Smoke detectors can fail.  In a commercial or restaurant application, with the amount of dust, grease and other pollutants not common in a residential environment, your smoke detector needs to be changed or serviced more frequently.

Finding the right detector can be troublesome and expensive.  Most fire alarm companies will charge a pretty penny to make a service call.  The key thing to remember is that you can change your own detector as long as you match like kinds.  What that means is that your fire alarm system, duct detector or heat detector are rated as part of the overall fire protection system in your building.

You need to be sure to replace your failed or old detector with the exact kind, or else you might need to upgrade your complete fire alarm system.