Carrier 58MXA instruction manual ÐGasket on Collector Box, ÐServicing Hot Surface Ignitor

4.Disconnect pressure switch tubes.

→5. Disconnect vent pipe from inducer housing outlet by loosen- ing coupling clamp on inducer outlet.

6.Disconnect drain tube from inducer housing. (See Fig. 8.)

7.Remove inducer housing assembly by removing 4 bolts attaching assembly to cell panel.

8.Flush inside of collector box with water until discharge from condensate trap is clean and runs freely.

NOTE: Ensure the drain tube disconnected from the inducer housing is higher than the collector box opening or water will flow out tube.

9.Inspect inside area of collector box for any pieces of foreign materials and remove if present.

DO NOT use wire brush or other sharp object to inspect or dislodge materials in secondary heat exchangers as failure of the secondary heat exchanger will occur. Flush with water only.

→10. Reassemble inducer assembly by reversing items 5 through 7. Tighten the vent coupling clamp screw(s) to 15 in.-lb. of torque.

NOTE: If seal between the inducer housing and the collector box is damaged in any way, it must be repaired. To repair, apply sealant releasing agent such as PAM cooking spray or equivalent (must not contain corn or canola oil, aromatic or halogenated hydrocarbons or inadequate seal may occur) to inducer housing. (See Fig. 10.) Apply a small bead of G.E. RTV 162, G.E. RTV 6702, or Dow-Corning RTV 738 sealant to groove in collector box.

PAM

RTV

A93081

Fig. 10ÐGasket on Collector Box

11.Refer to furnace wiring diagram and reconnect wires to inducer motor and pressure switch or connectors.

12.Reconnect pressure tubes to pressure switch. See diagram on main furnace door for proper location of tubes. Be sure tubes are not kinked. (See Fig. 8.)

13.Turn on gas and electrical supplies to furnace.

14.Check furnace operation through 2 complete heat operating cycles. Check area below inducer housing, vent pipe, and condensate trap to ensure no condensate leaks occur. If leaks are found, correct the problem.

15.Check for gas leaks.

Never use matches, candles, flame, or other sources of ignition to check for gas leakage. Use a soap-and-water solution. Failure to follow this warning could result in a fire, personal injury, or death.

16. Replace main furnace door.

Step 6ÐServicing Hot Surface Ignitor

The ignitor does NOT require annual inspection. Check ignitor resistance before removal.

1.Turn off gas and electrical supplies to furnace.

2.Remove main furnace door.

3.Disconnect ignitor wire connection.

4.Check ignitor resistance.

a.Using an ohm meter, check resistance across both ignitor leads in connector.

b.Cold reading should be between 45 ohms and 90 ohms.

c.If ohm reading is higher than 110 ohms, ignitor is cracked and must be replaced.

5.Remove ignitor assembly.

Allow ignitor to cool before removal. Normal operation temperatures exceed 2000°F.

a.Do not remove ignitor from bracket while assembly is in furnace. Using a 1/4 in. nutdriver, remove screw securing bracket and ignitor assembly to bottom of burner box. The screw in the bracket is always located toward outside of burner box. The screw may be hidden by inlet box or inlet pipe, but can be removed without removing either. After removing screw, slide ignitor and bracket toward outside of burner box and pull straight out.

The ignitor is fragile. DO NOT allow it to hit the side of the burner box opening while removing or replacing it.

b.Inspect ignitor for a white area indicating a crack may be present. If found, replace ignitor.

NOTE: A small crack cannot be seen on a new ignitor. After a period of operation, a white area will be visible around the crack.

c.If replacement is required, replace ignitor on ignitor bracket external to furnace to avoid damage as the silicon portion is very brittle and will easily crack or shatter.

d.To remove ignitor from ignitor bracket, remove screw holding ignitor ceramic block to bracket and pull ceramic block out of bracket.

6.To replace ignitor/ignitor assembly, reverse items 5a through 5d.

7.Reconnect ignitor wire connection.

8.Turn on gas and electrical supplies to furnace.

9.Verify ignitor operation by initiating control board self-test feature or by cycling thermostat.

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