Bosch EasyControl on a Nefit or Bosch boiler: which series work directly, which with an adapter

Short answer: on the Nefit series TrendLine, ProLine, TopLine, BaseLine, SmartLine, 9000i, 2300i and 1200 and on Bosch HRC II, HRS II, Compact, Condens 3000W and 6000W you connect the EasyControl directly directly to the EMS bus. For the older Nefit ProLine NxT, EcomLine and Economy (iRT protocol) and for Bosch HRC I, HRC Top and HRS Top you need the EasyControl Adapter . This is Bosch's own list (brochure October 2024).

Nefit by series

Nefit series	Protocol	EasyControl	Parts and fault codes
TrendLine (I and II, AquaPower Plus)	EMS	Direct	TrendLine parts
ProLine (HRC, without NxT)	EMS	Direct	ProLine parts
ProLine NxT	iRT	With adapter	ProLine NxT parts
TopLine (Compact, AquaPower, HR, HRC)	EMS	Direct	TopLine parts
BaseLine	EMS	Direct	Nefit spare parts
SmartLine	EMS	Direct	Nefit spare parts
9000i, 9700i, 2300i, 1200	EMS 2.0	Direct	Nefit spare parts
EcomLine (Excellent, Classic, Elite, Economy HRC 23V)	iRT	With adapter	EcomLine parts
Economy HR, Turbo HR	iRT or on/off	With adapter	Nefit spare parts
EnviLine (air source heat pump)	EMS	Direct	Nefit spare parts

All Nefit fault codes with cause and part: Nefit fault codes.

Bosch by series

Bosch series	EasyControl	Comment
HRC II, HRS II	Direct	EMS bus
Compact, Condens 3000W, Condens 6000W	Direct	EMS bus
HRC I, HRC Top, HRS Top	With adapter	Only if the OTM1 module is fitted in the boiler; your installer can check this
Compress 3400i AWS, Compress 5800i AW hybride (warmtepomp)	Direct	Supported since app version 4.2.2

Bosch parts and codes: Bosch parts, Bosch fault codes.

Zo ziet u welke Nefit u hebt

The series name is on the rating plate behind or under the front cover (for example "TrendLine HRC 25/CW4" or "EcomLine HR 22"). If it says "NxT" after ProLine, it is the iRT version and you need the adapter. If a Nefit ModuLine Easy or Easy Connect module is currently attached to the boiler, it has to be removed.

What you need (EMS bus: just the thermostat)

Older Nefit (iRT) or Bosch HRC I/Top: thermostat with adapter

Step by step: connecting EasyControl

Always read your boiler's installation manual first. If you are unsure about the terminals, have an installer do it.

1. Disconnect the boiler from the power (unplug it) and disconnect the existing thermostat. Bosch specifies that only one thermostat may be connected to the boiler.
2. Connect the EasyControl with two wires to the boiler's EMS bus terminals (no polarity, no terminating resistor needed).
3. Switch the boiler on, connect to your 2.4 GHz Wi-Fi via the Bosch EasyControl app (5 GHz does not work) and follow the setup.
4. After half an hour, check whether the boiler modulates (the flame keeps burning at lower output) and whether the app shows the boiler status.

Do you have an iRT boiler (ProLine NxT, EcomLine, Economy)? Then the adapter goes between the boiler and the thermostat, with its own power socket; the switch-on sequence is described in the general guide.

Things to bear in mind

• On/off via the adapter: the boiler does not modulate and the app reads nothing (no water pressure, no consumption). You do keep remote control, the time programme and presence detection.
• OpenTherm via the adapter: modulating. The water pressure is only shown if the boiler has a pressure sensor and the values have been checked once.
• Nefit Easy Connect or RCC module on an older boiler: remove it first, EasyControl does not work together with it.
• One EasyControl per boiler. You control multiple rooms with the Smart Radiator Thermostats (radiator heads), not with a second thermostat.
• 2.4 GHz Wi-Fi is required; a network that only broadcasts 5 GHz does not work.

Frequently asked questions

Does the EasyControl fit a Nefit TrendLine HRC 25/CW4?

Yes, directly on the EMS bus terminals. You do not need an adapter; the app shows water pressure and consumption.

Does the EasyControl fit a Nefit ProLine NxT?

Only with the EasyControl Adapter. The ProLine NxT uses the older iRT protocol. The newer ProLine without NxT has EMS and works directly.

My Nefit EcomLine has a ModuLine thermostat. Can I switch?

Yes, with the EasyControl Adapter. Disconnect the ModuLine and, if fitted, the Easy Connect module as well. The adapter converts the iRT signal.

Can I combine Bosch radiator thermostats with an older Nefit?

Yes. The Smart Radiator Thermostats talk wirelessly to the EasyControl, not to the boiler. So they also work when the boiler is connected via the adapter.

Does the app show the water pressure on every Nefit?

On EMS boilers, yes. With a connection via the adapter, only if the boiler has a pressure sensor and the values have been verified.

Other brands

• Overview of all brands: does EasyControl fit my boiler?
• EasyControl on an Intergas boiler
• EasyControl on a Remeha boiler
• EasyControl on an ATAG boiler
• EasyControl on a Vaillant boiler

Sources: Bosch brochure "Is EasyControl geschikt voor mijn verwarmingssysteem?" (document number 6721867369, October 2024) and the page about the EasyControl Adapter on nefit-bosch.nl. Protocols of other brands: manufacturers' installation manuals. Page updated: 12 October 2026.