Water Quality and Mod/Con Boiler

Bill D_3

<span style="font-size:12pt">I am close to purchasing a natural gas Buderus GB142/24 boiler and have a question about Water Quality requirements.  I live in an area with public water and have been told that the water hardness is 10-13 grains.  I am concerned that this will be a problem for the Buderus GB142 boiler as I saw the following water quality requirements in a technical service bulletin:  “Make sure that the water used to fill the system meets the requirements:  Maintain water hardness below 7 grains.”</span>

<span style="font-size:12pt">I then asked two different installers that I was considering and thought were good whether that would be a problem and they both proceeded to say it is not a problem because the water in the boiler is in a closed system and it is “dead water” (as long as there are no leaks).  Neither installer thought that any treatment was necessary.  I want to check with Buderus about this also but would appreciate hearing others’ thoughts about this as well. </span>

<span style="font-size:12pt">Can anyone confirm that they are correct or would it be necessary to get some type of water treatment in order to not damage the boiler and to keep the warranty valid?  If water treatment is necessary what kind of water treatment is used and how costly is it? When the technical bulletin says “Maintain water hardness below 7 grains.” Could that refer to the water in the closed system and not the water filling it?</span>

<span style="font-size:12pt">I noticed that the TriangleTube Prestige Solo also has a similar water quality requirement.  It makes me wonder if I should go back to considering a natural draft/cast iron type boiler that does not seem to be as sensitive as the mod/con boilers.</span>

<span style="font-size:12pt">Thanks for any feedback on this question.</span>

hot_rod

initial fill

water has a lot to do with the performance and life expectancy of the boiler. At the very least then system should be flushed and cleaned. There are numerous products available for this, Rhomar water.com has products blended to be used in multi metal systems. Start with a hydronic cleaner, then add an inhibitor to the final fill fluid.



The final fill water should meet the manufacturers requirement. You can purchase DI or DM (deionized) water from nearby water treatment companies. Haul it to the jobsite in 5 or 55 gallon plastic barrels.



Some installers own DI filters that they haul from job to job to fill hydronic and solar system. Culligan, for one, rents this equipment. It is not the same device as a water softener.



Hard or high TDS water can put a layer of deposits on the inside of the boiler HX surfaces. This reduces the heat transfer ability and could lead to hot spots and premature failures.



It is not an expensive or complicated process to fill a hydronic system with best quality water or fluids. Protect your investment!



If I had a dollar for every failed aluminum boiler HX block that I have seen in suppliers "back rooms" Most failed due to improper fluids being used, be it water or glycol.



hr

lchmb

suggest

I to would  suggest you have the cleaners added to your old system that way all the gunk is flushed back to the old boiler and then removed. The cost to do this is cheap compared to the price of replacing a boiler.  You also want to verify that during your annual service (required on this boiler) that they test the PH level in the boiler. The boiler is very easy to service and generally takes a little over an hour to do it right. Make sure your service man has been through the training on this system.