There are 3 smoke alarms and 2 CO2 alarms located within the property.

Smoke Alarm:

Manual: Kidde 10Y29

Smoke Alarm #1: Front hall above front door
Smoke Alarm #2: Kitchen above fridge freezer
Smoke Alarm #3: Upstairs landing above stairs

Extract from Smoke Alarm manual:

TESTING: Test by pushing the test/Hush button on the cover and holding it down for a minimum of 1 second (or until the alarm sounds). Note: the first test sequence will be at a lower volume. Holding the test/Hush button for longer than 5 seconds will result in the full 85 decibel sound output. This will sound the alarm if the electronic circuitry, horn, and battery are working. If no alarm sounds, the unit has a defective battery or other failure. DO NOT use an open flame to test your alarm, you could damage the alarm or ignite combustible materials and start a structure fire.

SMOKE SENSING CHAMBER OPERATION: This alarm will "chirp" every 30 seconds (with red LED flash at the same time) if it detects a problem with the smoke sensing chamber. 

NOTE: WEEKLY TESTING IS REQUIRED.

CO2 Alarm:

Manual: Kidde 5CO

CO2 Alarm #1: Kitchen to the right hand side of the wood burning stove
CO2 Alarm #2: Loft to the left hand side of the combi boiler.  Attached to the hand rail.

Extract from CO2 Alarm manual:

Testing 

Each week your alarm should be tested by pressing the test button. The alarm will beep once followed by 4 loud pulses, then a brief pause and then 4 more pulses, ending with a single beep.

During this test sequence, the red LED will flash for 10 seconds.

This confirms that the alarm is powered up and working.