testing for unknown inhibitor

[Worcester]

The two most common branded products, Sentinel and Fernox, offer simple test kits for their own products, they claim that they are different chemicals, so their test kits are specific to their product. Additionally not all our clients us the 'retail' brands.

As we work on many different systems (sometimes with large volumes e.g 1500 litre buffer tanks) we are looking for a generic testing kit that can tell us the % concentration of inhibitor. - Simply saying 'not enough' isn't adequate.

Why %?

On the larger volumes, the recommended dosage is half the normal, so we need to know how much to add, not just shove in 7 litres @ £100 per litre of Fernox superconcentrated....

 

[Ric2013]

I would also like to know the answer.

 

[Last Plumber]

yep, gone are the days of a 6" nail in a half filled jar eh ?

I tried to find the answer to this one a few years ago. I didn't get very far !

Only a suggestion but have you thought of ringing a chemists lab. They may know the answer or point you in the right direction.
The type that test water, like the labs you take water samples when testing for legionella might know.
If you do find a kit or an answer, let us know.

 

[Ric2013]

The nail in a jar did occur to me. It used to be a standard Fernox test!

 

[Worcester]

Ok, Got a really good answer from the guys at Kamco that offer a multi use full test kit at a reasonable price.

(The answer is nothing available --- yet !!)

Thanks for your e-mail in which you ask if our inhibitor level test kit will work with any inhibitor, including those from Sentinel and Fernox, and I will try and clarify matters.

A Systemsafe DM Concentrate test kit will only give the correct answer when used on a system containing Systemsafe DM Concentrate.

The test checks the level of molybdate in the treated water.
When Systemsafe is dosed at the ideal rate (impossible to guarantee in a real system of unknown volume of course), this optimum level is 100 parts per million of sodium molybdate.

Other inhibitors may not use as much molybdate, and may substitute other materials (most do, as molybdate is expensive.)

There are many different formulations, and most good and proven inhibitors will be a blend of up to a dozen components.
Other inhibitors are often very basic, and very dilute - but they wouldn't pass the Buildcert inhibitor standard as Systemsafe DM Concentrate does.

Whilst annual checking of inhibitor level is an excellent idea, doing this presents a problem to all inhibitor manufacturers – what make of inhibitor is IN the system? Currently there is no test kit that will test for all inhibitors, and if the brand of inhibitor in a system is unknown, the only safe thing is to drain down and start again.

As at summer 2016, Kamco and other inhibitor manufacturers (including Fernox and Sentinel) have been in discussions with the HHIC (the boiler manufacturers trade association) to develop a test that would work with any inhibitor whose manufacturer joined the scheme. This test procedure is at a relatively early stage, and would mean measuring the alkalinity of the water treated with inhibitor, and comparing it against a known value for that particular manufacturer’s inhibitor, i.e. you still would need to know what brand of inhibitor was in the system.

Kamco, and our better competitors, are keen that the sticker supplied with the inhibitor is left attached to the system / boiler so that the installer / engineer has a chance of knowing what inhibitor is in the system - and when it was added.

I understand why you wouldn’t want to drain systems down and start again, (sorry!) but at least in future there is hope to improve the situation – although you still really need to know what inhibitor is in the system.

and they even pre-empted my next questions

PS I think you will have another question to ask, so:

It's unlikely that mixing two inhibitors will do any harm.
However, most inhibitors are NOT all the same, as many people think.
They are complex blends chosen for the abilities of individual components, although it is probable that some elements will be common, even if not in the same quantities.

But you, and we, will never know exactly what is in competitor products - our competitors are rather coy about giving us details of their formulations.
There's a good chance that upon mixing both inhibitors will provide some degree of protection, but the ideal situation would be to drain down and only use one inhibitor in your system.
It is not only prudent to use an inhibitor to keep a system clean and long lasting, but Part L of the Building regulations states that an inhibitor must be added to heating systems to comply.

Only challenge is that with 5000 litre buffers and district heating system, draining down isn't practical!

 

[michael c]

What's the nail in the jar test?

 

[Worcester]

What's the nail in the jar test?

What it says on the tin!

Get a clean bright nail (not galved or coated) take a sample of water from the system in a jar, put the nail in the jar, put the lid on and leave it for 2 days, see if it goes rusty.

Some people use wire wool as it has a larger surface areas.

To be really true there should be no air in the jar - it should be completely full, else the air can get absorbed and the nail should be fully submerged.

 

[EPH]

I use this Primelab.

 

[PETE 123]

Show off

 

[Ric2013]

As promised.

R