SAT won't start heating even when the temperature is clearly below target

[sergimola]

I had SAT working fine for a couple of days with EMS-ESP and a Bosch Condens 1200W boiler.
Today I had to cut the power and ever since the power came back (even though Home Assistant was up all the time connected to a UPS) SAT has been misbehaving.

It's in Heat - Idle even though the current temperature is 0.7C below target.

But also the Error Value Living Room doesn't seem to be right. It shows 0.2C instead of 0.7C.

Logs don't seem to tell much

2025-12-29 15:23:30.738 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:10.365 DEBUG (MainThread) [custom_components.sat.relative_modulation] Relative Modulation initialized for heating system: radiators

2025-12-29 15:24:10.365 DEBUG (MainThread) [custom_components.sat.pwm] Initialized PWM control with duty cycle thresholds - Lower: 15.00%, Upper: 85.00%

2025-12-29 15:24:10.365 INFO (MainThread) [custom_components.sat.pwm] PWM control reset to initial state.

2025-12-29 15:24:10.366 DEBUG (MainThread) [custom_components.sat.mqtt] Publishing MQTT command: payload='{"cmd": "heatingtemp", "value": 65.0}', topic='ems-esp/boiler', simulation='False'

2025-12-29 15:24:11.375 INFO (MainThread) [custom_components.sat.coordinator] Set maximum setpoint to 65°C

2025-12-29 15:24:17.275 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/status]

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/info]

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/shower_active]

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler]

2025-12-29 15:24:17.276 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:18.800 DEBUG (MainThread) [custom_components.sat.relative_modulation] Relative Modulation initialized for heating system: radiators

2025-12-29 15:24:18.800 DEBUG (MainThread) [custom_components.sat.pwm] Initialized PWM control with duty cycle thresholds - Lower: 15.00%, Upper: 85.00%

2025-12-29 15:24:18.800 INFO (MainThread) [custom_components.sat.pwm] PWM control reset to initial state.

2025-12-29 15:24:18.801 DEBUG (MainThread) [custom_components.sat.mqtt] Publishing MQTT command: payload='{"cmd": "heatingtemp", "value": 65.0}', topic='ems-esp/boiler', simulation='False'

2025-12-29 15:24:20.104 INFO (MainThread) [custom_components.sat.coordinator] Set maximum setpoint to 65°C

2025-12-29 15:24:30.740 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:24:30.740 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:40.736 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:24:40.736 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:50.743 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:24:50.743 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:24:50.786 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:24:50.786 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:25:00.746 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:25:00.747 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:25:30.753 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:25:30.753 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:25:40.745 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:25:40.745 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:25:50.796 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:25:50.796 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:26:00.741 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:26:00.741 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:26:10.736 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:26:10.736 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:26:20.742 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:26:20.743 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:26:50.789 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:26:50.789 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:27:20.813 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:27:20.813 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:27:50.793 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:27:50.793 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:28:20.754 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:28:20.754 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:28:30.763 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:28:30.764 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:28:40.796 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:28:40.797 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:28:50.792 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:28:50.792 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:29:00.749 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:29:00.749 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:29:10.752 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:29:10.752 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:29:50.775 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:29:50.775 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:29:50.803 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:29:50.803 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:30:00.775 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:30:00.775 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:30:10.743 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:30:10.743 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:30:20.741 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:30:20.741 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:30:40.760 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/boiler_data]

2025-12-29 15:30:40.760 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

2025-12-29 15:30:50.808 DEBUG (MainThread) [custom_components.sat.config_flow] Discovered MQTT at [mqtt://ems-esp/heartbeat]

2025-12-29 15:30:50.808 DEBUG (MainThread) [custom_components.sat.config_flow] Identified gateway type ems: ems-esp

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🔗 Similar Issues

Related Issues

• EvoHome - Rooms do not reach set temperatures #80
• Boiler runs uncontrolled for hours due to SAT low setpoint behavior #131
• ESPHome max_modulation_level always set to 0 #59
• Keeps requesting heat for rooms with closed trv's #122
• Calibrating and finding overshoot value times out waiting for heating system to start on v4 #77
• EMS-ESP Unloads shortly after changing to Heat mode #110
• Modulation and Setpoint Synchro report alternating problems based on BoilerStatus #113
• Error unloading entry logs #118
• SAT climate integration not responding to changes on TRV #105

🔗 Related PRs

#69 - Improved the dynamic minimum setpoint [merged]
#72 - Spoiler alert: New Years Eve Release [merged]
#81 - Improved static typing [merged]
#83 - Connected Thermostat [merged]

👤 Suggested Assignees

• Alexwijn
• Rick-van-Dam
• user34756361233
• pi-ter
• clau-bucur

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[sergeantd83]

Hi! Try to reload SAT integration.

[sergimola]

Hi! Try to reload SAT integration.

Is there a way to completely remove the integration configuration and start from scratch?
I've tried reloading it several times and it had no effect.