How Bad Is the School’s Heating System Water?
Your school on acid.
The school had the heating water tested in November. The report gives the data, but no explanation of what the results mean. The report lists the Account Manager. I called him to ask him to explain the results. He said he could not, that I’d have to speak with a technician, and that he would have a technician return my call. Because my call was not returned, I’ve turned to the internet to provide interpretations of the results.
The water is really bad. It is causing severe damage to the metals in the system.
pH = 5.5. That’s acidic. The pH should be 8.3 to 10.5. Figures below 8.0 can be increased by adding corrosion inhibitor, but below 7.0 indicates the glycol has oxidized and must be replaced.
Reserve Alklinity = 0.4. It should be 10 to 12. This is about the level of the buffering agent and metal passivators that are included in the inhibited glycol formulation. The buffering agent functions to buffer the acids as they are formed by the break-down of the glycol.
Sodium Nitrite = 0. Sodium nitrite is a steel corrosion inhibitor. Levels should vary from a low of 500 ppm to a high of 1500 ppm.
Iron = 327,000 ppb. It should be below 20. (Note figures have been converted from mg/L to ppb.) The water is full of iron because it is eating away at the iron pipes.
Copper = 7,400 ppb. It should be below 15. Same problem as with the iron.
Phosphate levels = 0. It should be 30 – 50 PPM in order for the complete reaction of the phosphates with the calcium hardness entering the boiler through the feedwater.
The suspended matter test is positive. The water is dirty because it is full of dissolved parts of the heating system.
The water was last replaced in the summer of 2023.
The test results:
Good to know it may not need replacement. There should still be a root cause analysis to determine where the breakdown on maintenance occured to prevent future problems.
Obviously this is going to require a lot of money to fix. Probably a complete replacement. That said, it is absolutely critical to find out how the current problem came about. Without that knowledge, there is risk for this to happen again. This means tracing back to when problems first occurred or potentially showed up in maintenance reports. To start, ask all service vendors to provide records going back as far as possible, and analyze from there.