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Nilan

Nilan CTS400 / ES1077 (Comfort 250 Top)

Thermostats · Climate

Partly worksLocal

2 reports: 1 says it partly works, 1 asks for support.

Reported with 2 integrations: Genvex Connect, Nilan.

What people report

IntegrationIn Home AssistantIn Apple HomeWhat they saidSource
Genvex ConnectPartly works LocalSensor addresses reportedly differ from other Nilan libraries; values mismatch app
Saved copy
It seems like the addresses in the GenvexNabtoCTS400 for the sensors does not match the addresses in the other Nilan libraries. From what i can find, ex. https://github.com/nic6911/ESP32_Modbus_Module/blob/main/esphome_example_code/Nilan_cts400.yaml has the addresses that matches my test results (image placed last in this comment)

Excerpt saved from GitHub on 2026-10-23.

Issue #7 · 2024-08
NilanRequested LocalDifferent register map; support PR open
Saved copy
Why Adds support for the Nilan CTS400 / ES1077 controller (Comfort 250 Top) alongside the existing CTS602 integration. The CTS400 uses a different Modbus register space, cannot be auto-detected (it has no CTS602 `control_type` register at holding 1000), and only supports function codes FC03/FC04/FC06. It therefore can't be added as a small CTS602 "device key" and is wired as a distinct board family. This is ready for review, opened from a fork, and refs discussion #165. It is additive only - no CTS602 behavior changes. ## Provenance and verification - Verified live on a Nilan Comfort 250 Top …

Excerpt saved from GitHub on 2026-10-23.

PR #223 · 2026-06

Each row is one report from a GitHub thread, an integration’s docs, or r/homeassistant. Check the date and the linked source before you buy.

In ReReHome

Once Home Assistant’s HomeKit Bridge shares it, this device reaches Apple Home as a HomeKit accessory behind your Home Assistant bridge, so ReReHome shows and controls it like any other.

Identifiers

BrandNilan
ModelCTS400
CategoryThermostats

Also reported as

  • Nilan CTS400 ventilation unit