Weil-McLain C-1013 Troubleshooting Manual page 14

Discolored water from the hot water faucet (Non-Warranty)
The water from the hot water faucet appears discolored, either rusty, brown,
black or yellow. Because the inner tank is stainless steel, which by its nature is
resistant to corrosion, the problem is not tank related. The problem is usually a
non-toxic iron reducing bacteria that is commonly found in soil, well water,
water treatment plants and piping systems. The bacteria usually thrives in those
systems in which the soluble iron exceeds 0.2 ppm. The bacteria will feed on the
soluble iron in the water producing "rusty" color water as a by-product of the
feeding process.
Variables in which the bacteria can thrive in:
• Elevated levels of iron and manganese in the water
• Water with little or no dissolved oxygen
• Water storage temperatures below 140ºF
Items that can potentially increase the presence of the bacteria:
• Water softeners
• Well water
• Long periods of no water movement
Action Item:
- The treatment of this situation requires the water system to be shockchlorinated.
Depending on the severity of the bacteria within the water system, several treatments may
be needed.
Check the ph and the Chlorides of the water in both the inner (domestic) tank
and the outer (boiler) tank. Ph must be between 6 and 8. The chloride must be
less than 80mg/l. Note the ph and Chloride readings on the RGA Paperwork.
Items that can affect the ph reading:
1) Water Softeners
2) Water treatment plants
a) Cl ( Chlorides) added, especially during the summer
b) Fl ( Fluorides) added in treatment in large cities
3) Elevated levels of iron, manganese, and sulfur
If the ph is out of range it has a big effect on the metal tanks, piping and heat
transfer surfaces.
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