Affiliate links may earn us a commission. As an Amazon Associate I earn from qualifying purchases. Affiliate disclosure
15 guides
Parts and tools for furnace error codes
These are the parts, tools and supplies that the manufacturer manuals behind our furnace code pages name. Each guide explains what the item does, how to choose and test it and when to leave it to a technician. Shopping links are Amazon links; search links open results and never confirm a fit for your model.
By brand
Amana furnaceAmerican Standard furnaceBryant furnaceCarrier furnaceGoodman furnaceLennox furnaceRheem furnaceTrane furnaceYork furnace
Guides
Furnace flame sensor
What a furnace flame sensor does, which codes point to it, how manuals say to clean it, how to choose a replacement and how a technician tests it.
Furnace hot surface igniter
What a hot surface igniter does, the furnace codes that name it, the resistance range Trane gives, and how to choose a replacement.
Furnace pressure switch
What a furnace pressure switch proves, codes that point to it, why you should never jumper it, and how to choose a replacement.
Furnace pressure switch hose
The small hose between the inducer housing and the pressure switch: why it matters, and which codes name it.
Furnace inducer (draft) motor
What the inducer motor does, the codes that name it, and what to know before buying an inducer assembly.
Furnace blower (circulator) motor
The furnace circulator blower motor: codes that name it, why airflow comes first, and what to know before buying a replacement.
As an Amazon Associate I earn from qualifying purchases.
Run capacitor (furnace blower and AC)
What a run capacitor does, which furnace and AC codes mention it, the testing method in the Goodman service manual and its discharge warning.
Furnace control board and low-voltage fuse
What an integrated furnace control board does, the codes that name it, why a blown fuse comes first, and how to buy a board safely.
High limit and rollout switches
What furnace high limit and flame rollout switches protect, which codes mention them and why we do not link replacements.
Thermostat
How a thermostat fits into furnace and AC codes, how to check compatibility, and where your manual covers the wiring.
Furnace and AC air filter
How a dirty filter triggers furnace and AC codes, how often to change it, how to read the size and what the MERV rating means.
Furnace filter sizes: how to read and match yours
How to read the nominal size on a furnace filter, why actual size is smaller, and links for common 1-inch sizes.
As an Amazon Associate I earn from qualifying purchases.
Multimeter for appliance and HVAC diagnosis
What a multimeter measures, which manual steps call for one, how to choose one and the rules for using it safely.
Non-contact voltage tester
How a non-contact voltage tester works, how to choose a dual-range model and why it never replaces switching power off.
Nut driver set
Why nut drivers suit appliance and furnace panels, which sizes a common set covers and what insulated means.
As an Amazon Associate I earn from qualifying purchases. Affiliate disclosure