Daikin Altherma 3 H HT ETVH16S18E6V7

Compatibility

Compatible for read-only monitoring through DCOM-LT/MB

Daikin's ETVH16-E7 combination table lists EPRA14DV37 and DCOM-LT/MB for this exact indoor variant. Daikin's DCOM-LT/MB manual documents the P1P2-to-Modbus RTU interface and its read-only input-register map.

Confirm the ETVH16S18E6V7 and EPRA14DV37 nameplates, compatible Altherma LT master controller, fitted DCOM-LT/MB, P1P2 ownership, DCOM operating mode and available inputs. Do not substitute the older non-E7 ETVH16UE6V or assume a Daikin HomeHub EKRHH configuration shares this register map.

Connect it with

• 
  Modbus Interface ZMB-3X
  From €399 ex VAT Configure Modbus Interface
• 
  Gateway ZGW-20
  From €899 ex VAT Configure Gateway

Models

Specifications

The Daikin combination table names the ETVH16S18E6V7 indoor unit, EPRA14DV37 outdoor unit and DCOM-LT/MB accessory. This exact E7 suffix matters: a similarly named older indoor variant is not the same interface case.¹

System identity

ETVH16S18E6V7 indoor plus EPRA14DV37 outdoor, as listed in the combination table¹

Interface accessory

DCOM-LT/MB on compatible controller P1P2; separate 15–24 VDC supply^1, 2

Field bus

Two-wire EIA-485 Modbus RTU, 9600 baud, 8 data bits, one stop bit; DCOM is the slave²

Worked read

FC04, zero-based input offset 31: compressor run, 0 off or 1 on, in standard mode²

Temperature decode

FC04 input offset 42: signed 16-bit return-water temperature divided by 100 °C, in standard mode²

Invalid values

32767 unsupported; 32766 unavailable; 32765 waiting for value²

Performance boundary

Independent heat and electricity meters are needed for measured COP or SPF²

Interface

Documented measurements and integration boundaries for Altherma 3 H HT ETVH16S18E6V7.

• In the manual's standard mode, FC04 input offset 31 reports compressor run and offset 32 reports booster-heater run. Confirm each against the installed controller before accepting a point.
• Standard-mode input offsets 40 and 42 report leaving-water and return-water temperatures. Decode signed temp16 values as degrees Celsius divided by 100; validate them against the controller display.
• The DCOM manual uses zero-based register offsets, not 3xxxx labels. Unsupported, unavailable and waiting values are 32767, 32766 and 32765 and must not enter a temperature or energy calculation.
• Controller values do not establish delivered heat or whole-system COP. Independently meter thermal output and all electrical loads included in the chosen system boundary.
• No operation-mode, setpoint, DHW, weather compensation or smart-grid write is approved here. DCOM's writable holding registers remain under the commissioned heating controller.

Setup

1. Verify the installed pair

   Record the ETVH16S18E6V7 and EPRA14DV37 nameplates, indoor controller revision, installed accessories and site heating-control owner. Use Daikin's combination table for this exact E7 configuration.

2. Check the DCOM topology

   Confirm the fitted DCOM-LT/MB, its separate power supply, short P1P2 link to a compatible Altherma LT master and three-wire EIA-485 bus. Record its DIP-selected slave address and operating mode.

3. Commission a bounded read

   With the heating contractor present, read standard-mode FC04 input offset 31 for compressor state and offset 42 for return-water temperature. Confirm the client uses zero-based offsets, compare both with local operation and reject unavailable or waiting codes.

4. Measure performance separately

   Select the heat and electricity meter positions before reporting COP or SPF. Include pumps and auxiliary heaters when they fall inside the declared electrical boundary; align sampling periods.

Common questions

Does ETVH16S18E6V7 have a native Modbus port?

The documented path uses the separate DCOM-LT/MB accessory on a compatible controller's P1P2 connection. The DCOM is the Modbus RTU slave; do not connect Edge to the heat pump as if the outdoor unit were a Modbus server.^1, 2

Which DCOM registers are safe to read first?

In the manual's standard mode, FC04 offset 31 reports compressor run and offset 42 reports return-water temperature as signed hundredths of a degree Celsius. Check the DCOM mode and zero-based addressing, then compare the readings with local operation.²

Can the DCOM values prove heat-pump COP?

No. The DCOM map supplies controller operating values. Meter delivered heat and the chosen electrical boundary independently over the same periods before calculating COP or SPF.²