Carrier 59MN7B Installation, Start-Up, Operating And Service And Maintenance Instructions page 88

CAUTION
!
UNIT COMPONENT DAMAGE HAZARD
Failure to follow this caution may result in damage to the
furnace and other property damage.
Do not use ethylene glycol (automotive antifreeze coolant or
equivalent). Failure of plastic components may occur.
1. Obtain propylene glycol (RV/swimming pool antifreeze or
equivalent).
2. Turn off gas and electrical supplies to your furnace.
3. Remove furnace control door.
4. Remove the top unused rubber plug from the port on the
collector box opposite the condensate trap. See Fig. 58.
5. Connect a field supplied 3/8- -in. (9.5- -mm) ID tube to the
open port on the collector box
6. Insert a field supplied funnel into the tube.
7. Pour 1 quart of anti- -freeze solution into the funnel/tube.
Antifreeze should run through the inducer housing, overfill
condensate trap and flow to an open drain.
8. Replace the rubber plug in the port on the collector box.
9. Remove the middle unused rubber plug from the port on
the collector box opposite the condensate trap. See Fig. 58.
10. Repeat Steps 5 through 8.
11. If a condensate pump is used, check with pump
manufacturer to verify pump is safe for use with antifreeze
used. Allow pump to start and pump anti- -freeze to open
drain.
12. Replace main door.
13. When furnace is re- -started, flush condensate pump with
clear water to check for proper operation before re- -starting
furnace.
14. Propylene glycol need not be removed before re- -starting
furnace.
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