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    CHRISX Active Member

    Hello All,

    I would be interested to see Members opinions about a relatively new Heating system water additive.

    Today I saw this product described in an article from the Installer online magazine - previously `The Gas Installer` magazine which was published by CORGI.

    The product is called EndoTherm - here is a link to the online magazine article:

    Five reasons why installers should use energy-saving heating system additives - Installer Online

    The product manufacturer claims that it changes the properties of the Heating system water - making it more thermally efficient / chemically wetter - reducing the surface tension by more than 60% - regarding that the Radiators would heat up more evenly and quicker.

    They claim that the additive will save approximately 15% on the cost of the Gas required to heat a property - which as the product is stated to cost £36.00 [probably plus VAT ?] for a 500ml bottle - `enough for 12 Radiators` would very quickly repay the cost of the additive.

    IF that 15% saving could be readily achieved it would be a `must have additive` - especially as it is stated that it can be added to `dirty water` / existing system water.

    I have heard of this type of `water changing` additive before but I am sceptical about these claims about saving approx. 15% on gas / Fuel Bills.

    I had previously intended to try and find out more about the `Science` regarding `improving heat transfer from heated water via Radiators` AND whether it would be compatible with existing Corrosion Inhibitors - but personal circumstances at that time diverted my attention away and I then forgot about these additives / the claims until Today`s online magazine article.

    I might try to find out more information about this Heating system additive and IF I see plausible details supporting the claims I would think about trying it in my own Home`s heating system.

    However depending on how this Winter`s temperatures compare with last Winters it will probably be difficult to do a cost comparison.

    What do Members think of the Manufacturers `details` / claims ?

    • Optimistic Optimistic x 1
  2. ShaunCorbs

    ShaunCorbs S. Mod Trusted Plumber GSR Top Contributor!!

    snake water (they used to use something like this for car radiators)
    • Like Like x 1

    CHRISX Active Member

    Hello Shaun,

    I am sure that You are correct.

    Having heard about similarly described Heating system additives a couple of years ago what surprises me is that the article / free publicity was selected for inclusion in what I know is a well regarded / relevant online Gas & Heating Industry magazine.

    Although most of the Editorial staff probably don`t have much Technical / Industry knowledge they obviously do have `Technical Advisors` who I would imagine peruse the articles that are selected for publication ?

    As I am sure You were - when CORGI operated the Gas Register I used to be subscribed to `The Gas Installer` magazine which is now `The Installer` online magazine where the article was published.

    I don`t recall reading about many products either in the actual Magazine or the online version where I thought `How could they have published an article about this product ?` - regarding the product details being obviously `dubious`.

    As You might agree - IF this additive was shown to work / saving 15% on Gas / Fuel Bills it would be a `must have` for almost every Heating system !

  4. Chuck

    Chuck Top Contributor!!

    As any real scientist will tell you, extraordinary claims need extraordinary evidence.

    Looking at the claims on the Endothem website:

    "Due to the surface tension of fluid and imperfections in materials inside heating systems optimal thermal contact is not made."

    Surface tension is irrelevant to the thermal contact between the water and the radiator. Even if it did make a difference the water-metal thermal boundary resistance is negligible when compared to the radiator-air heat transfer coefficient of resistance.

    "When dosed EndoTherm stably changes the surface tension of the fluid by over 60% whilst remaining non-corrosive."

    Probably true, but not relevant or remarkable. A drop of detergent will have the same effect.

    "This increases the thermal contact which improves heat transfer rate and efficiency."

    Doubtful. Any efficiency improvement would have to come from improving the condensing efficiency of the boiler as a result of a lower return temperature.

    "Resulting in rooms reaching determined temperature quicker and staying warmer for longer."

    The length of time a room stays warm for depends on the fabric and contents of the room and its losses to the exterior environment. If it's warmer for longer these losses will be increased. The thermal contact between the system water and radiator is still irrelevant.

    "Return water temperature is lower which allows boilers to condensate more efficiently and recover more latent heat."

    The video, which shows a the same radiator ending up two degrees hotter and hence other things being equal having a higher return temperature when the system has Endothern added contradicts this.

    "Less fuel is consumed to maintain thermostatically set temperature."

    This would depend on the boiler performance.

    It is very difficult to measure the in situ efficiency of heating systems correctly with any degree of precision. In my experience, for a domestic property you can easily get +/-30% variations between days with the same average temperature and that's with quite decent controls and a very consistent use by occupiers. So, all someone wanting to formulate such a potion needs to do is set up a reasonably large number of trials and then cherry pick the 50% of results that show an increase in efficiency and ignore the 50% of trials that show a reduction.

    As I would expect, the Energy Saving Trust 'Verification report' that is cited in support of the product claims relies on data supplied by Endotherm and has many caveats.

    In my opinion, one doesn't need to get much more technical than (a) "If it seems too good to be true, it probably is." and (b) "A fool and their money are soon parted."
    • Like Like x 1
    Last edited: Jul 15, 2017
  5. oz-plumber

    oz-plumber Plumber

    The said company must be able to substantiate their claims and have their evidence available to who ever wants to see it.

    I would love to see the scientific evidence if its available.
    And I would like to see the evidence on a 10 or 20 year old system.

    I bet the testing was was done under laboratory conditions.

    A claim of 'approximately 15% savings on gas bills' is a huge claim

    I would love to see the disclaimer
  6. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Never in a million years does that work .
  7. oz-plumber

    oz-plumber Plumber

    Done a bit of research fellas.

    Here's what I found on thinning of water - by up to 60%

    Yes, the compound OH does actually exist. The problem is that an oxygen atom has two electrons in its outer orbitals which require partners to form (covalent) bonds, and live happily ever after. In water - H2O - this has happened, and each electron is matched up with one from a hydrogen atom, so water is good and stable. With OH only one hydrogen atom has come along and joined up with one of the electrons. The other electron is insanely jealous, and will do anything (and I mean anything!) to find a partner. As a result the OH combination doesn't last very long, and it all ends in tears (of water, obviously).

    Molecules with an unpaired electron are known as free radicals. They generally are found as intermediaries in gas phase reactions, with relatively short lifetimes. In chemical equations involving free radicals, the unpaired electron is usually indicated by placing a dot next to the molecular formula eg OH•.

    The hydroxyl ion OH‾ is formed when the second electron completely removes another electron from another atom or molecule, forming a negatively charged molecule or ion, and leaving a positive charge on the other atom. Because they are charged, they cannot exist on a macroscopic scale completely separated from their positively charged partners, called cations, but are stable long-term in solution or in crystalline form. So hydroxyl ions are not compounds, as they do not have independent existence, but they are common components in compounds in which the bonds are ionic.

    The company better not release too much of this product into the oceans or waterways, ships and boats will sink!
    • Funny Funny x 1
    • Informative Informative x 1
  8. SimonG

    SimonG Trusted Plumber Top Contributor!!

    Snake oil. Thermal transfer is thermal transfer.
  9. jtsplumbing

    jtsplumbing Plumber GSR

    Have a look at Fernox products they had one of these out a couple of years back and a lot cheaper than what your looking at
  10. snowhead

    snowhead Well-Known Member

    I bet they weren't making 15% claims.
  11. Chuck

    Chuck Top Contributor!!

    In their current catalogue there's Fernox F2:

    "Fernox Boiler Noise Silencer F2 can be used to reduce the size of steam and air bubbles which form on a heat exchanger. This is achieved by reducing the surface tension of the system water which means only small bubbles are able to form and therefore the associated noise is significantly lessened. However, this product will not solve the underlying causes and therefore a full system clean should be performed at the earliest opportunity."

    The point to note here is that Fermox doesn't claim any benefits due to modification of the heat transfer from radiators just that it mitigates kettling inside the boiler.

    There's also Fernox F6 'Energy Saver', which claims:

    "Energy Saver F6 can save up to 1.2% of energy consumption on a scaled boiler and 0.8% on an un-scaled boiler."

    and, they say improves performance by:

    ". . .laying down long chain molecules within the heating system. This has a dual effect of reducing the size of nucleated boiling bubbles that form on the heat exchanger (which add an additional insulation layer to the heat exchanger surface) and smoothing the internal flow surfaces of the heating system, thereby reducing drag."
    Last edited: Jul 16, 2017
  12. CHRISX

    CHRISX Active Member

    Hello All,

    Thank You very much to the Members who replied to this thread.

    Thanks especially to Members who wrote / posted detailed `Scientific details` relevant to the Manufacturers claims for this product.

    I found all of the information posted by Members very interesting and I am in full agreement with comments made by Chuck and oz-plumber.

    I will not be rushing out to buy a bottle of EndoTherm for my Home`s Heating system.

    Thanks again to all who replied.

  13. GH77

    GH77 GSR

    Too many variables to do an accurate calculation, besides 46.3% of all statistics are made up on the spot :p
  14. zzzjim

    zzzjim Well-Known Member

    So long as it's not by a Pump maker , trying to wash the carbon out of their bearings faster !
    Now extra dirty systems .

    (If it did work the test would be , are my leaks faster like car antifreeze )
    Last edited: Jul 17, 2017
  15. rpm

    rpm Trusted Plumber Top Contributor!!

    Carbon & Bearings ???
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