During a home inspection I pointed out to my client the different smoke detectors and said it is not wise to mix and match smoke detector ages and brands.
The house is only 12 years old and I found three different detectors in there.
Clearly there are three different smoke detectors here, and of different ages!
The one on the bottom is the FireX brand that is no longer made. That is the one that I had in my house, had to replace, and was the subject of a previous post.
I replaced mine with the recommended brand which you see here in the center photo. Perhaps someone had my same experience.
When I called the manufacturer that had taken over the brand I needed to replace, they said that it is best to replace all of them with the same brand.
They suggested that detectors of the same brand are guaranteed to communicate one with another.
Smoke detectors are a wonderful invention.
When they first came out the detector would usually be placed near the bedrooms. Perhaps only one would be in a house.
Things have changed where they were then placed on every level, and now the codes require that every level and every sleeping area be equipped with one.
AND THE CODE NOW REQUIRES THAT THEY ARE ALL INTERCONNECTED AND CAN COMMUNICATE ONE WITH ANOTHER. THAT WAY, IF THE FIRE IS IN THE BASEMENT THE ONES IN THE BEDROOMS WILL SOUND OFF. AND VICE VERSA.
This is from the National Fire Protection Association:
NFPA 72-2002 C.1 Directly-connected system smoke detectors, commonly referred to as two-wire detectors, should be listed as being electrically and functionally compatible with the control unit and the specific sub-unit or module to which they are connected. If the detectors and the units or modules are not compatible, it is possible that, during an alarm condition, the detector's visible indicator will illuminate, but no change of state to the alarm condition will occur at the control unit. Incompatibility can also prevent proper system operation at extremes of operating voltage, temperature, and other environmental conditions.
Here is why. If you call them, smoke detector manufacturers will always suggest that their products be installed with detectors within their brand, of similar age and with model numbers that are stated to be compatible one with another. What the manufacturers are worried about is that each manufacturer's unit voltage and amperage characteristics are slightly different from the others and as such these differences can cause smoke detectors to falsely report, and/or fail to operate in a timely manner, or draw too much power off the loop and keep other smoke detectors from activating.
My recommendation: if you go to replace a smoke detector, it is probably best to replace all of them. If the replacement detector is pretty similar in age, and is the same brand, it might be appropriate to replace just the one. But if your detectors are older, why not go ahead and replace them all? That way you are sure they are compatible and will communicate with each other. And you are safe.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560