28 guides
Parts and tools guides
Each guide explains one part, tool or supply that appears in the manufacturer manuals behind our error-code pages: what it does, which codes name it, how to choose one, how it is tested and when a technician should handle it. Where a guide has shopping links, they are Amazon links and we earn a commission on qualifying purchases; the guides themselves stay the same either way. Affiliate disclosure.
The part finder is the reverse index: a part is listed only when a code's manufacturer document names it, with that sentence and the source on the part page.
Furnaces15 guides · Parts and tools for furnace codes
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.
What a hot surface igniter does, the furnace codes that name it, the resistance range Trane gives, and how to choose a replacement.
What a furnace pressure switch proves, codes that point to it, why you should never jumper it, and how to choose a replacement.
The small hose between the inducer housing and the pressure switch: why it matters, and which codes name it.
What the inducer motor does, the codes that name it, and what to know before buying an inducer assembly.
The furnace circulator blower motor: codes that name it, why airflow comes first, and what to know before buying a replacement.
What a run capacitor does, which furnace and AC codes mention it, the testing method in the Goodman service manual and its discharge warning.
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.
What furnace high limit and flame rollout switches protect, which codes mention them and why we do not link replacements.
How a thermostat fits into furnace and AC codes, how to check compatibility, and where your manual covers the wiring.
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.
How to read the nominal size on a furnace filter, why actual size is smaller, and links for common 1-inch sizes.
What a multimeter measures, which manual steps call for one, how to choose one and the rules for using it safely.
How a non-contact voltage tester works, how to choose a dual-range model and why it never replaces switching power off.
Why nut drivers suit appliance and furnace panels, which sizes a common set covers and what insulated means.
Washing machines9 guides · Parts and tools for washing machine codes
What a multimeter measures, which manual steps call for one, how to choose one and the rules for using it safely.
How a non-contact voltage tester works, how to choose a dual-range model and why it never replaces switching power off.
Why nut drivers suit appliance and furnace panels, which sizes a common set covers and what insulated means.
LG and Samsung say an unlevel washer can cause UE and drain faults. What to use to check and adjust levelling.
How a clogged front-load washer pump filter causes OE, 5C and similar drain faults, what LG and Samsung say to do and what to have on hand.
Drain hose rules from LG, Samsung and Whirlpool: kinks, how far into the standpipe, the U-shaped form and standpipe height.
Hot/cold connections, kinks and inlet filters from Samsung and Whirlpool, and what to know before buying washer supply hoses.
LG tCL is a reminder to run Tub Clean. What LG says to put in the tub, and how washer cleaner tablets are used.
LG Sud, Samsung SUd and Whirlpool Sud all point to detergent. What HE detergent is and how much the manufacturers say to use.
Dishwashers10 guides · Parts and tools for dishwasher codes
What a multimeter measures, which manual steps call for one, how to choose one and the rules for using it safely.
How a non-contact voltage tester works, how to choose a dual-range model and why it never replaces switching power off.
Why nut drivers suit appliance and furnace panels, which sizes a common set covers and what insulated means.
LG and Samsung say an unlevel washer can cause UE and drain faults. What to use to check and adjust levelling.
Bosch E22, E24 and E25, LG OE and Samsung 1E all start with the dishwasher filter. What the manufacturers say and what to use.
Drain hose, air gap and high loop checks from GE, LG, Samsung and Bosch, and what to buy if the hose is damaged.
Bosch E16 to E18, LG IE and GE H2O all start with a kinked inlet hose or closed valve. What to check and what to buy.
Bosch E12 is limescale in the heat pump. What Bosch says and how dishwasher cleaner tablets are used.
Bosch says to use softening salt, if the dishwasher has a water softener, to help prevent E12 limescale.
LG bE and AE point to the wrong detergent. What LG says to use and not use.
AC and heat pumps8 guides · Parts and tools for AC / heat pump codes
What a run capacitor does, which furnace and AC codes mention it, the testing method in the Goodman service manual and its discharge warning.
How a thermostat fits into furnace and AC codes, how to check compatibility, and where your manual covers the wiring.
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.
How to read the nominal size on a furnace filter, why actual size is smaller, and links for common 1-inch sizes.
Why Carrier and Goodman AC codes tell you to check the coils for debris or ice, and the soft-touch supplies for gentle cleaning.
What a multimeter measures, which manual steps call for one, how to choose one and the rules for using it safely.
How a non-contact voltage tester works, how to choose a dual-range model and why it never replaces switching power off.
Why nut drivers suit appliance and furnace panels, which sizes a common set covers and what insulated means.