Thermostat TH 091

Product detailed description

The AVANSA TH091 programmable thermostat is designed for integration into residential and commercial heating systems, particularly those using gas, electric, wood, coal, or pellet boilers. It is commonly installed in homes, weekend cottages, and small commercial buildings where precise temperature control and energy efficiency are required. The device operates with a two-point switching system, making it suitable for systems that require on/off control of heating appliances. Installers should consider the minimum cycle time and the need for accurate temperature regulation when selecting this thermostat for a specific application.

Its compact dimensions (154 x 80 x 30 mm) allow for easy mounting on walls in standard electrical boxes. The thermostat is battery-powered and does not require a separate power supply, making it ideal for installations where access to mains electricity is limited. The device is particularly useful in systems where a weekly schedule is needed to manage heating demand efficiently, such as in homes with variable occupancy patterns or in buildings with seasonal use.

Technical parameters

Installation and connection

Installation of the AVANSA TH091 involves mounting the device on a dry, accessible wall surface and connecting it to the boiler’s control circuit using standard wiring. The thermostat supports 0–230 V AC 50 Hz switching and must be connected to a boiler that supports two-point switching. Installers should verify that the boiler’s switching capacity is within the thermostat’s rated current (5 A). The use of the supplied mounting hardware ensures secure installation and alignment with the wall surface.

Common installation mistakes include incorrect wiring of the switching contacts or failure to account for the minimum cycle time when setting up the weekly program. It is also important to ensure that the thermostat is installed in a location free from direct sunlight or heat sources that could affect temperature readings. The use of a backlit display aids in programming and monitoring the device during installation and commissioning.

Compatibility and accessories

The AVANSA TH091 is compatible with a wide range of boilers, including condensing models such as Junkers Compact, Viessmann Vitodens 100, and ATTACK. It is suitable for gas, electric, and solid fuel boilers that use two-point switching. The thermostat is often used in conjunction with the Avansa 2007 model for additional control options. The device comes with an installation manual, mounting screws, and dowels for secure wall mounting. No additional accessories are required for basic operation.

Technical background for designers

The AVANSA TH091 operates by measuring ambient temperature and comparing it to the setpoint defined in the weekly program. When the measured temperature falls below the setpoint, the thermostat closes the switching contacts to activate the boiler. The device uses a digital microprocessor to manage the weekly schedule and temperature control functions. The use of alkaline batteries ensures stable operation without voltage fluctuations that could affect performance.

The thermostat’s housing is designed for durability in typical indoor environments, with a temperature range of 0 to 40°C and a humidity range of 5 to 90% without condensation. The device integrates into standard electrical systems and is suitable for use in both new and retrofit installations. The minimum cycle time of 5 minutes helps prevent excessive boiler cycling, which can reduce system efficiency and increase wear on components.

Service and operation

Regular maintenance of the AVANSA TH091 involves checking the battery level and replacing the alkaline AA batteries when the device indicates low power. The thermostat does not require scheduled service intervals beyond battery replacement. Installers should verify the accuracy of temperature readings and the integrity of the switching contacts during routine inspections. The device’s internal clock has a precision of +/- 70 seconds per month, which should be checked periodically to ensure accurate program execution.

Common operational checkpoints include verifying that the thermostat is correctly programmed for the weekly schedule and that the boiler responds to the switching signals. If the device fails to activate the boiler, the installer should check the wiring and the boiler’s control system for faults. The thermostat’s display provides visual feedback on the current and set temperature, the selected program, and the heating or cooling status.

Frequently asked questions

Can the AVANSA TH091 be used with a condensing boiler?
Yes, the thermostat is compatible with condensing boilers such as Junkers Compact and Viessmann Vitodens 100, provided they support two-point switching.

How many temperature settings can be programmed?
The device allows 6 preset programs and 3 user-defined programs, each with separate temperature settings for heating and cooling modes.

What is the minimum cycle time for the thermostat?
The minimum cycle time is 5 minutes, which helps prevent short cycling and ensures stable boiler operation.

Can the thermostat be used for cooling applications?
Yes, the thermostat supports both heating and cooling modes, making it suitable for systems that require temperature control in either direction.