was CHANGED, just in case it was letting in fresh water from the mains into the system.

sterose · 12 Jan 2004

universe said:
DP -
The first time the engineer investigated the gas build up, the gas from a radiator burnt strongly -> ie hydrogen.
Unless you believe, there might have been TWO problems (hydrogen + air), but how can air get into system if it is pressurised (combi boiler sealed system)?

ADDITIONAL NOTE:
The boiler water inlet valve (ie the fresh water inlet to the boiler) was CHANGED, just in case it was letting in fresh water from the mains into the system.

If find it laughable that you have come to the conclusion that it is hydrogen because it burns..

It is not altogther impossible (at least in theory) that Hydrogen is being produced, but nevertheless unlikely...

Perhaps you should consider that it is possibly another gas besides Hydrogen.

Are you sure you didn't connect the Gas pipe to the Rads....[laugh]

But seriously, I would look close at the boiler, as besides corrosion, this is the only place where anything remotely like a chemical reaction could happen.

universe · 12 Jan 2004

OK Sterose . . . now you got me worried.

There's no noticeble smell of 'natural gas' when bleeding radiators.
The water extracted is clear but fizzy/foam/froth, water clears after a few seconds.

Is it possible that boiler heat exchanger or something else is reacting even though there's 2 times concentration of inhibitor in system (X100 Sentinel).

Please give me more detail on potential NEW boiler complications.

BOILER:
Glow-wom 30CXi, combi condensing boiler (sealed system).

System pressure (boiler guage) returns to initial lower value, after letting gas out of radiators - this is 'almost' reproducible.

oilman · 12 Jan 2004

Speak to Sentinael's technical department, they will know almost everything about the corrosion problem you have, and far more than any of us. Do it today, and get a sample of the water out of the system, and a reference sample from your cold tap, and send it to them for analysis (if they offer the service). It will be chargeable.

You should really get the installer to do this, as you would expect the system to be ok when installed. It's a real pain for the installer, so be as pleasant as possible about it. It may be something to do with copper swarf in the system, and this is not good, as it makes holes in things.

If Sentinel don't do it, Fernox do.

sterose · 12 Jan 2004

universe said:
OK Sterose . . . now you got me worried.

There's no noticeble smell of 'natural gas' when bleeding radiators.
The water extracted is clear but fizzy/foam/froth, water clears after a few seconds.

Is it possible that boiler heat exchanger or something else is reacting even though there's 2 times concentration of inhibitor in system (X100 Sentinel).

Please give me more detail on potential NEW boiler complications.

BOILER:
Glow-wom 30CXi, combi condensing boiler (sealed system).

System pressure (boiler guage) returns to initial lower value, after letting gas out of radiators - this is 'almost' reproducible.

You might find that the super-concentrated water is actually a problem.
I've never used inhibitor, but is it flammable?
It could be that the excess is boiling or something and releasing flammable gas.

And when you say the gas burns, do you mean a little tiny flame, or a burst of flame from the radiator.

Basically, try elimination of components. Try isolating problem radiators. Remove unneccessary components.

My guess is still that it's the boiler though. If it is Hydrogen, there must be some sort of electrolysis going on somewhere. That or some sort of acid reaction.

DP · 12 Jan 2004

Hydrogen is lighter than air. It can be collected in an upturned tumbler held above the vent from which the gas is being released. A lit taper when introduced into upturned glass will result in popping sound when gas ignites.

You best bet is to send system water for analysis. Aluminium heat exchanger reacting with chemicals (I wonder). There was a time when one had to use special chemicals if aluminium rads were fitted to a system for corrosion protection.

sterose · 13 Jan 2004

DP said:
Hydrogen is lighter than air. It can be collected in an upturned tumbler held above the vent from which the gas is being released. A lit taper when introduced into upturned glass will result in popping sound when gas ignites.

You best bet is to send system water for analysis. Aluminium heat exchanger reacting with chemicals (I wonder). There was a time when one had to use special chemicals if aluminium rads were fitted to a system for corrosion protection.

I suggest a long....long, long...taper is used to light the collected gas.

In any case have you tried bleeding all the gas out of the radiator. And then see if it fills up (or fills up, less).

universe · 13 Jan 2004

Sterose - a steady continuous build of gas is the problem - ie approx 0.1 bar every 2 days - this seems to remain the same.

Example: Last week I de-gassed the radiators (extracting tiny amounts of fizzy water as usual) press went down to 1.1 bar - Today the press reads 2.4 bar! So if I do the same today, the press will likey go back down to 1.1, and with gas/time it will rise again.

After the system was drained last time, there's no 'noticable/significant' change in the 'slow rise' of gas in the system.

The gas is heard through pipes occasionally, as well as accumulating in radiators (2-3 out of 8 radiators) - so I think whatever the cause, it must be either in the water as a whole, the pipes or the boiler, ie not just confined to radiators (my conclusion only). It's puzzled the heck out of me!
and it's a worry . . .

Gas from radiator burnt like a pressuried lighter flame first time (only time) we investigated the gas - ie opposite of a slow candle flame - it's a pressurised system anyway at about 2.3 bar.

Cheers

oilman · 13 Jan 2004

and it's a worry . . .

Have you phoned Sentinel then?

What did they say?

universe · 13 Jan 2004

Oilman - thanks for your message. Things go wrong in clusters . . .
So was unable to phone them yesterday/today - but yesterday I emailed Sentinel & Glow-worm, no reply yet, tomorrow I'll phone both parties plus british gas heating.

The majority seem to think improper system flushing (I have my doubts on this now) - a close second propose boiler (mechanical air intake or heatxchngr).

I'm watching this forum like a hawk for experience/insight/suggestions.

I'll update you asap.

oilman · 13 Jan 2004

The majority ........

This is not a matter for debate, as you know you need some facts, so until you have gathered them from suitable sources (erm...Sentinel) all these other guesses are not helping. I could see from the start this will be a job for a chemist to clear the gas problem first, then you might be able to look at something else, but until then, you may as well save your energy.

Dave_A · 15 Jan 2004

HI
Hydrogen is a possibility due to electrolytic action. The cause may be debris in the system, instead of changing the water (compounding the situation) flush it using a propriety flushing agent (sentinel or fernox) then use the correct amount of corrosion inhibitor.

Hope that helps

ps. I am a Heating Engineer

universe · 15 Jan 2004

Water sample has been taken, awaiting results.
Hydrogen build up continues.

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URGENT - Hyrdrogn in NEW Central Heat Systm.

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