Reference library
How it works
One mechanism per page. Each explainer has an original diagram, names the parts (and links them to the glossary), describes how the thing fails, and draws the line between a homeowner's repair and a licensed professional's. Every fact is footnoted to a source we read.
Plumbing
Plumbing
How a pressure-balance shower valve works
Why the shower does not scald when the toilet flushes
HVAC
HVAC
How a gas furnace cycles
Eight steps between the thermostat clicking and warm air at the register
HVAC
How a central air conditioner and a heat pump move heat
Nothing is made cold. Heat is moved from where you are to where you are not.
HVAC
How a furnace and AC filter works
The cheapest part in the system, and the one behind most of its problems
Electrical
Electrical
How a GFCI trips
The outlet that counts electrons in and out, and cuts the power when they do not match
Electrical
How a circuit breaker trips, and what an AFCI adds
Two trip mechanisms in one switch, and a third that listens for sparks
Electrical
How power gets into and around a house
From the transformer on the pole to the outlet behind the couch
Carpentry
Carpentry
How wood moves with the seasons
Why the drawer sticks in August and the floor gaps in January
Carpentry
How a wall is framed
Plates, studs, headers and the question of what is holding up the floor above
Carpentry
How a door hangs, and why it sticks
Hinges, jambs, the strike plate, and the gap that has to stay open all year