Limited life on Kidde is 5 years as per Guarantee; which is 5 times
longer than patch!
One at Argos {New cat from yesterday} has benefit of digital display
too, at same price as B&Q's without!

Absolutely not a substitute for servicing; but in my experience gas
cooker grills regular
cause.

Few people have this appliance serviced; even tenants who have
landlords appliances
checked by Corgi engineer annually {in UK}. Cooker in 95% of cases is
not owned by landlord except HMO type dwellings.

HSE research into long term reliability* of CO alarms found Kidde [then
also called Nighthawk on some models] & 1 other make, hard to find at
retail, were ONLY ones reliable.

*Majority [using cheap co sensor cells] drift off specification after
year or so, so don't respond as they are meant to, giving people false
sense of security.