Carrier 58MVP Error Code Continuous OFF: No Power

What Does Code Continuous OFF Mean?

A continuous-off LED on the Carrier 58MVP's variable-capacity control board means the board itself is receiving no power. Carrier's guide directs a technician to check for 155 VAC across L1 and L2 and 24 VAC across SEC-1 and SEC-2 — in other words, both the incoming line voltage and the transformer's low-voltage output. With the LED dark the furnace cannot run at all and the thermostat gets no response.

Because the 58MVP is a variable-speed furnace, this control board is the brain that sequences the inducer, hot surface igniter, gas valve, and ECM blower. When it has no power there are no blink codes to read — the dark LED is itself the indication. This is the opposite of a continuous-ON LED, which shows the board has 24 VAC and is in normal standby, and different again from a rapidly flashing LED, which signals reversed line-voltage polarity.

The most common causes are ones a homeowner can safely check: a tripped circuit breaker or blown fuse feeding the furnace, or the furnace's own power switch — which looks like an ordinary light switch mounted on or near the furnace — being switched off, often bumped during cleaning or a filter change. If power is confirmed good at the breaker and switch and the code stays, the problem moves to the transformer or wiring, which is a technician's job.

What You'll Notice

• The control board LED is completely dark, with no blinking at all
• The furnace does not respond to the thermostat and produces no heat
• The thermostat screen may be blank if it draws power from the furnace
• The furnace breaker is in the tripped (middle) position, or the switch near the furnace is off
• The problem began after a power outage, breaker work, or someone servicing the furnace

Common Causes

How to Fix It: Restore Power to the Furnace

What You'll Need

• Flashlight

Steps

1. Turn off power at the breaker and shut off the gas supply valve Before inspecting anything, set the furnace circuit breaker to OFF and turn the gas shutoff valve perpendicular to the pipe (OFF). If you smell gas at any point, leave the home immediately and call your gas company from outside.
2. Check the furnace power switch Find the switch on or near the furnace — it looks like a standard light switch. Make sure it is in the ON position. It is easy to bump off while changing a filter or cleaning around the unit.
3. Check the circuit breaker and any fused disconnect At the electrical panel, locate the furnace breaker. If it is tripped (middle position), switch it fully OFF and then back ON. If there is a fused disconnect near the furnace, check that fuse and replace it if it is blown.
4. Confirm the blower-compartment door is fully seated The 58MVP has a door interlock switch that cuts power if the blower-compartment panel is not properly in place. Make sure the access panel is fully seated so the interlock is closed.
5. Restore power and check the LED Turn the gas valve back ON, then switch the power switch and breaker back ON. The board LED should light. A steady (continuous ON) LED means normal standby and the furnace should respond to a call for heat.

When to Call a Professional

Contact a licensed HVAC technician if:

• The LED stays dark after confirming the breaker, power switch, and access-panel door are all correct
• The breaker trips again immediately after being reset
• There is a burning smell or scorch marks near the furnace wiring or transformer
• The door interlock switch is damaged or does not click when the panel seats

✓ Verified against manufacturer service manual — March 2026