Hydrogen in CH

[jamestovey]

I'm getting hydrogen build up in a radiator on my CH system (when I bleed it it burns strongly, looks like hydrogen from O level chemistry to me). It's only in one radiator but it fills the top 2 or 3 inches of the rad every couple of months.

Any ideas how this is happening, and how to fix it? Otherwise system works fine, and no changes to CH or elec. recently

 

[Stoday]

You need some corrosion inhibitor in your system. Buy some from B&Q

 

[croydoncorgi]

According to which theory you believe, it's either the Schikorr reaction (which mostly only happens at temperatures well above 80C) or bacterial growth.

For reasons way beyond me, most inhibitor 'brand-leaders' do NOT include bactericide and (I strongly suspect) some may even encourage bacteria if there are some present in the system. But you CAN get suitable bactericide as a separate product. Why am I not surprised?

Sorry I have no definite answer for you.

 

[Slugbabydotcom]

A magnetite layer forms on boiler system metal surfaces under normal conditions according to the following overall reaction:

3Fe + 4H2O > Fe3O4 + 4H2

Ferrous hydroxide [Fe(OH)2] is believed to be an intermediate in this process, converting to magnetite above 100°C according to the Schikorr reaction:

3Fe(OH)2 > Fe3O4 + H2 + 2H2O


I'm not really that much of a clever @rse but I did know the first formula though.
I highlighted the bits in red to show where your hydrogen is coming from, basically from the water

I'm going here >
http://www.awt.org/members/publications/analyst/2003/spring/Boiler_Systems_chemical.htm now to swot up on it