Thermostats
Room Thermostat C (mains, volt-free switch)
In short
Room thermostat C is a mains-powered room thermostat (stat) with a volt-free changeover switch. Its terminals: L, N, 1, 2, 3, 4. Units based on makers’ products sit under it in the parts list, such as the Danfoss RET230 and the Drayton Digistat+.
If this is your home: this page is written for heating engineers. Mains wiring and gas appliances are not DIY jobs; call a Gas Safe registered engineer. If you smell gas, leave the building and call the National Gas Emergency Service on 0800 111 999.
What it is
ROOM THERMOSTAT C is a mains-powered room thermostat (stat) with a VOLT-FREE changeover switch.
Its live (L) and neutral (N) feed its electronics. Its 1, 2 and 3 are the switch, with no link to L inside. So you feed the common, 1, yourself.
2 and 4 are this simulator's own: the T6360B has no L, and prints 2 as N and 4 as satisfied. Read the plate.
It comes set at 21 °C. Press - or + to change it by 1 °C, from 10 to 30 °C.
Terminals
| Terminal | What it is for |
|---|---|
| L (LIVE) | The live (L) for its electronics. |
| N (Neutral) | The neutral (N) for its electronics. |
| 1 (Comm) | The common (COM). Feed it with the heating demand. |
| 2 (Satisfied (NC)) | SATISFIED, the normally closed (NC) contact: joined to 1 while the thermostat is satisfied. |
| 3 ((NO)) | The CALL, the normally open (NO) contact: joined to 1 while the thermostat calls. |
| 4 (unused) | Not used. |
What the meter reads
Its live (L) and neutral (N) feed its electronics. It switches nothing until 1 is fed. Then 3 goes live while it calls, and 2 while it is satisfied.
Without its own live and neutral, its switch rests on 2, satisfied, so 3 never goes live.
Put a live on 1, and turn the thermostat (stat) up. No live on 3 means a faulty thermostat.
Units based on makers’ products
In the parts list these sit under the Room Thermostat C. Each is the simulator’s own unit, simplified for teaching, and may differ from the product it is based on: on site, read the unit’s own instructions. DrawWarm is not part of these makers and is not approved by them.
- Based on the Danfoss RET230
- Based on the Drayton Digistat+
- Based on the Honeywell T6360B
- Based on the Danfoss RET230VF
- Based on the Drayton Digistat+3
- Based on the ESi ESRTP5
Where it connects
Lessons that use it
- Room Thermostat C
Foundation · The parts
- A combi's own strip
Intermediate · Reading branded units
- The same on the Y-Plan
Intermediate · Swapping controls
- The practical: commissioning an unseen system
Intermediate · Commissioning
- Combi programmable stat (page 49)
Worcester wiring
- Combi frost protection (page 52)
Worcester wiring
Practise it in the simulator.
Runs in the browser on a laptop or desktop. Cancel any time.