Carrier 58MEC instruction manual Service

SERVICE

If status code recall is needed, briefly remove then reconnect one main limit wire to display last stored status code. Repeat remove-and-reconnect four more times for previous four status codes, after which the five codes repeat. Status code 11 will display when less than four previous status codes exist. On RED LED controls do not remove power or blower door before initiating status code recall.

LED CODE STATUS

CONTINUOUS OFF - Check for 115VAC at L1 & L2, & 24VAC at SEC-1 & SEC-2. CONTINUOUS ON - Control has 24VAC power.

RAPID FLASHING - Line voltage (115VAC) polarity reversed. If twinned, refer to twinning kit instructions.

EACH OF THE FOLLOWING STATUS CODES IS A TWO DIGIT NUMBER WITH THE FIRST DIGIT DETERMINED BY THE NUMBER OF SHORT FLASHES AND THE SECOND DIGIT BY THE NUMBER OF LONG FLASHES.

11	NO PREVIOUS CODE - Stored status codes are erased automatically after 72
	hours. On RED LED boards stored status codes can also be erased when
12	power (115 VAC or 24 VAC) to control is interrupted.
	BLOWER ON AFTER POWER UP (115 VAC or 24 VAC) -Blower runs for the
	selected blower off-delay time, if unit is powered up during a call for heat
13	(R-W/W1 closed) or (R-W/W1) opens during blower on-delay.
	LIMIT CIRCUIT LOCKOUT - Lockout occurs if a limit or flame rollout switch is
	open longer than 3 minutes. - Control will auto reset after three hours.
14		- Refer to #33.
	IGNITION LOCKOUT - Control will auto-reset after three hours. Refer to #34.
21	GAS HEATING LOCKOUT - Control will NOT auto reset.
22	Check for: - Mis-wired gas valve		- Defective control (valve relay)
	ABNORMAL FLAME-PROVING SIGNAL - Flame is proved while gas valve
	is de-energized. Inducer will run until fault is cleared. Check for:
23	- Leaky gas valve		- Stuck-open gas valve
	PRESSURE SWITCH DID NOT OPEN Check for:
24	- Obstructed pressure tubing		- Pressure switch stuck closed
	SECONDARY VOLTAGE FUSE IS OPEN Check for:
31	- Short circuit in secondary voltage (24VAC) wiring.
	HIGH-HEAT PRESSURE SWITCH OR RELAY DID NOT CLOSE OR
	REOPENED
32	Control relay may be defective, refer to status code #32
	LOW-HEAT PRESSURE SWITCH DID NOT CLOSE OR REOPENED - If
	open longer than five minutes, inducer shuts off for 15 minutes before retry. If
	opens during blower on-delay period, blower will come on for the selected
	blower off-delay. Check for: - Excessive wind			- Restricted vent
	- Defective inducer motor		- Low inlet gas pressure (if LGPS used)
	- Defective pressure switch		- Low inducer voltage (115 VAC)
	- Inadequate combustion air supply		- Proper vent sizing
33	- Disconnected or obstructed pressure tubing
	LIMIT CIRCUIT FAULT - Indicates a limit or flame rollout, switch is open.
	Blower will run for 4 minutes or until open switch remakes whichever is longer.
	If open longer than 3 minutes, code changes to lockout #13. If open less than
	3 minutes status code #33 continues to flash until blower shuts off. Flame rollout
	switch requires manual reset. Check for: - Dirty filter or restricted duct system
	- Proper vent sizing - Restricted vent		- Loose blower wheel		- Excessive wind
	- Defective blower motor or capacitor		- Defective switch or connections
34	- Inadequate combustion air supply (Flame Roll-out Switch open).
	IGNITION PROVING FAILURE - Control will try three more times before lock
	out #14 occurs. If flame signal lost during blower on-delay period, blower will
	come on for the selected blower off-delay. Check for:
	- Oxide buildup on flame sensor (clean with fine steel wool)
	- Proper flame sense microamps (.5 microamps D.C. min., 4.0 - 6.0 nominal)
	- Manual valve shut-off			- Control ground continuity
	- Gas valve defective or gas valve turned off			- Low inlet gas pressure
	- Inadequate flame carryover or rough ignition			- Defective Hot Surface Ignitor
	- Flame sensor must not be grounded
43	- Green/Yellow wire MUST be connected to furnace sheet metal
	LOW-HEAT PRESSURE SWITCH OPEN WHILE HIGH-HEAT PRESSURE
	SWITCH IS CLOSED - Check for: - Disconnected or obstructed pressure tubing
	- Mis-wired pressure switches		- Low-heat pressure switch stuck open
45	- Low inlet gas pressure (if LGPS used)
	CONTROL CIRCUITRY LOCKOUT		Auto-reset after one hour lockout due to;
	- Gas valve relay stuck open	- Flame sense circuit failure
	- Software check error				repeats.
	Reset power to clear lockout. Replace control if status code

COMPONENT TEST

To initiate the component test sequence, shut OFF the room thermostat or disconnect the "R" thermostat lead. Briefly short the TEST/TWIN terminal to the "Com 24V" terminal. Status LED will flash last status code and then turn ON the

inducer motor. The inducer motor will start in HIGH speed and remain on HIGH speed until the end of the test then shift to LOW speed for 7 to 15 seconds. The hot

surface ignitor, blower motor LO HEAT speed, blower motor HI HEAT speed, and
blower motor COOL speed will be turned ON for 10-15 seconds each. Gas Valve
and Humidifier will not be turned on. When the blower is turned OFF the inducer will
be switched to low-speed for 10 seconds.	327885-101 REV. B

Fig. 21 - Service Label

58MEC

A02258

15