Carbon monoxide has no smell and no color, which is why a working alarm matters in a house with a gas furnace, a gas water heater, a gas range, or a fuel-burning space heater. The alarm is a safety device, not a substitute for ventilation, service on the appliances, or a call to a professional when something seems wrong. Install it with the same care you would give a smoke alarm, and treat the manual as the authority on where it goes.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Before you buy
Look at the house first. Check which fuel-burning appliances are present and where they sit. Decide which type fits: a plug-in unit with battery backup, a battery-only unit, or a hardwired unit that connects to other alarms in the house. Hardwired units are wiring work and belong to a licensed electrician unless you have the training and the permit to do the job yourself. Check the box and the manual for placement rules before you buy. Do not buy a used unit, and check the end-of-life marking printed on the back of the unit before you accept it.
Choose the spot
Follow the manual's placement diagram. Most manuals call for a unit on each level of the home and outside each sleeping area, and they usually specify how far the unit must be from the fuel-burning appliance, from the kitchen, and from direct airflow such as a vent or a fan. Mount at the height the manual gives, not the height you prefer. If the house has a garage with living space above or beside it, check the manual's rule for that layout before you choose a wall.
Mount it safely
Before you drill, check for wiring and plumbing in the wall with a stud finder that detects them, and turn off the water or electrical supply if you are unsure. Use the template and the anchors included with the unit. Mount the base firmly, and make sure the alarm clicks or locks into place. If the unit is hardwired, stop at the wiring and call the electrician for that part of the job.
Test it and record it
Press the test button and confirm that the alarm sounds at full volume. Test each unit in the house, not just one. Copy the end-of-life marking into your phone notes, and set a reminder to replace the unit before that marking arrives. Keep the manual in the same drawer as the other household papers so the next person knows where to find it.
Dad's side of the decision
He may resist a new beeping box on the wall, especially if he feels the house is being managed around him. Ask him to pick the spot with you, using the placement diagram, so he sees the reasoning. Explain that the unit is doing a job he already trusts from the smoke alarm, and let him press the test button himself. Most of the resistance eases once he is the one running the test.
Next move: Tonight, read the box, count the fuel-burning appliances in the house, and mark each planned spot on the wall with painter's tape before you drill anything. Then check the manual's placement rules against your marks.