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Tutorial 6 — heating and cooling

Part 2 — Tutorials. Continues the project from Tutorial 5.

What you will build

A heated living room that follows a weekly schedule, with a wall button that overrides it.

Heating is the largest topic in iDM3, and it works differently from everything so far. Read §10.1 before you touch anything — it will save you an afternoon.

10.1 How heating is different

Lights are simple: a button acts on an output. Heating has a regulator in between.

You never wire a temperature sensor straight to a boiler. Instead you define a Heat/Cool area — a self-contained controller that owns the sensor, the valve, the boiler demand, and the schedule. It runs continuously inside the central unit, comparing the measured temperature against whatever the schedule currently asks for.

   ┌──────────────────────────────────────────────────────┐
   │  HEAT/COOL AREA  "Living room"                       │
   │                                                      │
   │   Time plan  ──▶ wanted temperature                  │
   │                        │                             │
   │   Thermosensor ──▶  compare  ──▶ Heating output      │
   │   (GRT3-50)            │         (valve)             │
   │                        └──────▶ Heating supply       │
   │                                  (boiler demand)     │
   └──────────────────────────────────────────────────────┘
            ▲
            │  wires only *nudge* the area:
            │  "switch to Favorite4", "stop the program"
         a button

So there are three things to build, in this order:

What
Where

1

A time plan — the temperature schedule

System manager → System programs

2

A Heat/Cool area — the regulator

System manager → Heat/Cool areas

3

Wires — buttons that override the schedule

Wire manager

Steps 1 and 2 involve no wires at all. Once they are right, the heating works on its own.

10.2 Step 1 — Add the hardware

  1. Project → Device manager → select Internal-Master/BUS1.

  2. New unit → GRT3-50 (room thermostat with temperature sensor) → OK. Address it, describe it Living room thermostat.

  3. New unit → SA3-02M if you do not have a spare relay output → address and describe it Living room valve.

  4. Close and save.

You need at minimum: something that measures temperature, and something that switches the heat.

10.3 Step 2 — Build the time plan

The time plan says what temperature is wanted, hour by hour, across the week.

  1. Managers ribbon tab → System manager → System programs tab.

  2. Click +. The Select program type dialog appears.

  3. Choose Heating/Cooling - week — a full weekly plan, plus a holiday variant. (Heating/Cooling day defines a single-day plan, used for public holidays.)

  4. OK. The Program details panel becomes editable.

Fill in the temperatures

Field
What it means
Set it to

Program name

how you will refer to it

LIVING_ROOM_HEATING

Default

the baseline temperature for the whole week, wherever you have not said otherwise

18

Favorite1

your four preset temperatures — reusable everywhere

16

Favorite2

18

Favorite3

20

Favorite4

22

Visible range Min view / Max view

just the vertical scale of the graph

10 / 26

All temperature fields accept −40 °C to +200 °C in 0.1 °C steps. The wide range is for industrial use; a house lives between 15 and 25.

Favorites are the vocabulary of your heating system. Buttons, thermostats and the Monitor all switch between Favorite1–4, not between raw numbers. Decide what your four mean — night, away, normal, comfort — and keep them consistent across every area in the building.

Draw the schedule

The yellow graph is one day, 00:00 to 24:00. You place time stamps — up to 16 per day — and set the temperature between them.

  1. Select a day.

  2. Click Mark to add a single time stamp. Click Mark then Window to add a pair, which is what you want for "warm from 06:00 to 08:00".

  3. Move a stamp either by dragging its line, or by clicking its time label and typing a new time.

  4. Set the temperature for a stretch by dragging the horizontal line up or down — or right-click in the yellow area and pick Default or Favorite1–Favorite4 from the list.

A typical weekday:

Time
Temperature

00:00 – 06:00

Favorite1 (16 °C) — night

06:00 – 08:00

Favorite4 (22 °C) — morning

08:00 – 16:00

Favorite1 (16 °C) — empty house

16:00 – 22:00

Favorite3 (20 °C) — evening

22:00 – 24:00

Favorite1 (16 °C)

Copy it to the other days

Do not draw this seven times.

  1. Right-click the day label. A copy dialog opens.

  2. Tick the target days, or use Working days, Weekend, or All week.

  3. Click Copy actual program.

Then adjust the weekend separately — that is usually the only day that differs.

  1. Click ✓ to save the program.

Time plans can be edited live. Once the project has been uploaded once, you can change a time plan and push just that change with ✓ — no full re-upload. Very handy when a client wants the morning warm-up half an hour earlier.

10.4 Step 3 — Define the Heat/Cool area

  1. System manager → Heat/Cool areas tab.

  2. Click + above the Heat/Cool list. A new controller appears.

  3. Work through its three sub-tabs.

Parameters

Field
Set it to

Address

filled in by iDM3 — leave it

Description

Living room

Control type

see below

Plan-Heating

LIVING_ROOM_HEATING

Thermostat 1

your GRT3-50

Control type has three options and it decides how heating and cooling co-exist:

Option
Use when

User control heating / cooling

the user switches between heating and cooling from a controller input

H/C automatic control - two temperatures

heating and cooling each have their own target; the system picks based on the measured temperature

H/C automatic control - one temperature

one target for both, switched by hysteresis

For heating only, pick any of them — the cooling side simply stays unused. Start with User control heating / cooling.

The other plan slots — Plan-Cooling, Holiday Plan-Heating, Holiday Plan-Cooling, Public holiday Plan-Heating, Public holiday Plan-Cooling — take further programs you define the same way. Leave them empty for now.

You can attach up to 6 thermostats per area with Add and Remove.

Connections

This is where the area meets real hardware. Click the pencil icon to edit.

Field
What to attach

Thermosensor

the temperature input that measures the room — your GRT3-50

Heating regulator

filled in automatically if you added a regulator in Device manager

Heating output

the relay driving the valve or floor-heating actuator

Heating supply

the relay that demands heat from the boiler

Critical temperature sensor

floor-heating temperature limit — optional

Cooling regulator / output / supply

the cooling equivalents

The minimum set for heating only: Heating time plan, Heating regulator, Heating output, and Heating supply.

For heating and cooling you need all eight: both time plans, both regulators, both outputs and both supplies.

Heating output vs Heating supply. Output is this room's valve. Supply is the boiler, and it is shared — it fires when any area asks for heat. Wire every area's supply to the same relay.

Online parameters

Safety limits and behaviour. Click the pencil to edit.

Field
What it does

Maximal temperature

heating will never push above this

Antifreeze temperature

heating will never let the room fall below this

Restart regulator after closing window

how long heating stays off after a window opens

Maximal close window time

after this, an open window is ignored and heating resumes

Manual mode on time

how long a manual override lasts before the schedule resumes

Public holiday

dates that use the public-holiday plan

Always set Antifreeze temperature. It is the one setting that protects the building when everything else is wrong — a bad schedule, a failed sensor, a client who set 5 °C by mistake.

Click ✓ to save the area, and save the project.

10.5 Step 4 — A button that overrides the schedule

The heating now runs by itself. A wire's job is only to nudge it.

  1. Design workspace tab → place a button icon, Connect it to a spare GSB3-40 button, name it Heating boost.

  2. Function workspace tab → Add connection → drag from Heating boost to the Heat/Cool area object.

  3. Wire manager → name the wire Heating boost → +:

    • Action: Short down

    • User function: HEATING_COOLING_SWITCH_TO_FAVORITE4

  4. Add a second: Action Long down, User function HEATING_COOLING_SWITCH_TO_FAVORITE1.

  5. Close, save, upload.

Short press → 22 °C. Long press → 16 °C. The schedule takes over again when the manual period expires.

The heating functions

The default project provides these ready to use:

Function
Effect

HEATING_COOLING_SWITCH_TO_FAVORITE1

set the area to Favorite1 (Heat cool set program minimum)

HEATING_COOLING_SWITCH_TO_FAVORITE2

Favorite2 (…set program attenuate)

HEATING_COOLING_SWITCH_TO_FAVORITE3

Favorite3 (…set program normal)

HEATING_COOLING_SWITCH_TO_FAVORITE4

Favorite4 (…set program comfort)

HEATING_COOLING_START

start the time program

HEATING_COOLING_STOP

stop it — the area holds its current setting

HEATING_COOLING_NORMAL_PLAN

switch to the ordinary weekly plan

HEATING_COOLING_HOLIDAY_PLAN

switch to the holiday plan

HEATING_COOLING_PUBLIC_HOLIDAY_PLAN

switch to the public-holiday plan

HEATING_COOLING_SWITCH_TO_HEATING

force heating

HEATING_COOLING_SWITCH_TO_COOLING

force cooling

HEATING_COOLING_CANCEL_MANUAL

drop any override and return to the schedule

Favorite1 is "minimum" and Favorite4 is "comfort" internally. The names come from an older version of the system where the four presets were called minimum, attenuate, normal and comfort. The numbering is what you will see on screen; the old names appear in the underlying function names. They are the same four settings.

There are many more heating functions than these — setting an explicit temperature, holding one until a given time, changing the antifreeze limit. See Appendix B.

10.6 A holiday plan

  1. Build a second week program — LIVING_ROOM_HOLIDAY, everything at Favorite1.

  2. In the Heat/Cool area, set Holiday Plan-Heating to it.

  3. Wire a button to HEATING_COOLING_HOLIDAY_PLAN, and another to HEATING_COOLING_NORMAL_PLAN.

One press before leaving drops the whole house to its minimum; one press on return restores the schedule.

10.7 Checking it works

Heating is slow, so do not judge it by watching a radiator.

Use Managers → Monitor → Heat/Cool areas. It shows, live from the central unit: the measured temperature, the wanted temperature, which favorite is active, and whether the outputs are on. That tells you in seconds whether your area is configured correctly.

Chapter 26 covers the Monitor properly.

What you learned

  • Heating is a regulator, not a wire — the Heat/Cool area runs continuously in the CU

  • Build it in order: time plan → area → wires

  • Favorite1–4 are the shared vocabulary of the whole heating system

  • Up to 16 time stamps per day; copy days rather than redrawing them

  • Output is this room's valve; supply is the shared boiler demand

  • Always set the antifreeze temperature

  • Time plans can be edited live, without a full re-upload

Try this before moving on

  1. Add a second area for the bedroom with its own plan but the same Heating supply.

  2. Give the weekend a later morning warm-up.

  3. Watch Monitor → Heat/Cool areas while you press your boost button and see the wanted temperature change.

Next: Chapter 11 — Tutorial 7: time control — schedules for everything that is not heating.

PreviousTutorial 5 — blinds and shutters
NextTutorial 7 — time control