Vent Condensation - A.O. Smith Cyclone Xi Service Handbook

VENT CONDENSATION

Failure to properly install the drain line on the
condensate elbow will result in a water heater shut
down and a "blocked exhaust" fault message.
The average dew point of natural gas flue products is
127 ° F. Propane flue products is 119° F. With 70° F
ambient air temperature and 180° F stored water
temperature, exhaust gas will be approximately 140°
F.
Q. CAN I DRAIN THIS CONDENSATION TO THE
FLOOR DRAIN?
A. The "Corrosion Resistance of Cast Iron Soil Pipe"
by the Ductile Metals Association (formally the Cast
Iron Soil Pipe Institute) states that:
"Internal corrosion of cast iron soil pipe and fittings
can be caused by strong acids or other reagents
having an acidity of pH 4.3 or less if allowed to contact
cast iron pipe for an extended period of time without
sufficient dilution to raise the pH valve about 4.3. By
avoiding low pH discharges, internal corrosion
problems can be limited or eliminated, assuring the
owner many years of service."
Q. WHAT ABOUT THE Ph VALUES OF
CONDENSATE AND SODA POP?
A. The pH of the BTH condensate average 4.5 which
is approximately 4 times less concentrated than the
limit of 4.3 recommended by the DMA. Any water flow
in the drain rapidly dilutes the condensate even more.
A can of leading carbonated cola drink measured a pH
of 2.5 which is 300 times more concentrated than the
A.O. Smith – Technical Training Department
CYCLONE Xi COMMERCIAL GAS WATER HEATER
BTH 120 thru 500 SERVICE HANDBOOK
Servicing should only be performed by a Qualified Service Agent
BTH condensate.
Q. WHAT DOES THE Ph SCALE MEAN?
A. The PH value is a measure of acidity or alkalinity. A
pH of 7 is neutral. Numbers from 7 to 1 indicate
increasing acidity and numbers from 7 to 14 indicate
increasing alkalinity. The pH scale is similar to the
Richter scale used to measure earthquakes. Each
number indicates a change of 10 times the
concentration of the previous value. A pH-6 is 10
times more concentrated than a pH-7, a pH-5 is
(10x10) 100 times pH-7 and pH-4 is (10x10x10) 1,000
times pH-7, etc.
Q.WHAT ABOUT CONDENSATE NEUTRALIZERS?
A. Condensate neutralizers are usually not
necessary. A condensate neutralizer is easy to make
by filling a short length of 2" or 3" PVC pipe with
landscape marble chips, capping it and installing it in
series with the condensate drain of the equipment.
Most commercial neutralizers are off the market
because of poor demand for the product.
Condensation from the exhaust vent piping and tank
internal flue way must be allowed to drain. A "blocked
flue" indication will often be your first indication that
condensate is not draining.
12 Ashland City, Tennessee © 2009
316586-000