Thermo Pride CLHS1-050P36N Installation And Operation Manual page 26

All installations and services must be performed by qualified service personnel.
NOTICE: For condensate traps on the Left Side, failure to attach the support bracket or insert the tubing
properly may create a water trap in the tubing, leading to furnace shut-off as a result of a blocked
condensate drain.
4. Attach the second drain hose (a length of 11/16 inch O.D. clear, colorless tubing) from the lower port of the
Flexible Drain Adapter ("A" in Figures 8a & 8b) to the plastic hose barb tee provided in the condensate trap
assembly. Cut to length as necessary and discard excess. Attach the drain hose to the hose barb on the other
side of the condensate trap tee. Use the spring-type hose clamp(s) provided in the parts package to secure
all connections.
5. Plan, source, and install a condensate drain line using ½ inch diameter CPVC (chlorinated polyvinyl
chloride) thermoplastic pipe and pipefittings. In the event ½ inch PVC is preferred, a CPVC to PVC adapter
is included in the parts kit provided with the furnace. Route the line in the shortest possible manner to reach
a nearby drain. Secure all joints using cement. For gravity drainage, the condensate drain line must maintain
a minimum ¼ inch per foot downward slope toward the drain. The drain line must be watertight, supported,
and secured such that it cannot be easily moved.
NOTICE: If an air conditioning condensate drain line is combined with the furnace condensate drain line,
the air conditioning evaporator coil must have a separate trap installed ahead of the connection joint.
6. A condensate pump may be required when,
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a suitable drain is not present,
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the drain is above the trap outlet level on the furnace, or
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the drain line cannot be sloped downward its full length to the drain.
7. CAUTION: Continual exposure to condensate may injure plants and damage certain building
materials, including many metals, wood, stone, and concrete.
Flue gas condensate is slightly acidic with a pH of about 3.5. (A pH level of 7.0 is considered neutral.
Carbonated cola drinks with a pH of 3.1 are actually slightly more acidic than condensate.) If local codes
require an acid neutralizing kit, a kit is available from Thermo Products under part no. 320095. Follow the
instructions enclosed with the neutralizing kit for proper installation.
8. The condensate piping in the furnace and the drain system should be flushed out at the start of every heating
season. This will ensure trouble free operation and will keep the acidity level well above a pH of 3.4, i.e.
more towards neutral.
To flush the condensate drain system, follow these steps.
a. Turn off electrical power to the furnace at the disconnecting switch and adjust the room thermostat to
"OFF", or to the lowest temperature setting.
b. Flush the drain system by removing the drain hose from the Coil Front Cover of the secondary heat
exchanger and running tap water into the open end of the tubing. Run at least a quart of water through
the drain system, until the water leaving the drain system is clear and colorless in color and free of any
particulate matter.
c. Replace the drain tubing by pushing it firmly onto the nipple. Make sure the spring-type hose clamp is
returned to the original position to prevent leaks.
d. If any of the electrical controls are inadvertently wetted during the flushing process, dry them with a
soft cloth and wait 24 hours before operating the furnace.
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