Weather Compensation and Modulating controls for condensing boilers

Associate Members of

Modulating gas heating controls and Weather Compensation

Modulating controls and 'Open Therm' boilers are cost effective and
eco-friendly because they minimise waste and inappropriate energy
consumption. The controller measures room temperature, or outside
temperature in the case of weather compensation*, and calculates the
best use of gas throughout the building. The boiler has an intelligent
interface which will sense and control the burner, heat circulation, hot
water and mixing valves. Optimum Start is also available.

Proprietary modulating controls are designed to work with boilers of the
same brand. For example, Viessmann Vitotronic 200 controls works with
all Viessmann Vitodens boilers; Vaillant controls work with all Vaillant
boilers, and ATAG controllers work only with Atag boilers.

Opentherm controls can be used with all Opentherm-compatible boilers.
For example, Celsia 20 controller (by?) will work with Broag, Atmos and
the Viessmann Vitodens 100 boilers.

OpenTherm
OpenTherm is the name of a non-manufacturer-dependent system of
communication between modulating HVAC heating appliances and room
thermostats. The system consists of a communication protocol and an
interface specification. OpenTherm is futuristic system, which combines
simple installation techniques with high functionality and future expansion
possibilities.

The use of OpenTherm has great advantages for the consumer, the fitter
and the manufacturer, as well as the environmental advantage.

Advantages:

The consumer

The installer

• increased comfort.
• lower fuel costs.
• wider selection of products.
• remote control.
• increased life span.
• extra functionality.
• no batteries required.
• ready for future expansion.

• Installation is as simple as on/off:
– 2 wire low voltage connection.
– no adjustments or tuning.
– tested by closing connection.

• Status of boiler on the display.
• Logo indentifies products.
• Wide selection of products.

The manufacturer

The environment

• Readily available protocols and
interface specification.
• Supported by a growing number
of manufacturers.
• Larger market because of wide
selection of products.

• Less pollution.
• No batteries required.
• Lower energy consumption.
• Lower carbon footprint.

An Open Therm controller improves the efficiency of a compatible condensing

boiler by over 15%. Control circuits are already installed on the control boards

of many boilers so no additional investment is required from the boiler

manufacturer to make equipment OpenTherm compatible.

The Open Therm Association (OTA)’s www.opentherm.co.uk objectives are to

promote the use of the OpenTherm protocol and develop it further throughout

Europe. The OTA is an independent group of 27 manufacturers of products

using the OpenTherm protocol (Honeywell, Danfoss, Theben, Broag-Remeha,

Keston, Johnson and Starley and Mikrofill, etc).

The technology is developing new functionalities. At a 20XX? OTA annual

meeting in the UK, members discussed the development of an OpenTherm

standard for wireless applications. Other developments include integration with

telecommunications (so people can ‘phone home’ to switch on the heating),

and diagnostic facilities to relay boiler fault information to repair engineers.