BY GEORGE LANTHIER

Although anti-freeze mostly works in the colder weather , it ’ s in the warmer that it gets installed and should be checked . So , let ’ s take a look at pH and how it pertains to heating systems . In looking up pH in an encyclopedia you will find that it is ‘ a measurement of the acidic level and the base of a solution in regards to the activity of hydrogen in the substance or liquid tested .’ In water-based systems , a neutral solution has a pH of approximately seven ( 7 ). Water-based solutions with pH values lower than seven are considered acidic , while pH values higher than seven are considered basic or alkaline . pH is generally considered to stand for ‘ hydrogen power ’, ‘ power of hydrogen ’, or ‘ potential of hydrogen ’ and all of these terms are technically correct . Our pH chart , Figure 1 , was also very popular and yes please feel free to use it , just don ’ t put it in a book you may be writing or we have a problem due to copyrights and such . A lot of people forget this is how I make my living and that chart took quite a bit of time just to have it come out so it looks so good .

To review a few other important things to remember when you are using antifreeze or any boiler or system additive is to make sure that the heater , tank or heat exchanger in use is compatible with those additives . Piping materials , copper , brass , steel , etc . should also be checked for compatibility with the solution to be used and the possibility of electrolysis due to dissimilar materials . Compatibility with certain plastics should also be checked when using plastic piping variations . Make sure that the anti-freeze is an inhibited propylene glycol solution . Make sure that the antifreeze used is specifically made for hydronic heating systems and contains inhibitors for the heating system . Many of today ’ s glycols may be compatible with conventional systems and may not be compatible for use in radiant systems due to the radiant piping material used . Always check first .

Never use glycols that were designed for automotive engines , ethylene glycol , they are toxic and if cross-contamination occurs you could make someone sick or even kill them . Many of today ’ s propylene glycols are specifically made for hydronic systems and are produced differently for the metals seen in boilers , pumps and other system components than for use in the automotive business . You may even have to use a different propylene glycol because your boiler is constructed of aluminum or some other material . So , be careful .

Always check the pH value of the concentration after any system additive installation or during periodic maintenance . On systems containing just water or water-glycol solutions check the incoming water supply pH first to determine your baseline for the water ’ s pH . Then if the pH is different than seven and is not neutral , drain and flush the system and replace the water or antifreeze solution .

Most boiler manufacturers like to see the pH in their boilers , whether hot water or steam , no lower than seven and no higher than eleven , preferring a slightly alkaline solution to an acidic one ( see Figure 1 ). The basic problem is that as the piping , fittings , boiler and everything else ages , the system will actually start to turn the water , additives , and propylene glycol and water solutions to acid . So , it ’ s important that you not only check the pH levels of the solution after installation , but also on a routine basis .

Heating systems that contain propylene glycol should be checked at least once a year to ensure the system pH levels have not dropped below recommended levels . Most glycols are acidic in general to begin with , but through the use of the inhibitors added by the manufacturer are brought back to a more neutral state to help protect the system components . As the system ages , the inhibitors break down , causing the system pH to drop and allow the propylene glycol to return to its acidic state . At this point more inhibitors may be added if allowed by the glycol producer , but all systems reach a point where they will require a complete flush and re-fill . In some systems this could be as little as two years and for many could take as long as five

Figure 1 to seven years , but it all depends on the water and the glycol used . Keep in mind that freeze point and pH are not the same thing , not even close .

Steam boilers can be troublesome after they are installed due to oily materials and foreign agents in the boiler water like cutting oils and pipe dope . As boilers are constructed and piped , oil-based cutting oils are used and can cause surging and priming of the boiler water . These oils can be found in solution on top of the water and will have a different pH than the incoming water . One method to remove these oils is to skim the boiler while maintaining a warm boiler water temperature without steaming . Another method used to clean steam boilers is through the use of trisodium phosphate ( TSP ). TSP is available at most hardware stores in white powder form and is a cleaning agent and degreaser , commonly used to prepare household

32 JULY 2024 | FUEL OIL NEWS | www . fueloilnews . com