How do you fix Goodman E5?

This is technician work. Finding a short in low voltage wiring means tracing the circuit, and doing that safely means knowing which parts of the board are still live. Do not simply fit a larger fuse. The rating is chosen to protect the transformer and the board, and a bigger one lets the fault damage components that cost far more than the fuse. Full steps and safety notes are on this page.

Goodman furnace E5: Low voltage fuse is open

E5 means the fuse protecting the 24 volt control circuit has blown. The fuse is a symptom — something shorted the low voltage wiring, and replacing the fuse without finding it just blows the next one.

Do the simple checks below, then stop. The simple checks listed above are genuinely homeowner work and worth doing first. Beyond them, this fault involves the gas valve, the burner compartment, or the heat exchanger — the parts whose failure can put combustion products, including carbon monoxide, into the air the house breathes. If the simple checks do not resolve it, stop there and call a licensed technician rather than resetting the furnace repeatedly to keep the heat on. Make sure there is a working carbon monoxide alarm on every level of the home, including the level the furnace is on. The conditions that mean stop now.

Applies to: Goodman GMVC96, GMVM97, GCVC96, GCVM97 and Amana AMVC96, AMVM97 series gas furnaces with a two-character alphanumeric display.

What it means

The control board carries a small fuse, typically three or five amps, protecting the 24 volt circuit that runs the thermostat, the gas valve, and the safety switches. It blows when that circuit is shorted, and the furnace stops completely because nothing on the low voltage side can operate. The important thing to understand is what a blown fuse actually tells you: fuses do not fail with age the way filters clog. It blew because current went somewhere it should not have, and the short is still there. This is why the fault frequently recurs immediately after a fuse change made without investigation.

Most common causes

A short in the thermostat wiring — the single most common cause, often where the cable passes through a wall or a sharp metal edge.
A thermostat wire pinched by a panel or shorted against the cabinet.
Damaged wiring at an outdoor unit, where the same 24 volt circuit often runs.
A shorted or failing gas valve, transformer, or other 24 volt component.
Rodent damage to low voltage wiring.
A wiring mistake made during a thermostat replacement, particularly involving the common wire.
Water reaching a low voltage connection.

How to diagnose it

Note when the fault started. Immediately after a thermostat change, a new smart thermostat installation, or work at the outdoor unit points straight at the wiring that was disturbed.
Check whether the thermostat display is blank. A furnace-powered thermostat going dark alongside this code confirms the low voltage side is dead.
Look for obvious wiring damage where cable is visible and reachable, without dismantling anything.
Note whether a previously replaced fuse blew again quickly. That is diagnostic in itself and worth telling the technician.

How to fix it

This is technician work. Finding a short in low voltage wiring means tracing the circuit, and doing that safely means knowing which parts of the board are still live.
Do not simply fit a larger fuse. The rating is chosen to protect the transformer and the board, and a bigger one lets the fault damage components that cost far more than the fuse.
Have the short found rather than the fuse replaced. A technician who only changes the fuse has not finished the job.
If a thermostat was recently installed, mention it. Miswiring during a smart thermostat installation is a leading cause and is quickly checked.

Notes

This code makes a furnace look completely dead while the actual fault is a few pounds' worth of fuse and a damaged wire. It is also one where the temptation to fit whatever fuse is in the drawer causes real damage — the rating exists to protect the transformer.

All codes for this manufacturer

Goodman and Amana furnace fault codes — every code, with what differs between models.

Models this code appears on

From the manufacturer's per-model database. If your model is not listed, this code may not exist on your board, or it may mean something different — check the model page.

The same fault on other control families

The blown low-voltage fuse has cousins everywhere, differing mainly in honesty of presentation: Carrier 24 names the secondary voltage fuse outright, Trane E12 reports an open fuse, and two Goodman-family boards fold the fuse into shared codes — five red flashes on the GMEC96 and six flashes on the GMSS9 both pair it with a rollout trip. E5's virtue is saying exactly what opened. The control board cost guide covers the other presentation entirely: a popped fuse with no code at all, impersonating a dead board.

What the fix costs

The board guide prices this fault's whole span at $5–150 — a dollar for the automotive-style fuse, the rest for the part that matters, which is finding the short that blew it. That search has famous endings: a staple through a thermostat wire, a low-voltage lead pinched under a panel screw, a chafed wire at the furnace knockout, or damage from a thermostat swap done live. What the fault should not cost is a control board. E5 means the fuse did its job and the board survived; a $400–900 board quote for a fuse code deserves the question 'what killed the fuse, and why does that condemn the board?' before anyone signs it.

DIY or call a pro?

The fuse is visible and cheap, which makes this the most tempting false DIY in the code list — and the page's own warning explains the trap: the fuse is a symptom, and a new one feeding the same short blows on arrival or, worse, holds long enough to cook wiring. Finding a low-voltage short means isolating circuits at the terminal strip, which is meter work. The genuinely useful homeowner move is reconstructing the timeline: E5 right after a thermostat replacement, a nursery-camera install, or any wire-adjacent project practically names the suspect, and handing that history over converts an open-ended hunt into a ten-minute confirmation.

What this looks like

From the outside, this usually shows up as the furnace is completely dead — that walkthrough covers what to check in order, and when it stops being a homeowner job.

This can also show up as the furnace not turning on at all — that page is a 5-minute checklist before calling anyone.

Sources

Goodman Manufacturing — Diagnostic Code Identification System (model-specific fault code lookup)

This site is a reference, not a substitute for a licensed HVAC technician. Gas appliances can leak carbon monoxide and cause fire. Anything involving gas lines, the heat exchanger, or the flame sensing circuit should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.