New Boiler Water Question

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bloewendev

New Member
Sep 3, 2025
1
Saskatchewan, Canada
I'm installing a new Portage and Main OWB. The dealer said I should use distilled water to fill but that is both a cost and a hassle since I'm quite a distance away from the nearest city.

My question, is if there is a significant difference in corrosivity between distilled water and the Membrane treated water that I have in my house (source from a well on my property). Naturally I'll be adding the corrosion inhibitor to any water I add.
 
Don't waste your money on distilled water. Add a corrosion inhibitor and send in yearly water samples.
 
The dealer said I should use distilled water to fill
Your dealer is full of it.
Your membrane water with corrosion treatment will do just fine, better than what many people put in!
Our 600k btu "boiler" (gas fired hydronic heater) at work is from 1969 and still runs great...the last time they retubed it in the 80s they were told that the old tubes still looked like new, keep doing whatever you are doing, which is filling with city water (which is hard well water, and not softened much) and treating with Boiler Rite from Damon Products...which they recommend to check chemistry once per year (or after adding new water) basically, just keep the PH between 9 and 10.5, and the nitrites between 1200 and 1500.
No idea what the OWB companies recommend, but its still metal, fire, and water, so I'd bet it is pretty similar levels.
 
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That dealer is nuts. To ease your mind I would check with the manufacturer. Distilled water can be a bad thing since it is void of minerals and might try and take them from your boiler which is why it is considered a corrosive liquid.
 
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Saskatachewan province has some off the most corrosive tap water in Canada ! 250 gallons of distilled water may be very inexpensive in the long run its about $ 150 a gallon at Walmart !
 
Saskatachewan province has some off the most corrosive tap water in Canada ! 250 gallons of distilled water
Distilled water is very corrosive to a boiler/heating/cooling systems too...go with whichever is cheaper, and then treat the heck outta it!