Garage doors in New York. We quote the part that broke.

A blinking opener light during a failed close is the opener telling you its safety sensors are unhappy. The two photo eyes sit about six inches off the floor on either side of the opening, and they have to see each other. Something has usually knocked one out of line, or a cobweb, a leaf or low sun is breaking the beam. Look for a steady light on each eye. That is a free fix in most cases, and we will talk you through it on the phone rather than charge you to come out and do it.

Look at the spring on the shaft above the door. A broken torsion spring shows a clear gap in the coil where the two halves have separated, usually an inch or two. The second sign is weight: pull the emergency release and try to lift the door by hand. With a good spring it comes up easily. With a broken one it feels like it is bolted to the floor. If you see the gap, stop using the opener, because the motor is not built to lift the door on its own and will strip its gear trying.

Yes, and we will if that is what you want. What we will also tell you is that the other spring has been through the same number of cycles and is the same age, so it is usually close behind. A new spring working against a tired one pulls unevenly and the door shows it. We price it both ways and let you decide rather than deciding for you.

Usually not. A single damaged section can be replaced, as long as the manufacturer still makes that door in that style and the colour is close enough to live with. We check both before quoting. Where a door is discontinued, or several sections are damaged, or the whole assembly has been racked out of square, a new door genuinely is the better buy and we will show you the comparison rather than just asserting it.

Springs are rated in cycles, not years, and one cycle is one trip up and one trip down. A builder-grade torsion spring is typically rated around 10,000 cycles. A household that opens the door twice a day gets many more years out of that than one that opens it eight times a day, which is why two identical doors on the same street fail years apart. High-cycle springs are wound from heavier wire and rated for considerably more.

Both safety reversal tests, a hand balance test with the opener disconnected, a check of the springs, cables, rollers, hinges and bearings, tightening of the hardware that vibration has worked loose, alignment of the safety sensors, adjustment of the travel and force settings, and proper lubrication of the moving parts. You are told what we found, including the parts that are fine.

No. WD-40 is a solvent and a water displacer rather than a grease, so spraying it into rollers and hinges strips out the lubricant that was already there and leaves them drier than before. Use a lubricant sold for garage doors, on the rollers, hinges, bearings and the spring coils. It costs a few dollars at any hardware store and it is the cheapest thing you can do for the door.