🔥 PumpSteer

Smart heat pump optimization for Home Assistant.

PumpSteer is a Home Assistant custom integration that saves money on electricity by dynamically adjusting the virtual outdoor temperature sent to your heat pump controller — without any cloud dependency, machine learning, or black-box logic.

Everything PumpSteer does is explainable directly from its inputs.

How it works

Your heat pump has a heating curve: the colder it thinks it is outside, the harder it heats. PumpSteer sits between your outdoor sensor and the heat pump controller and sends a calculated fake outdoor temperature instead of the real one.

By raising the fake temperature during expensive electricity slots, the heat pump reduces output and saves money. By lowering it before expensive periods, the house pre-heats while electricity is still cheap.

A PI controller maintains indoor comfort at all times. Price and forecast signals are overlays on top of the PI output — never replacements for it.

fake_outdoor_temp = PI_output + brake_overlay + preheat_boost

Key features

Feature	Description
PI control	Maintains indoor temperature at your target regardless of weather
Price braking	Reduces heating during expensive electricity slots (P80 threshold)
Pre-brake	Starts brake ramp before the expensive slot begins, while comfort allows
Preheat boost	Builds bounded thermal reserve before expensive periods when the forecast supports it
Thermal headroom	Saving level limits how far preheat may charge above target
Comfort floor	Brake and pre-brake release automatically if indoor temp drops too far
Brake hold	Bridges only short gaps between nearby expensive periods without ramp oscillation
Summer / precool	Pass-through in summer plus forecast-based warm-period protection
Ohmigo support	Pushes fake temp directly to Ohmigo WiFi controller
Ohmigo Relay Guard	Optional recovery of a configured Active/Bypass relay, outside the control loop
Generic Output System	Optional service-based output to Modbus, MQTT, ESPHome and other HA targets
Holiday mode	Lowers target to 16 °C during absence
Fully local	No cloud dependency and no black-box control loop

Documentation

Operating modes

Mode	What triggers it
`normal`	Default PI control
`braking`	Current price slot is expensive and comfort allows braking
`brake_hold`	Existing brake factor is held across a short gap before another expensive period
`pre_braking`	Expensive slot is imminent, within ramp window, and comfort allows
`preheating`	Expensive period is imminent, forecast supports preheat, and thermal headroom remains
`precool`	Warm-period risk triggers a temporary protective brake ramp
`summer_mode`	Outdoor temp ≥ summer threshold
`safe_mode`	Required temperature or price input is missing/invalid
`holiday`	Holiday target is active during otherwise normal PI operation

Requirements

Home Assistant 2023.12 or later
A Nordpool (or compatible) electricity price source exposing today / raw_today and tomorrow / raw_tomorrow price lists
An indoor temperature sensor
An outdoor temperature sensor
(Optional) A weather entity for forecast-based preheat
(Optional) An Ohmigo device for direct hardware push

Disclaimer: Heating is a critical system. Use PumpSteer at your own risk. Always monitor behavior after installation and ensure your fallback (safe mode) works correctly.