If your school, hospital, or commercial building has Simplex synchronized wall clocks, you know the frustration when they stop working. These iconic clocks — found in hallways, classrooms, and waiting rooms across America — are tied to a master clock system that keeps every clock in the building synchronized.
When a Simplex clock fails, finding a replacement that works with your existing system can be surprisingly difficult. Here’s what you need to know.
Why Simplex Clocks Are Hard to Find
Simplex (now Johnson Controls) has shifted focus to digital systems. Many of the analog synchronized clock models have been discontinued, which means:
- Johnson Controls no longer manufactures many legacy clock models
- Most fire alarm distributors don’t stock clocks at all
- You can’t just put up any clock — it needs to work with your Simplex master clock system
Simplex Clock Models We Stock
Life Safety Consultants is one of the few suppliers that still carries Simplex replacement clocks:
Round Wall Clocks (6310 Series)
- 12″ round single-dial — the standard classroom and hallway clock
- 12″ round double-dial — visible from both sides, ideal for corridors
- Battery and AC-powered options
Square Wall Clocks (2310 Series)
- 12″ square synchronized — common in hospitals and modern commercial buildings
- Surface mount — clean, professional appearance
Digital Clocks (6334 Series)
- LED digital displays — for areas requiring high visibility
- Various sizes and colors
How to Choose the Right Replacement
- Check the model number on the back of your existing clock (usually starts with 6310, 2310, or 6334)
- Note the size — 12″ is the most common, but other sizes exist
- Confirm your power source — AC (120V) or battery-operated
- Check if it’s single or double-dial (can you see it from both sides?)
If your clock model isn’t listed in our store, contact us with the model number — we can often source discontinued models or recommend compatible replacements.
Shop Simplex clocks: Simplex Replacement Clocks →
