Opentherm

Links and documentation

• Opentherm gateway
• What is Opentherm?
• File:Opentherm Protocol v2-2.pdf

Nomenclature and abbreviations

OT/+

OpenTherm/plus

OT/-

OpenTherm/Lite

OSI/RM

The OSI 7-layer protocol reference model.

PWM

Pulse-width modulation

Room Unit

The device which calculates the “demand” in the system, which is communicated to the

Boiler Unit.

The use of the term room is not intended to be literally restrictive but is used for convenience.

Boiler Unit

The device which receives the “demand” from the room unit and typically is responsible for providing energy to satisfy that demand. The use of the term boiler is not intended to be literally restrictive but is used for convenience.

AL

Application Layer

DLL

Data-Link Layer

HVAC

Heating, Ventilation, Air Conditioning

• https://friarsair.com/thermostat-modes-settings-mean-explained/

PL

Physical Layer

Setback temperature

The temperature to maintan while you're away

TSP

Transparent Slave Parameter

RBP

Remote Boiler Parameter

CH

Central Heating

DHW

Domestic Hot Water

OEM

Original Equipment Manufacturer

OTC

Outside Temperature Compensation

FHB

Fault History Buffer