Extension Spring Replacement: what to note first

The door climbs with the left corner ahead of the right, then twists as it turns into the ceiling track. Looking up, the spring on the right side is stretched longer than its partner, with daylight showing between the coils.

Worth answering before the call

Has insulation, glass or a wood facing been added to the door? Do the springs run along the tracks beside the door, or is there one spring above the opening? Is a car parked inside that will need to come out first?

Will the lift cables be changed as well?

They are inspected every time and changed when they show fraying, rust at the bottom loop, or a kink from having jumped a pulley. Cables and springs are generally the same age, and with the door already open and the springs off, fitting new cables adds little to the visit. Bright, tight strands with clean loops can stay and are simply re-routed over the pulleys and set to the new springs.

What does the paint colour on the end of the spring mean?

Manufacturers dab a colour on the end coil to indicate the spring's weight rating, which is a handy starting point. It is not the final word: a faded or repainted end coil tells you little, and the pair on an older door may have been a near match rather than the right one. The technician treats the colour as a hint and confirms the rating from the door's measured weight and the spring's own dimensions.