I just spent the good part of a day talking to Google and our local fire department. I live just outside of Boston, MA, USA. We recently started building an extra bedroom in an older house. In order to get the building permit approved, we had to insure all living spaces comply to the new fire code, not the code that was there at the time of installation of existing units; which appears to be similar to what is in Europe. This ended up adding an additional 6 detectors that we had to install in the house. The only missing link for us to continue using the Nest Protect system was the heat detector requirement for the garage. The only way we were able to solve it was to hard wire the heat detector to the nearest smoke/CO detector so that they are interconnected. No company makes a wireless connected heat detector (to my knowledge) that connects to Nest and Google, as you have read, do not produce a compliant product. Being its an older house and we had no options to run interconnected wires through the walls. The best and only solution we found was as follows:
- AC hardwired smoke/CO detectors in all required spaces (for the power source with battery backup)
- Interconnected wireless throughout the house
- Heat detector hard wire connected to AC and the nearest smoke/CO detector from the garage to the nearest unit in the house (mudroom)
The only system out there, that I have found that can accomplish this is the Kidde P4010ACSCO-W (for the smoke/CO detector), the Kidde AC135F (heat detector), and you can also use P4010ACS-W (smoke detector only no CO detection). The third item which does not include the CO detection is typically used in bedrooms whereas the smoke/CO combos are used in open spaces, hallways etc...
It is really unfortunate. I just bought 12 Nest Protect units that I will returning tomorrow. I even asked the fire department if there is any other option to use the Nest product and a standalone heat detector, the answer was a resounding no. The heat detector must be hard wired and interconnected (through a wire) to at least one smoke or smoke/co detector that is interlinked with others.
The final option I explored was just simply installing an additional Nest protect in the garage being that it has a heat sensor/detector built in. The problem here is that with the amount of dust, CO and other debris generally found in the garage, it will most likely keep being triggered. This happened when I had the mudroom door open where we have a current Nest detector installed and after cutting just 2 pieces of wood on my saw, the fire alarm went off.
Hope this helps some people with older houses. It's taken me almost 2 months of diligent searching to try and find a solution here. I really love the Nest products but if they can't work, they just can't. It's that simple. Google is the key but if they do not want to solve it, we have no choice. The one feature I will definitely miss is the location of possible dangers which is broadcast through the speaker. With all retrofit units that run on a wireless interconnected network, you will lose that functionality. The only way to have that functionality in some of the newer apps from Kidde and others is if the entire house is hard wired with 14/3 wire at the time of construction.