Dear All,
I try to figure out the influence of anti-freeze to boiler treathment chemicals.
Can both be in the system?
Any information, experiences are appreciated.
If your system need protection from freezing, then a good quality hydronic anti freeze should be used. The inhibitor "package" that is added to the base PG antifreeze ( low toxicity propylene glycol) is similar to the boiler treatment inhibitors that are sold as boiler treatment or boiler inhibitors.
Basically the inhibitors in hydronic antifreeze or just plan boiler treatment provide a ph buffer to buffer the fill or blend water you use, oxygen inhibitors to consume any O2 left behind after purge and heat up, a component to lock up any hardness, and film providers which put a very thin coating on the surfaces to help prevent corrosion.
The more expensive antifreeze and conditioners have a more complex "package" some brands may have 30 ingredients. The extra products are to help the product work with a wide array of metals seen in todays systems. Copper, steel, brass, aluminum, stainless steel, etc. The treatment has to work and protect all those metals, over a wide temperature range.
Futhermore with PG glycols the other goal is to keep the final product as a low oral toxicity should some of the fluid get back- flowed into your domestic water system.
If you use either antifreeze or treatment chemicals get a small test kit, or send a sample in every few years. The inhibitors can be consumed and may need a boost added from time to time. If you have an open system, which allows O2 in, then you will need to add or boost more often, probably.
Systems that are piped with non oxygen barrier tube, for example, always allow small amounts of O2 into the systems. This causes the O2 scavanger chemical to get depleted. The indication will be in the ph or test results, and may require periodic boost. Pex tube used for hydronics will often have an EVOH barrier in, or on the tube, just as plastic milk or soda bottles do to prevent O2 ingress.
Over-heating hydronic or solar antifreeze multiple times will also break down the inhibitors. If the ph drops the fluid becomes very aggressive to the less nobel metals. Pin-holes may form in the copper tubing, expansion tanks etc.
If you use either product, flush and clean the system first with a hydronic cleaner or a blend of TSP. I've even used dishwasher soap from time to time, a soap that doesn't foam up when pumped. Flush and fill with good quality water and add the antifreeze or inhibitors and keep an eye on the fluid condition. Just as you do with the motor oil in your car or truck
