The Wall Clock Magazine

What to do if my clock is running slow?

Mon Horloge Retarde : 7 Solutions Efficaces pour la Réparer My Clock is Slow: 7 Effective Solutions to Repair It You look at your clock and notice that it constantly shows the time late? Honestly, who hasn't experienced this frustrating situation! As a watchmaker for 15 years, I receive this question daily in my Paris workshop. Honestly, I was puzzled myself the first time my grandmother asked me why her comtoise clock was 10 minutes slow every day. A slow clock can have several causes depending on its type: battery issue for quartz models, balance malfunction for mechanicals, or synchronization failure for radio-controlled ones. The good news? In 90% of cases, you can solve the problem yourself! Summary Identify the type of clock The main causes of delay Repair a quartz clock that is slow Set a mechanical clock Synchronize a radio-controlled clock Preventive maintenance Frequently Asked Questions How to identify the type of your clock? Before you start repairs, you must first determine the type of clock you have. This crucial step will determine the solution to apply. Distinctive signs by type Type of clock Distinctive signs Operation Quartz clock Second hand that "jumps" second by second, visible battery compartment Battery-powered Mechanical clock Visible balance, smooth second hand, manual winding Spring mechanism Radio-controlled clock Mention "DCF" or "radio-controlled", synchronization button Automatic synchronization Comtoise clock Large size, visible pendulum, weights or chains Weight mechanism In my workshop, I notice that customers often confuse mechanical clocks and quartz models. A simple trick: if you hear a regular "tick-tock" and the second hand moves continuously, it's mechanical. If it "jumps" every second, it's quartz! The 5 main causes of clock delay After diagnosing over 2000 faulty clocks, I identified the most common causes of chronic delay: Weak or worn battery (60% of cases for quartz clocks) Balance malfunction (45% of cases for mechanicals) Dust accumulation in the mechanism Ambient temperature too low or unstable Synchronization failure (radio-controlled clocks) Honestly, I was surprised to discover that temperature can affect the accuracy of a clock by several minutes a day! Metals expand and contract, altering the basic settings. Solution 1: Repairing a quartz clock that is slow Battery change: the miracle solution For a quartz clock that is slow, the first check concerns the battery. Even if the clock is still working, a weak battery can cause a gradual delay. Replacement steps: Remove the clock from the wall and turn it over Open the battery compartment (usually with a small screwdriver) Note the type of battery (AA, AAA, or button cell) Replace with a quality alkaline battery Set the clock to the exact time Pro tip that I apply in my workshop: always use alkaline batteries instead of saline batteries. They last 3 times longer and maintain a stable voltage longer. Checking the quartz mechanism If changing the battery does not solve the problem, the quartz mechanism may be faulty. In this case, replacing the entire movement is necessary (expect to pay 15-30€ for a standard movement). Solution 2: Adjusting a mechanical clock that is slow Balance adjustment: the expert technique For a mechanical clock that is slow, the adjustment is made via the balance. This is where it gets technical, but I will explain it simply. Locate the adjustment screw or the balance nut (usually marked "F" for Fast and "S" for Slow). Here’s the method I teach my apprentices: To speed up the clock: turn towards "F" (Fast) in quarter turns To slow it down: turn towards "S" (Slow) Test 24h before adjusting again Lens adjustment (pendulums) On comtoise clocks and other pendulums, the pendulum lens is adjusted differently: Action Effect on the clock Recommended adjustment Raise the lens Speeds up the clock 2-3 turns for 1 min/day Lower the lens Slows down the clock 2-3 turns for 1 min/day Frankly, who would have thought that a simple adjustment of a few millimeters could correct a delay of several minutes? That's the beauty of mechanical watchmaking! Solution 3: Synchronize a radio-controlled clock Manual synchronization procedure Radio-controlled clocks receive a time signal from the DCF77 station in Germany. Sometimes, this signal is disrupted or the clock loses synchronization. Re-synchronization method: Hold the synchronization button for 3-5 seconds Place the clock near a window (better reception) Avoid disruptive electronic devices Allow synchronization to occur (5-15 minutes) In my experience, 80% of radio synchronization issues are related to an inadequate location. Keep your clock away from televisions, computers, and other sources of interference. Preventive maintenance: avoid breakdowns Maintenance schedule by type Good preventive maintenance avoids 70% of delay issues. Here is my professional schedule adapted for the general public: Quartz clocks: annual battery change, semi-annual cleaning Mechanical clocks: servicing every 3-5 years, regular winding Radio clocks: monthly synchronization check Antique clocks: professional oiling every 2 years Basic cleaning and maintenance Regular cleaning of the mechanism is crucial to maintain accuracy. Use a soft brush to remove dust from visible gears, but avoid chemicals that could damage the lubricants. Honestly, I've seen too many clocks damaged by attempts to clean with WD-40! For delicate mechanisms, consult a professional watchmaker. When to call a professional watchmaker? Some cases require the expertise of a qualified watchmaker. Do not attempt the repair yourself if: The delay exceeds 30 minutes per day The clock stops regularly You hear abnormal noises This is a valuable antique clock Basic adjustments do not improve the situation In my workshop, I usually charge between 40 and 80€ for a complete adjustment, depending on the complexity of the mechanism. It's an investment that extends the life of your clock by several years! Frequently Asked Questions Why does my clock run slower in winter? The temperature variations affect the metals in the mechanism. Cold contracts the parts, slightly slowing the movement. This is normal for mechanical clocks, less so for quartz which are more stable. How much does it cost to repair a slow clock? The cost varies depending on the type: battery replacement (5-10€), mechanical adjustment (40-80€), full service (100-200€). Antique clocks may require a larger budget. Can I repair a mechanical clock myself? The basic pendulum adjustments are accessible to DIY enthusiasts. However, avoid disassembling the mechanism without experience. A mistake can turn a 50€ repair into a 300€ restoration! My quartz clock is slow despite a new battery, what should I do? If the problem persists after changing the battery, the quartz movement is likely faulty. Replacing the entire movement costs 15-30€ and is easy to do. How often should a radio-controlled clock be synchronized? The automatic synchronization usually occurs every night. A monthly manual synchronization is enough to check proper functioning, except in cases of moving or disturbances. How do I know if my grandfather clock needs servicing? Watch for these signs: a delay of more than 5 minutes per day, irregular pendulum swing, abnormal noises, or frequent stops. A professional service every 3-5 years maintains performance. In conclusion, a clock that is slow is not a fatality! With the right techniques and a bit of patience, you can regain perfect accuracy. Don't hesitate to consult a professional for complex cases – your clock will thank you!