Warmcast

User guide

What Warmcast does

Warmcast learns how your home gains and loses heat: how fast each room cools, how much heat the floors and walls hold, and how much the sun warms each room. Later it will use that to plan your heat pump's heating ahead in half-hour slots. It will store heat in the house and the hot water tank when energy is cheapest or the heat pump runs most efficiently, and hold back before a sunny day so rooms do not overheat.

Comfort always comes first. Your own thermostats and automations stay in charge and keep the house warm if Warmcast stops.

What this version does

It only reads. Every minute it reads the sensors you listed and adds one row to its own reading log. Each night at 22:00 it tries to learn a model of your house from that log. The Overview tab shows whether the log is being written and what the last nightly refit said.

It publishes no sensors, changes no settings and makes no plans.

What shadow mode means

Shadow mode means Warmcast works out what it would do but does not act on it. You can watch what it would have done and compare it with what happened, with no risk to your comfort. Warmcast always starts in shadow mode. It only acts once you switch it to Advisory or Control yourself.

Until its model passes Gate 2, Warmcast has no tested model to work out what it would do, so for now it reads your sensors and learns. Passing Gate 2 does not switch anything on: it then starts working out what it would do, still without acting on it.

Gate 1 and Gate 2

Warmcast moves forward only when it has passed a check, called a gate, so it never plans with a model that has not been tested.

Gate 1: enough data

At least 14 days with the heating on, including 3 cold days and 3 sunny days, with every sensor recording. Until then the nightly refit may say there is not enough data yet. That is normal.

Gate 2: accurate forecasts

For a week, the model forecasts the warmest part of each day in every room to within about 0.5 °C. The forecast is made the evening before, so it is a fair test. Once Gate 2 is passed, shadow-mode plans and forecasts appear on the Overview and Plan tabs.

How to read the charts

The Charts tab shows the last 24 hours of readings from the log. Every time on the dashboard is in the house time zone from your house settings (Europe/London unless you changed it), not the time zone of the device you are using, so the times match your heating.

If something looks wrong