Oregon carbon monoxide alarm rules for landlords: alarms before move-in, batteries and written testing instructions

What must be in place before a new tenancy?

A landlord may not enter a rental agreement creating a new tenancy if the unit contains a carbon monoxide source, or is in a structure with a source and is connected to the room holding it by a door, ductwork or a ventilation shaft, unless properly functioning CO alarms are installed under State Fire Marshal rules. If an alarm is battery operated or has a battery backup, the landlord supplies working batteries at the beginning of a new tenancy.

What must the tenant be told?

The landlord gives written instructions for testing the alarms no later than when the tenant first takes possession. Written means a document the tenant can keep, and a record that you handed it over. A line in the move-in checklist, signed by the tenant, covers it.

Example a made-up owner in Eugene hands each new tenant a one-page sheet: where the alarm is, how to press the test button, what the chirp means and whom to call. The tenant signs the checklist line that says the sheet was received.

What happens when an alarm fails during the tenancy?

If the tenant gives the landlord written notice of a deficiency in a CO alarm, the landlord must repair or replace it. The repair duty excludes dead batteries. Supplying and maintaining a required CO alarm is also a habitable condition requirement under ORS 90.320, which means the usual habitability consequences can follow. The pages I read did not address tenant battery duties, tenant liability or penalties, and they cover carbon monoxide only. Smoke alarm rules are elsewhere in Oregon law and are not described here.

Where Oregon owners slip

The first slip is renting a unit that has a CO source but no alarm, usually in a house with an attached garage or a gas furnace in a closet. Walk every unit and mark which have a source; the connected-by-door or duct language catches more units than owners expect. The second slip is missing the battery line: if a battery alarm is installed, the batteries must be supplied at the start of each new tenancy, and a spare in the unit is a good record. The third is treating the written-notice rule as a casual ask. Log the date of every written alarm complaint and the date you fixed it.

Mapping which Oregon units need alarms

Because the rule turns on carbon monoxide sources, start with a short survey. List each unit's gas or oil furnace, water heater, range, fireplace and attached garage, and note which rooms connect to those sources by a door, ductwork or ventilation shaft. Mark each unit that needs an alarm and record the alarm's location and model. Revisit the list whenever an appliance is replaced, because a new source can change the answer. The survey takes an hour per building and doubles as the proof that the alarms were in place before the tenancy began.

How DoorKeeping fits in Oregon

DoorKeeping keeps a Oregon unit's alarm checks as dated work orders with photos, so the move-in test, the tenant's reports and your fixes are on the record. The testing sheet and the signed checklist line are stored with the lease. This is general information, not legal advice. Check the current statute, your local fire code and your lease before you act.

Sources

1. Oregon Revised Statutes 90.316 and 90.317, Carbon monoxide alarms (Oregon Revised Statutes, Chapter 90), read Oct 30, 2026

Questions

Do Oregon landlords have to provide CO alarms?

Yes, for units with a CO source or connected to one, before a new tenancy begins, installed under State Fire Marshal rules.

Who supplies batteries in Oregon?

The landlord supplies working batteries at the beginning of a new tenancy for battery-operated alarms.

What must an Oregon landlord do if a CO alarm fails?

Repair or replace it after written notice from the tenant. The duty excludes dead batteries.