How do you fix Goodman P1?

Nothing to fix. This is normal dual fuel operation. If the system never switches to the furnace in cold weather, have the switchover configuration checked. Full steps and safety notes are on this page.

Goodman furnace P1: Low stage compressor, heating mode

P1 means the heat pump is heating the house on its low stage, and the furnace is idle. On a dual fuel system this is the cheaper heat source doing the work.

Applies to: Goodman GMVC96, GMVM97, GCVC96, GCVM97 and Amana AMVC96, AMVM97 series gas furnaces with a two-character alphanumeric display, installed as part of a dual fuel system with a heat pump.

What it means

In a dual fuel system the heat pump handles heating in milder conditions because it is cheaper to run, and the gas furnace takes over when it gets cold enough that the heat pump becomes inefficient. P1 means the heat pump is running on low stage and the furnace is standing by. Seeing this while the house is warm is confirmation the system is doing what it was designed to do — using the less expensive heat source. It is worth documenting because a homeowner checking the furnace display during heating and seeing a compressor code can reasonably wonder whether something is wired wrongly.

Most common causes

The heat pump is providing heat on low stage. This is normal dual fuel operation in mild conditions.
Outdoor conditions above the switchover point where the heat pump is more economical.
The system correctly selecting the cheaper heat source.

How to diagnose it

Confirm the system is dual fuel. If there is no heat pump, this code should not appear.
Note the outdoor temperature. Heat pump operation in mild conditions is correct.
Note whether the system switches to the furnace when it gets colder, which confirms switchover is working.
If the heat pump runs in very cold weather while the house does not keep up, the switchover point may be set wrong.

How to fix it

Nothing to fix. This is normal dual fuel operation.
If the system never switches to the furnace in cold weather, have the switchover configuration checked.
If the furnace runs when the heat pump should be handling mild conditions, that is also worth checking — it costs more to run.
Do not use emergency heat as a default setting. It bypasses the heat pump entirely and runs the expensive source.

Notes

The switchover point on a dual fuel system is a real setting with real cost consequences. Set too high, the furnace runs when the heat pump could have; set too low, the heat pump struggles in conditions where it is inefficient.

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.

What the fix costs

Nothing to repair — P1 is the cheapest heat source in the system carrying the load, which is the point of dual fuel. The cost content here is mostly about calls avoided: low-stage heat pump air feels mild at the registers, and 'lukewarm vents' with P1 showing and the house holding temperature is normal operation, not a $75–150 diagnostic waiting to happen (repair cost guide). Where money is legitimately involved: a system that sits in P1, never steps to P2 or hands over to gas, and loses the house — staging and changeover diagnosis, technician work billed from the same diagnostic base.

DIY or call a pro?

Watch the sequence rather than the single code: P1 in mild weather, P2 as it cools, gas heat in real cold is the healthy pattern, and observing it costs nothing. Filters and registers are yours. Everything else is professional — staging logic, changeover temperature, refrigerant charge — because all of it needs instruments or configuration access. One caution: do not force the system to emergency or auxiliary heat as a workaround for cool-feeling air; it works, the house warms, and the bill quietly becomes the most expensive version of itself.

What this looks like

From the outside, this usually shows up as there is no heat but nothing looks obviously wrong — that walkthrough covers what to check in order, and when it stops being a homeowner job.

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.