North Star 157117 Owner's Manual page 41

Maintenance & Repair
SCALE BUILD-UP/EXPLOSION HAZARD
• Failure to properly maintain the coil can result in a steam explosion.
• Scale or lime build-up will act as an insulator and decrease coil efficiency.
• Weakening of the coil tube due to hot spots can result in a coil rupture.
CHEMICAL EXPOSURE HAZARD
• Always wear properly rated safety goggles when descaling the coil.
• Always wear rubber gloves when handling coil cleaning chemical.
• Understand all safety hazards and first aid measures for coil cleaning
chemical being used.
• Follow coil cleaning chemical manufacturer's directions when handling,
mixing and using coil cleaning chemical.
Read owner's manual. See maintenance section of manual for descaling procedure.
Read the coil cleaning chemical safety information.
Serious injury or death can result if safety instructions are not followed.
To descale the coil:
1) Remove the outlet coil quick connect nipple fitting from the coil outlet.
2) Remove the inlet coil swivel fitting from the coil inlet.
3) Connect hose(s) as shown below to the coil inlet, coil outlet and the circulating
pump. Do not hook up the pressure washer hose or gun.
4) Add commercial coil cleaner to water and mix. Use an acid resistant 5-gallon
bucket.
5) Place the remaining end of the Return Hose into the 5-gallon bucket.
6) Place the remaining end of the Supply Hose B into the 5-gallon bucket. We
recommend using an inlet filter screen on Supply Hose B.
7) Connect the power supply to the circulating pump.
8) Turn on the circulating pump to begin circulating the coil cleaning solution.
9) Run the circulating pump for 1 to 3 hours (follow coil cleaner manufacturing
instructions), recirculating the coil cleaning solution. CAUTION: Do not run
the pressure washer or the burner.
WARNING
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