Counteracting Corrosion in Hot Water Heating Systems

HeatingHelp.com

We have all seen the effects of corrosion at some point, right?

From pipes and fittings to major components, corrosion is part of a natural process and will occur in every system where any type of metal is present, and once a new system is installed, the clock to counteracting corrosion begins ticking!

Hands up if you have had callouts for boiler leaks, ECMs that have failed or heat exchangers that are cracked? Corrosion can dramatically reduce the efficiency of a system, and even cause boiler failures. Magnetite, or black iron oxide is a result of oxidation inside an untreated hydronic system and is one of the main causes of heating system breakdowns.

Corrosion can never be completely stopped, but it can be prevented from occurring in a new system and slowed down in an existing system via three simple steps: Test. Clean. Protect.

Test - Testing is a vital step in understanding the quality of the water in the system.

Clean - Any system with corrosion occurring will need a clean.

Protect - The process of corrosion never stops, which is why any hydronic system will need the long-lasting, continuous protection of a magnetic filter.

To learn more about counteracting corrosion, click HERE.

And always remember - Test. Clean. Protect. Every install. Every repair. Every service!



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Dave Carpentier

I always wondered why dont we have sacrificial anodes in heating systems (like in a water heater, boat motors etc)

Larry Weingarten

Hi, I'm right on the edge of what I know here, but I think it has to do with the amount of oxygen in the system. In theory, if iron saw no oxygen, it couldn't rust. Galvanic corrosion may not care if oxygen is present, as it just needs an electrolyte that's conductive.

An interesting test would be to put iron and copper, bonded together in an oxygen-free conductive fluid and see what happens. Will the iron just sit there and smile, or will it dissolve away?


Yours, Larry

mattmia2

Larry Weingarten said:

An interesting test would be to put iron and copper, bonded together in an oxygen-free conductive fluid and see what happens. Will the iron just sit there and smile, or will it dissolve away?

That is what you do in a closed hydronic system, you have steel and iron components and fittings and you connect them to copper piping and as long as there isn't oxygen getting in to the system from fresh water being added to replace water added from a leak or non oxygen barrier plastic components are used, it for the most part doesn't.

hot_rod

Test, test, test is the key. Test the water before it goes in, fix it if needed. Check the fluid after a weeks run, then occasionally through the years.

It is almost impossible to keep 100% of the O2 out. Pump seals, gaskets, perhaps even press fittings o-rings? leak some O2.

A research piece at the CDA site claims even new copper connected to old copper can set up a small galvanic cell. So dissimilar metals certainly can and do.

I believe the hydronic conditioners help a lot with O2 scavenging, film providers, etc. They too want good quality water blend with them.

Derheatmeister

MikeAmann said:

I added powered titanium anodes to both my boiler and stainless steel IWH.

MikeAmann said:

I added powered titanium anodes to both my boiler and stainless steel IWH.

Are you operating with chemicals or without chemicals in your heating system ?

Derheatmeister

What is your PH and EC ?

jumper

Both for steam and hot water there are methods to minimize O2 & CO2.
Not used too often on closed systems.

Derheatmeister

MikeAmann said:

@Derheatmeister
What is your PH and EC ?
You mean me? I never tested. I just want the protection without anything disolving into the tanks.

Yes...Sorry, I should have Quoted your post
How did you install the Titanium Anode in your heating system ? Is it installed in a "reaction vessel" ?
EC stands for Electrical Conductivity which is measured in micro siemens.
In order to keep the different materials from reacting towards each other (Galvanic action) we try to keep it low.
In Germany in a "Chemical Free" system such as you are trying to maintain we try to keep the EC below 100 micro siemens . We also try to maintain the PH between 8.2 to 8.4 unless you have a Aluminium HX.
However,In order to keep any warranty in place always follow the Manufacturers system fluid recommendations.

IMO there are two ways you can handle "Counteracting Corrosion in Hot Water Heating Systems"

1. Try to become a chemist and throw a bunch of Chemicals towards it which is not so great for our enviroment !
2. Approch it without chemicals by using Deionized water and Sacrificial Anodes .

If you have a constant buildup of Magnetite that is just a indication of issue that has been left unaddressed..Most installers will start by using a "Magnectic filter" which is not getting to the root of the cause.

If you want to know more regarding this subject you can read the VDI 2035, The new ANSI H1001.1 Standard or you can Email me directly.
Sorry for the Germenglish ..Richard.

Derheatmeister

MikeAmann said:

Here is the one I have installed on my SS IWH. You just remove the aluminum rod that the unit came with and install the powered unit, connect the circuit, and plug it in.

I got mine here: https://www.ebay.com/itm/142271777319?hash=item21200f0a27:g:0dMAAOSwZgtiN63S

Can you please post Pictures on the location of the Heating system Anode?

PC7060

MikeAmann said:

I just put it in the unused rear tapping, which is right at the bottom of the tank. This boiler is old, but when I removed the plug that was there, all the threads looked brand new. I took a look inside the tank and was blown away with what I saw - great shape. So I installed the powered titanium anode because I want to keep it that way.  

Nice labeling.  Always good to leave a clue for the next guy.  That remind me I need to add a few labels to my system.