# Room thermostat plan mark

Canonical URL: https://eloragrid.ai/symbols/iec-room-thermostat-plan-mark
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: TS
Drawing use: GA
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Thermostat
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

Plan mark for a wall-mounted room thermostat controlling heating or cooling equipment.

## In plain English

### What does Room thermostat plan mark mean?

A room thermostat is drawn as a small circle or square with a temperature mark, a theta or the letter T, at its wall position. A control link connects it to the heater, valve or air-conditioning unit it controls.

### A simple example

Its position affects comfort: it should not be near heat sources, in direct sunlight or on an external wall. The plan gives the designer a chance to check this, and the mounting height is usually stated in notes.

### What the drawings help you do

It does not show whether the thermostat switches mains directly or provides an extra-low-voltage control signal. Wiring type follows the controlled equipment.

### This particular reference

Plan mark for a wall-mounted room thermostat controlling heating or cooling equipment. A schematic temperature switch shows a contact; the plan mark locates the room control.

### Terms

- Signal: Electrical information passed between devices, rather than necessarily the main power supply.
- Rating: A value stating the conditions for which equipment is specified.
- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)


## What it represents

A room thermostat is drawn as a small circle or square with a temperature mark, a theta or the letter T, at its wall position. A control link connects it to the heater, valve or air-conditioning unit it controls.
Its position affects comfort: it should not be near heat sources, in direct sunlight or on an external wall. The plan gives the designer a chance to check this, and the mounting height is usually stated in notes.
It does not show whether the thermostat switches mains directly or provides an extra-low-voltage control signal. Wiring type follows the controlled equipment.

## How to read it

- Check its position relative to heat sources.
- Identify what it controls.

## Information to show or reference

- Link to controlled equipment.
- State control voltage.
- Give mounting height.

## Important distinction

A schematic temperature switch shows a contact; the plan mark locates the room control.

## Facts

- Graphic cue: Circle with temperature symbol
- Placement check: Away from heat sources
- Exact standard graphic: Not reproduced here; confirm the form against IEC 60617 and the project legend

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC graphical symbol context; independently drawn here.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.