You are here:

Antique Clocks/Fast running Seth Thomas mantle clock


I have a Seth Thomas mantle clock that constantly runs fast, about 2-3 minutes per hour. I have adjusted the speed adjustment screw in the counter-clockwise so much that I'm afraid the screw will back all the way out. (The other direction speeds it up). There is no adjustment on the pendulum bob itself. Do you have any suggestions? Thanks.

Check to see that when you turn the adjustment screw on the front with a key that it actually moves the pendulum spring down to make it longer.  Sometimes the screw is stripped and it does no good to turn the screw on the front.  If the adjusting system is still operating properly you may have to purchase a pendulum that is adjustable or you can trim a little off of the pendulum rod and rebend the hook where it attaches to the pendulum itself.  Let me know what you find out.

Please visit our web site:

Antique Clocks

All Answers

Answers by Expert:

Ask Experts




I will answer any clock repair questions to the best of my ability but not appraisal questions.


I have been repairing mechanical and electric clocks for over 25 years.

I am a current expert in the small appliance catagory.

BS Education

Past/Present Clients
We have been in business in the Madison, Wi. area for over 30 years.

©2017 All rights reserved.