Water Chemistry

AnthraciteEnergetics

I've seen a lot of steam boilers with rusty water in the gauge glass and gunk in the float low water cutoffs. Mine included for the past 2 seasons I've been running it, discovered my water pH was only in the 6 range.

This year I added just 1 tsp of TSP (teaspoon of trisodium phosphate) to my 3 section / 118k (input) boiler. This brought the water pH up to 9. Gauge glass is now crystal clear and there is no foaming or surging (too high of pH causes foaming - I tried going up to 11, just makes wet steam and causes the radiator vents to tweet like a bird on startup from the violent water level)

This has been mentioned in the past but anyone suffering from rusty boilers and pipes or water surging or foaming issues needs to check water pH! No need for a full water treatment program on these small boilers but a little TSP or baking soda to adjust pH goes a long way! Get it into the 9 range and it will knock down the corrosion rate of your boiler. Check it periodically during the season.

(Be careful with baking soda as it decomposes to sodium carbonate on heating and increases pH further. An 8 or 9 will turn into a 10 or 11 and make the boiler foam. Also generates CO2 so the system needs to be "breathing" to purge that out wheras TSP does not have that problem)

Unfortunately the wet returns are not protected by this type of treatment. You'd need a volatile chemical that leaves the boiler with the steam - excessive for a house system.