Archives for room thermostat

Choosing a Room Thermostat

Honeywell Room Thermostat

We have invited Aaron, an experienced Heating Engineer, to tell us what he thinks you should consider when choosing a new Room Thermostat:

“When looking to install temperature control for your central heating system there are a multitude of thermostats available. The majority of people cannot differentiate between all of the different options and may automatically decide based on cost. Trying to decide on cost could actually end up costing more if you do not purchase a suitable room thermostat for your system or needs.

Wired or Wireless?

The majority of homes have a wired room thermostat installed, where the wires usually run inside the wall from the room thermostat to the wiring centre or boiler. If you want to replace a wired thermostat then it can be replaced with a wired or wireless room thermostat.

In the case of a wired thermostat the location is fixed unless you re-run the wires or replace it with a wireless room thermostat, and then the sensor can be positioned with freedom.

Volt-free, Low Voltage or 230 Volts

There are three different power options for wired room thermostats; volt-free, low voltage (usually 24 volts) and 230 volts. The thermostat you require will be determined by the boiler and system you have installed. In the majority of cases it is only combination boilers that require volt-free or low voltage room thermostats and the manufacturer’s instructions should be consulted.

Digital or Analogue

When deciding whether to choose between an analogue or digital room thermostat there are two considerations in my mind: Cost and the ability of the end user.

If you are on a budget then an analogue room thermostat would be the obvious choice. A digital room thermostat is more expensive but can be more accurate and better looking.

For the end user the analogue room thermostat is the most simple and straightforward to use. Especially when considering a room thermostat for the elderly or infirm a room thermostat with easily visible temperature scale and easy to turn dial will be required. Some of the digital room thermostats can be difficult to see and understand for the elderly and infirm.

On/Off or Programmable


Fitting a programmable room thermostat will give you more flexibility when controlling your heating system. This flexibility can lead to complication and difficulty in setting the thermostat. The ease of setting the thermostats will depend largely upon the make and model fitted. Having a large display which is backlit will help greatly.

The majority of people when thinking about how their room temperature is controlled think about it as being either ‘on’ or ‘off’. In my mind this is faulty thinking and is difficult to explain away and doesn’t help when people try to understand the setting of their programmable room thermostat. The room thermostat is there to regulate the room temperature at a desired temperature as set by the user. If for example the thermostat is set to 20 degrees, the heating should be on until the room temperature reaches 20 degrees (unless the programmer switches off). If the thermostat is turned down to 15 degrees the room temperature will fall until it reaches 15 degrees and the central heating will come on to maintain that temperature. With the use of a programmable room thermostat the different temperatures can be maintained automatically throughout the day for user comfort.

Where cost or the ability of the user is a concern a traditional analogue thermostat would be the best choice, either wired or wireless depending upon the installation.

Other Features

  • Temperature limiting stops – prevents the thermostat from being adjusted above or below a pre-set limit.
  • Setback Function – The set temperature is reduced at the press of a button.
  • Chrono-proportional cycle rate – The number of times per hour which the thermostat clicks on and off at can be altered to reduce the on-off firing of the boiler and intrusion of clicking from the thermostat. Also used for setting the thermostat for use with different types of heating emitters.
  • Automatic summer/winter change – eliminates the need to adjust the clock when the clocks change.
  • Frost protection – A mode which sets the temperature to a desired minimum to protect the heating system when the home is not occupied.
  • Optimal start control – The room thermostat tries to come on before the set time in order that the room temperature is achieved at the set time.
  • 24 hour, 5/2 day, 7 day settings – Programmable for either the same every day (24 hour), different settings for the weekdays to weekend (5/2 day) or different every day of the week (7 day).
  • TPI Control – As the room temperature is neared the thermostat demands the b oiler to fire for shorter periods helping to maintain the room temperature.
Honeywell CM927

Honeywell CM927


If I had to recommend a room thermostat it would depend upon the installation and the user’s requirements/ability.

  •  Wireless Programmable Room Thermostat – Honeywell CMT927
    Large, easy to use, backlit display with many features. 7 day programmable but can also be used as a simple manual thermostat.
  • Wireless Digital Room Thermostat – Honeywell DT92E
    A wireless version of the Honeywell DT90E. Simple to use digital thermostat with a variety of useful features such as an eco set-back function.
  • Wireless Analogue Room Thermostat – Honeywell Y6630D
    Only slightly cheaper than the digital Honeywell DT92E, but a good choice if you need a wireless analogue thermostat.
  • Wired programmable Room Thermostat – Honeywell CMT907
    Wired version of the Honeywell CMT927. Large, easy to use, backlit display with many features. 7 day programmable which can also be used as a simple manual thermostat.
  • Wired Digital Room Thermostat – Honeywell T90E
    Simple to use digital thermostat with a variety of useful features such as an ‘eco’ set-back function.
  • Wired Analogue Room Thermostat – Honeywell T6360B
    Classic design, with simple and reliable construction. Relatively easy to read scale, with markings at every degree. Large easy to turn dial.
Honeywell CM907

Honeywell CM907

As you may have noticed I am a big fan of Honeywell products and would generally choose them over other makes if cost was not a deciding factor. Even when there are options available which are much lower in cost it may not be advisable to purchase them as they may not be as easy to use or have the same functions.”About this article: Aaron was invited to write this article for Direct Heating Supplies. He is an experienced heating engineer of over 10 years and writes his own Gas Central Heating Blog.


Make way for the new Vaillant VRT350F Wireless Room Thermostat

VRT350 Room Thermostat

VRT350 Room Thermostat

If you want the latest heating control technology from Vaillant then look no further than the Vaillant VRT 350F Wireless Room Thermostat. 

As a direct replacement for the now discontinued Vaillant VRT392F Wireless Room Thermostat, the VRT350F offers a lot more functionality for roughly the same price.

Overview of main functions:

  • Wireless control
  • Easily fixes into fascia of Vaillant ecoTEC boilers (additional controls required for System & Open Vent boilers)
  • Blue back light display
  • 1 rotary knob and 2 push buttons
  • Holiday and Calendar functionality
  • Automatic summer/winter time change over
  • Advanced override setting
  • 3 unique time setting options
  • Frost protection

What’s Included?

When you purchase your VRT350F you will be provided with:

  • 1 x Receiver Unit
  • 2 x Control unit
  • 4 x AA batteries (for use in wireless control unit)
  • 2 wall fixing kits
  • Installation and User Manuals
Full contents of the VRT350F Room Thermostat

Full contents of the VRT350F Room Thermostat

The system is nice and easy to use and for the most part you should just need to know how to use the receiver and control units.


Receiver unit:

The receiver unit connects to the front fascia of all Vaillant EcoTEC boilers.

For new Vaillant boilers (purchased after April 2012) you just align the receiver unit pins and push it in. For all Vaillant boilers purchased prior to April 2012 you remove these receiver unit pins and instead slot the receiver unit into the pins that are present on the front of your boiler.

You may need additional controls and extra wiring if you want to use the VRT350F Room Thermostat with a System boiler or other Open Vented boilers. If in doubt please consult the installation manual below or contact the Vaillant support team on 0844 693 3133.

The receiver unit talks to the heating control unit using radio waves and ensures that your heating system is working as per your specified requirements.

Control unit:

It is nice and simply to programme your 3 temperature settings thanks to the rotary knob and 2 chunky push buttons. The Thermostat does not light up when it is not in use but has a blue back light when it is being used.

The calendar function helps provide a seamless transition between summer and winter time periods and with the option for holiday mode, you can even dictate when your central heating goes off when you are going to be away from your property for a sustained period of time.

The wall mounting base that comes included in the pack allows you to simply attach the receiver unit to the wall and operate it wireless. This wireless functionality however means you can opt to use the control unit in a stand alone fashion.


Where can I buy a VRT350F?

Direct Heating Supplies sell the Vaillant VRT350F Wireless Room Thermostat at a really low price.