This might be 2 questions so I can separate it into two if needed.

I want to put a CO detector in two places of my home (kitchen and garage). However, the instructions that came with the CO detector said not to put it in there.

In the kitchen, I have a gas stove. I also want to put one in the garage because of the hot water heater.

I was reading the instructions for the CO detector. It said not to put one in either of these rooms. It doesn't state any exceptions (water heater/gas stove) so I don't know if it saying not to install it in these rooms is with or without the presence of these appliances.

Should I install detectors in these rooms or not?