The Honeywell CM921 Wireless 24Hr Programmable Room Thermostat can be used to control the heating circuit in a Sundial S or Y Plan and is particularly well suited to control combination boiler installations or additional zones in a S Plan Plus system. The Honeywell CM921 Wireless 24Hr Programmable Room Thermostat is for use where heating needs are the same from day to day. The CM927 can provide a different heating programme for each day of the week to maximise energy efficiency. Two wire, volt free connections are ideal for use with combination boilers. Honeywell CM921 Wireless 24Hr Programmable Room Thermostat Product Features: Direct replacement for a Honeywell CM927/CMS927/CM727/CM921, if you are unsure about compatibility please call us on 01302 279234. Wireless connection to the boiler allows you to mount the Chronotherm in your room without disruption

The Pro Series Wireless Programmable Thermostat is a BRAND NEW 2021 launched, 7 day programmable room thermostat designed to replace all existing Honeywell CM Series Wireless Thermostats. The Honeywell CM921 Wireless 24Hr Programmable Room Thermostat series of Wireless Programmable Thermostats is designed to provide wireless time and temperature control to heating or cooling systems in domestic and light commercial buildings. The slim, ultra modern design complements the large LCD screen with the Line of Text (LoT) display and one function button to ensure simplified programming and operation for all users. Honeywell CM921 Wireless 24Hr Programmable Room Thermostat is p art of the Honeywell Controls Range from Plumbarena. Honeywell are one of the market leaders in heating control technology, providing quality products for domestic comfort. Built-in memory holds the user program indefinitely so that it is never lost – even if you remove the batteries Pro Series Wireless Programmable Thermostat | Direct Replacement for Honeywell CM927/CMS927/CMS927B1049 Wireless Programmable Room Thermostat Pro Series Programmable Wireless Thermostat Box contains:The Pro Series Wireless Programmable Thermostat works with the following Honeywell Wireless Relay Boxes: The Honeywell CM921 is a programmable thermostat designed for use in homes and small businesses in the United Kingdom. It features a clear digital display and simple controls, making it easy to set schedules for heating and cooling systems. The device is compatible with a wide range of boilers, making it versatile and suitable for different types of heating systems. The Honeywell CM921 is wireless and can be controlled remotely using the Honeywell Total Connect Comfort app, available for iOS and Android devices. This allows users to adjust their heating schedules and monitor their heating systems from anywhere, at any time. The device also features a frost protection mode that helps to prevent pipes from freezing during cold weather. The Pro Series Wireless Programmable Thermostat will replace the following Honeywell CM Series products:

Pro Series Wireless Programmable Thermostat – Replaces Honeywell CMS927 & CMS921 Wireless Programmable Room Thermostats This is a Pro Series Wireless Programmable Thermostat ONLY and does not include a Wireless Relay Box!The Honeywell CM921 can be programmed for up to six different time periods per day, allowing users to tailor their heating schedules to their individual needs and preferences. The device also features a holiday mode that allows users to set a lower temperature when they are away from home for an extended period of time, helping to save energy and reduce costs. If you take a good look at the Pro Series Wireless Programmable Thermostat, you will see it is nearly identical to Honeywell Home’s T3 Series Thermostat (the user display menu is identical). However, the big difference is that the Pro Series Wireless Programmable Thermostat will bind directly to any existing Honeywell Wireless Relay Boxes, where the T3 Series won’t, so you don’t have the hassle of having to get an installer out to fit this.

The ‘Pro Series’ is made in the UK by Resideo (who were formally part of Honeywell International Inc.) and distributed to independent merchants via a national merchant wholesaler. Resideo (Honeywell Home) is the same manufacturer who made the CM700 & CM900 Series Thermostats. Day Off button copies Sunday’s program into any other day of the week, so that you can make the Pro Thermostat follow this program if you have a day or days off. Optimum Start & Stop saves energy and money by getting to the correct temperature at the correct time and turning off the heating early if the room temperature is correct.

Has anybody come across this problem? Maybe I have to accept I need to have a new receiver and thermostat installed but I just wanted to find out what the problem is with mine first!