Theo Marlow

A thermostat not working is one of the few household faults where the part you are standing in front of is usually innocent. The screen is blank, or it is lit and nothing happens when you push the temperature up, and the natural conclusion is that the thermostat died. Far more often it is fine … Read more

You push the handle and nothing useful happens. Before you reach for the plunger, understand that a toilet won’t flush for three separate reasons, and the plunger addresses only one of them. A handle that swings loose while the bowl water sits still is a fault inside the tank. A bowl that fills high and … Read more

A heat pump frozen under a sheet of white frost on a January morning is almost always doing exactly what it was built to do. In heating mode the outdoor coil has to sit colder than the outdoor air, because that is how it pulls heat out, and moisture in that air freezes on the … Read more

A smoke detector chirping once every half minute or so is not the fire alarm going off, and it is not always asking for a new battery. One short chirp on a repeating cycle is a maintenance signal, and the single most useful thing to know about it is this: if the chirp carries on … Read more

The shower goes cold and nothing you turn brings it back. When you have no hot water, the most useful move is deciding which of two unrelated problems you have, because nearly every troubleshooting list blends them. A tank that delivers nothing hot is failing at ignition or at power. A tank that gives you … Read more

Water beading on the inside of your glass on a cold morning is window condensation, and in almost every case it reports on the air in the room rather than a defect in the window. Glass is the coldest surface in a heated house, so indoor moisture lands there first. A pane fogging on the … Read more

Low water pressure in house plumbing is two different problems wearing the same symptom, and one question separates them: is it one fixture or every fixture? Before you buy a showerhead or a cartridge, open a second faucet on another floor, then an outdoor hose bib. If only the first fixture is weak, the restriction … Read more

Water is coming through the ceiling and you are in the hallway trying to remember where the valve is. Working out how to shut off water to house plumbing takes five minutes on a dry afternoon, and the next failure then stops in thirty seconds instead of ten. The step almost everybody skips is the … Read more

Furnace short cycling is the pattern where the burners light, run for seconds or a few minutes, shut off, then start again long before the house reaches the temperature you set. The cheapest correction is also the most useful one. Pull the air filter out and hold it up to a light. Restricted airflow sits … Read more

A dryer not heating at all is a different fault from a dryer that heats fine and still needs three cycles to dry a load of towels. The first means the heat source is switched off, and the fix is rarely a part inside the cabinet: it is the electrical supply on an electric machine … Read more