Boiler additives

Old 10-21-07, 06:22 PM
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Boiler additives


I have a question regarding additives for a hot water system with cast iron pipes and radiators.

We have a very reliable electrcal system that rarely goes out. Im not really worried about freezing pipes, as I have a small generator that could run resistance heaters if needed.

However, I am worried about longevity and protection of the pipes, radiators and of course, the boiler. Ive seen additives, like hydronic #5 being sold, with the goal to add a quart once a year and protect your system.

I am curious on the real, true benefits of doing this, what I should look for in an additive (is the stuff sold at home depot OK, or should I look elsewhere?), and what is the best method of adding the additive into the system.

Any insight would be most appreciated.


Old 10-21-07, 06:30 PM
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There really isn't much need for an additive. The best thing for your system is to keep the same water in it as long as possible. The lack of oxygen that comes from repeated heating and cooling with good air venting makes the most inert liquid that you could want for the system. If you drain for any reason, you could add some treatment on refill. Otherwise you have to pump it in. I use 8way and it says on the label you can use it as a cleaner at double strength as long as you drain later and refill. I clean with TSP though and treat with 8way. We almost never clean a boiler unless it is a new installation. Occasionally a steam system will show signs of contamination and we will clean one of them. It takes at least a half day to do it and is labor intensive.


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