Advertising Disclosure
Best Cm921 Replacements of 2026
Best Choice
1
Clicked 1 times in the last monthHanicksHoneywel T4R Wireless 7 Day Programmable Thermostat Y4H910RF4003 (Replaces CM927 CMS927 CM921 CMS921 CM727 CM721) Genuine Part - Hanicks
9.8
Exceptional
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
2
HanicksHanicks Honeywell-Resideo TotalHome CM927 CM921 CM727 CM721 CMS927 CMS927B1049 (Mk3 Replacement) Wireless Room Thermostat & Receiver Kit TTHWFP
9.6
Exceptional
Our Rating
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
Show more
Value for Money
3
TotalHomeTotalHome - Wireless Room Thermostat & Receiver (Honeywell/Resideo) CM927 CM921 CM727 CM721 CMS927 CMS927B1049 (Mk2 Replacement) (TTHWFP)
33% Off
9.5
Excellent
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
4
LavaTapLavaTap Pro Honeywell Wireless Programmable Thermostat CM927 CM921 CM727 Replacement 7 Day Central Heating Programmer Boiler Plus Compliant White Standard
9.4
Excellent
Our Rating
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
Show more
5
Adept TechnologyAdept-Honeywell Wireless Programmable Thermostat Replacement for CM927 CM921 CM727 CM721 CMS927B1049 with Relay Box Central Heating Programmer - White
9.3
Excellent
Our Rating
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
Show more
6
Plumbhub Plumbing and Heating SuppliesPlumbhub-Wireless Programmable Thermostat Replacement for CM927 CM921 CM727 CM721 CMS927B1049 with Relay Box Central Heating Programmer - White
9.1
Excellent
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
Show more
7
LavaTapLavaTap Pro Honeywell Wired Programmable Thermostat CM907 CM901 CM707 CM701 Replacement Central Heating 7 Day Programmer Boiler Plus Compliant
8.8
Very Good
Our Rating
Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service level, popularity, trends and more. The rankings reflect our opinion and should be a good starting point for shopping.
Show more
