Why a mechanical clock stops working

Clock repair guide: why mechanical clocks stop working and when to call a specialist

Mechanical clocks have been keeping time for centuries and remain prized for their craftsmanship, precision, and beauty. From antique mantel clocks to traditional longcase clocks, these timepieces often become treasured family heirlooms.

However, many owners eventually experience a common problem: their clock suddenly stops working.

In this guide, we explain why mechanical clocks stop, how to identify the cause, and when professional clock repair is necessary.

---

How mechanical clocks work

Before diagnosing a fault, it helps to understand the basics of how a mechanical clock operates.

Most traditional clocks rely on three main components:

1. Power Source
Mechanical clocks are powered by either weights or a wound mainspring.

2. Gear Train
A system of gears transfers power through the movement to control the hands and striking mechanism.

3. Escapement and Pendulum
The escapement releases energy in small, precise intervals while the pendulum regulates the clock's timing.

When all of these components are functioning correctly, the clock runs smoothly and keeps accurate time.

---

Common reasons mechanical clocks stop

1. Lack of Servicing

One of the most common causes of clock failure is simply lack of regular servicing.

Clock movements contain small pivots and gears that rely on specialist oils. Over time these oils dry out and dust accumulates, increasing friction within the movement.

Most mechanical clocks should be serviced approximately every 5–10 years to maintain proper performance.

2. Worn Internal Components

After many years of operation, parts within the clock movement can become worn.

Common wear points include:

• Pivot holes (bushings)

• Gear teeth

• Arbors

• Springs

When these components wear, the clock may stop intermittently or struggle to keep accurate time. A specialist clock repairer can rebuild worn sections of the movement.

3. Incorrect Setup

Clocks with pendulums—such as longcase and regulator clocks—must be correctly positioned to run properly.

If the clock case is not level, the pendulum beat may become uneven. This often causes the clock to stop shortly after starting.

Even a small adjustment can restore proper operation.

4. Transportation or Moving

Moving a mechanical clock without proper preparation can easily disrupt the mechanism.

Common issues after a move include:

• Pendulum misalignment

• Dislodged suspension springs

• Movement shifting inside the case

Professional setup after relocation is often required to ensure the clock runs correctly.

5. Damaged Mainsprings

Clocks powered by mainsprings rely on tightly wound springs that gradually release energy.

Over time, these springs may weaken, break, or lose tension. When this happens, the clock may stop completely or fail to run for its full winding period.

Replacing a mainspring requires specialist tools and expertise.

6. Environmental Factors

Mechanical clocks are sensitive to their environment.

Factors that can affect performance include:

• Temperature changes

• High humidity

• Dust accumulation

• Direct sunlight

Stable conditions help maintain consistent timekeeping and protect the movement from unnecessary wear.

Signs your clock needs professional repair

While some issues are simple adjustments, others require expert attention.

You should consider professional clock repair if your clock:

• Stops repeatedly

• Loses or gains significant time

• Produces irregular ticking

• Fails to chime or strike correctly

• Has not been serviced for many years

Ignoring these warning signs can lead to further wear and more extensive repairs later.

The importance of professional clock servicing

Professional servicing restores the movement to proper condition and helps preserve the clock for future generations.

A typical clock service may include:

• Complete dismantling of the movement

• Ultrasonic cleaning of components

• Inspection for worn parts

• Re-bushing worn pivot holes

• Polishing pivots and reassembly

• Lubrication using specialist clock oils

• Regulation and testing

When carried out correctly, servicing can significantly extend the life and reliability of the clock.

Preserving antique clocks for future generations

Mechanical clocks represent centuries of craftsmanship and engineering. Whether it is a family heirloom or a valuable antique, proper maintenance ensures it continues running for decades to come.

Regular servicing, careful handling, and professional repair when necessary will keep your clock operating accurately and reliably.