AVANSA thermostat TH 2A

Product detailed description

The AVANSA TH 2A is commonly used in residential and commercial heating systems to manage the operation of circulation pumps based on measured temperature. Installers typically use it in boiler circuits of solid fuel boilers, DHW systems or storage tank charging applications where precise temperature-based control is required. The thermostat is mounted directly onto metal piping using a spring-loaded clamp and reacts to changes in pipe surface temperature to trigger pump activation or deactivation. This makes it particularly useful in applications requiring delayed pump operation after boiler firing or ensuring minimum flow conditions.

The device is well-suited for environments where space is limited and a compact, self-contained solution is needed. Its mechanical design eliminates the need for external power sources beyond the control circuit, making it ideal for retrofitting existing systems or use in low-voltage control schemes. The IP 20 rating indicates that it should be installed in dry indoor locations, away from moisture or condensation risks.

Technical parameters

Installation and connection

The thermostat is installed using a flexible steel clamp that secures it to the pipe. The clamp must be tightened sufficiently to ensure good thermal contact between the device and the pipe surface. It is recommended to mount the thermostat on a vertical section of the pipe to avoid air pockets affecting temperature readings. The control wires are terminated at screw terminals and should be secured with insulated connectors. Prior to energising the system, the installer must verify correct polarity and insulation resistance to prevent faults. Common installation errors include insufficient tightening of the clamp, incorrect positioning near valves or expansion joints, and improper wiring causing false triggering.

Compatibility and accessories

It is suitable for integration with solid fuel boiler controls and DHW storage systems where temperature-based pump activation is required. When installing multiple thermostats in parallel, additional wiring and junction boxes may be necessary. Accessories such as extension cables or mounting brackets are not included in the standard package and should be sourced separately.

Technical background for designers

The AVANSA TH 2A operates using a bimetallic strip that bends in response to temperature changes. As the pipe surface heats, the strip deforms, closing or opening the electrical contact depending on the setpoint. This mechanical action eliminates the need for electronic components, resulting in a robust, long-lasting solution. The device is constructed with a durable housing made of thermoplastic to resist deformation at elevated temperatures. For effective operation, the thermostat must be mounted on a clean, un-insulated metal pipe surface to ensure accurate heat transfer. Environmental factors such as vibration and exposure to extreme ambient temperatures may affect long-term performance.

Service and operation

Periodic inspection of the clamp and wiring connections is recommended to ensure secure attachment and prevent false triggering. The bimetallic element should be visually checked for signs of warping or corrosion. If the thermostat fails to respond to temperature changes, recalibration is not possible due to the fixed construction. In such cases, replacement is necessary. No scheduled maintenance intervals are specified in the documentation, but it is advisable to test functionality during routine system checks.

Frequently asked questions

Can the AVANSA TH 2A be used for underfloor heating systems?
It is suitable for use as a safety thermostat to shut down the pump in underfloor heating systems, but not for primary regulation due to its fixed differential and limited adjustment range.

Is the thermostat adjustable to different temperature settings?
Yes, the setpoint can be adjusted manually using the control knob to match the desired operating temperature range.

What type of pipe diameters can the thermostat be mounted on?
It can be mounted on pipes up to a maximum diameter of 2 inches using the flexible steel clamp provided.

Can the AVANSA TH 2A be integrated with programmable room thermostats?
Yes, it functions independently but can be used in parallel with other control devices to provide additional temperature-based switching capabilities.