Hoval TopTronic E Heat Generator

Name: Hoval TopTronic E Heat Generator
Brand: Hoval
SKU: c9f7a397-c304-48d6-a1f4-5f2a992e304a

Controller of Hoval boilers and heat pumps with temperatures, output, energy, status and setpoints over Modbus TCP.

The Hoval TopTronic E Heat Generator is the basic controller module that runs Hoval boilers and heat pumps with their heating circuits and hot water in buildings, commercial boiler plants and greenhouses. This Modbus TCP template reads temperatures, modulation, power, energy counters, status and error codes through the Hoval Modbus gateway and writes operating modes and setpoints from ModbusCloud.

Protocol: Modbus TCP
Connection: Ethernet, Modbus TCP
Registers: 352, read and write

Brand: Hoval
Key readings: Flow and return temperature · Modulation · Heating and electrical power · Water pressure · Operating hours and switching cycles · Heat quantity and electrical energy · Outdoor temperature · Status and error code
Available commands: Heat generator operation choice · Manual mode set temperature · Manual mode output setpoint · Heating circuit room setpoints · Hot water setpoint · Smart Grid and power limitation
Compatible models: TopTronic E basic module heat generator (WEZ) · Hoval gas and pellet boilers with TopTronic E · Hoval heat pumps with TopTronic E (WFA-200 or ECR461 controller)
Last updated: 7 October 2026

Registers (352)

352 read, 113 write

Name	Unit	Access
Heat Generator Flow Temperature	°C	Read
Heat Generator Return Temperature	°C	Read
Heat Generator Flow Setpoint	°C	Read
Heat Generator Modulation	%	Read
Heat Generator Electrical Power	kW	Read
Heat Generator Heating Power	kW	Read
Heat Generator Current Output Heating	kW	Read
Heat Generator Current Output Cooling	kW	Read
Heat Generator Water Pressure	bar	Read
Heat Generator Volume Flow	l/min	Read
Heat Generator Main Pump Speed	%	Read
Heat Generator Ionisation		Read
Heat Generator Total Energy Efficiency		Read
FA Setpoint Heating Circuit Operation	°C	Read
FA Setpoint Tank Operation	°C	Read
FA Output Limitation	%	Read
FA Setpoint Cooling Mode	°C	Read
FA Heat Generator Temperature	°C	Read
FA Exhaust Gas Temperature	°C	Read
FA Switching Temperature Active/Passive	°C	Read
FA Heating Setpoint	°C	Read
FA Storage Tank Setpoint	°C	Read
FA Heat Generator Setpoint	°C	Read
FA Heating External Maximum Limit	°C	Read
FA Tank External Maximum Limit	°C	Read
FA Return Temperature	°C	Read
FA Heat Generator Output	%	Read
FA Absolute Output	%	Read
FA Water Pressure	bar	Read
FA Cooling Setpoint	°C	Read
FA COP		Read
FA Probe Flow/Intake Temperature	°C	Read
FA Probe Return/Evaporator Temperature	°C	Read
Outdoor Temperature AF1	°C	Read
Outdoor Temperature AF2	°C	Read
System Flow Temperature Heating	°C	Read
System Flow Temperature Hot Water	°C	Read
System Flow Temperature Cooling	°C	Read
System Temperature Setpoint Heating	°C	Read
System Temperature Setpoint Hot Water	°C	Read
System Temperature Setpoint Cooling	°C	Read
System Output Setpoint Heating	%	Read
System Output Setpoint Hot Water	%	Read
System Output Setpoint Cooling	%	Read
Heating Circuit 1 Room Temperature	°C	Read and write
Heating Circuit 1 Flow Temperature	°C	Read
Heating Circuit 1 Return Temperature	°C	Read
Heating Circuit 1 Room Setpoint	°C	Read
Heating Circuit 1 Flow Setpoint	°C	Read
Heating Circuit 2 Room Temperature	°C	Read and write
Heating Circuit 2 Flow Temperature	°C	Read
Heating Circuit 2 Return Temperature	°C	Read
Heating Circuit 2 Room Setpoint	°C	Read
Heating Circuit 2 Flow Setpoint	°C	Read
Heating Circuit 3 Room Temperature	°C	Read and write
Heating Circuit 3 Flow Temperature	°C	Read
Heating Circuit 3 Return Temperature	°C	Read
Heating Circuit 3 Room Setpoint	°C	Read
Heating Circuit 3 Flow Setpoint	°C	Read
Hot Water Temperature SF	°C	Read
Hot Water Temperature SF2	°C	Read
Circulation Temperature	°C	Read
Hot Water Setpoint	°C	Read
Global Radiation	W/m²	Read
Plant Flow Temperature FAV	°C	Read
Plant Flow Setpoint FAV	°C	Read
Info Sensor 1	°C	Read
Info Sensor 2	°C	Read
Info Sensor 3	°C	Read
Info Sensor 4	°C	Read
Info Sensor 5	°C	Read
Info 1 0-10V		Read
Info 2 0-10V		Read
Info 3 0-10V		Read
Cascade 1 Output Setpoint	%	Read
Cascade 1 Current Demand	%	Read
Cascade 2 Output Setpoint	%	Read
Cascade 2 Current Demand	%	Read
Cascade 3 Output Setpoint	%	Read
Cascade 3 Current Demand	%	Read
Cascade 4 Output Setpoint	%	Read
Cascade 4 Current Demand	%	Read
Cascade 5 Output Setpoint	%	Read
Cascade 5 Current Demand	%	Read
Cascade 6 Output Setpoint	%	Read
Cascade 6 Current Demand	%	Read
Cascade 7 Output Setpoint	%	Read
Cascade 7 Current Demand	%	Read
Cascade 8 Output Setpoint	%	Read
Cascade 8 Current Demand	%	Read
Additional Heat Flow Temperature	°C	Read
Additional Heat Return Temperature	°C	Read
Additional Heat Flow Setpoint	°C	Read
Additional Heat Current Output Heating	kW	Read
Additional Heat Volume Flow	l/min	Read
Additional Heat Main Pump Speed	%	Read
Additional Heat Output Setpoint	%	Read
WFA Buffer Sensor WPF	°C	Read
WFA CP Speed	%	Read
WFA CP Speed (Duplicate)		Read
WFA Heat Source Pump Speed	%	Read
WFA Heat Source Pump Speed (Duplicate)	%	Read
WFA GWP		Read
WFA Ground Water Temperature	°C	Read
WFA Ground Water Temperature (Duplicate)	°C	Read
WFA Volume Flow Averaged	l/min	Read
WFA GWP Speed	%	Read
WFA HP Flow Temperature	°C	Read
WFA HP Return Temperature	°C	Read
WFA Primary Flow Temperature	°C	Read
WFA Primary Return Temperature	°C	Read
WFA Intake Air Temperature 1	°C	Read
WFA Suction Gas Temperature 1	°C	Read
WFA Hot Gas Temperature 1	°C	Read
WFA Overheating 1	K	Read
WFA Low Pressure 1	bar	Read
WFA High Pressure 1	bar	Read
WFA Actual Speed	%	Read
ECR Primary Flow Temperature 1	°C	Read
ECR Primary Return Temperature 1	°C	Read
ECR Ground Water Temperature	°C	Read
ECR Current COP		Read
Heat Generator Pump	%	Read
Heat Generator Status		Read
Heat Generator FA Status		Read
Heat Generator Operating Message		Read
FA Emission Measurement		Read
FA Burner Flame		Read
FA Error Code		Read
FA Heat Generator Status		Read
FA Operating Status		Read
FA Status Information		Read
Cooling Valve Active UKA		Read
Cooling Valve General UHKA		Read
Heating Circuit 1 Pump		Read
Heating Circuit 1 Mixer	%	Read
Heating Circuit 1 Status		Read
Heating Circuit 2 Pump		Read
Heating Circuit 2 Mixer	%	Read
Heating Circuit 2 Status		Read
Heating Circuit 3 Pump		Read
Heating Circuit 3 Mixer	%	Read
Heating Circuit 3 Status		Read
Hot Water Circulation Pump		Read
Hot Water Charging Pump		Read
Hot Water Status		Read
Collective Fault Output		Read
AVP Pump		Read
YAV Mixer	%	Read
Smart Grid Status		Read
Smart Grid Status (Duplicate)		Read
Setpoint Increase/Decrease Status		Read
Cascade 1 Lead Heat Generator		Read
Additional Heat Pump	%	Read
Additional Heat Burner Stage		Read
Additional Heat Status		Read
WFA High Pressure 1 Fault		Read
Heat Generator Operation Choice		Read and write
Heat Generator Manual Mode Set Temperature	°C	Read and write
Heat Generator Manual Mode Output Setpoint	%	Read and write
Heat Generator Temperature Increase	K	Read and write
Heat Generator Emissions Test Active		Read and write
Heat Generator Emissions Test Output Limit	%	Read and write
Heating Circuit 1 Operation Choice		Read and write
Heating Circuit 1 Normal Room Temperature Heating	°C	Read and write
Heating Circuit 1 Eco Room Temperature Heating	°C	Read and write
Heating Circuit 1 Normal Room Temperature Cooling	°C	Read and write
Heating Circuit 1 Eco Room Temperature Cooling	°C	Read and write
Heating Circuit 1 Manual Mode Set Temperature	°C	Read and write
Heating Circuit 1 Manual Mode Set Temperature (Duplicate)	°C	Read and write
Heating Circuit 1 Constant Flow Setpoint Heating	°C	Read and write
Heating Circuit 1 Constant Flow Setpoint Cooling	°C	Read and write
Heating Circuit 1 Smart Grid Room Offset Heating	K	Read and write
Heating Circuit 1 Smart Grid Room Offset Cooling	K	Read and write
Heating Circuit 2 Operation Choice		Read and write
Heating Circuit 2 Normal Room Temperature Heating	°C	Read and write
Heating Circuit 2 Eco Room Temperature Heating	°C	Read and write
Heating Circuit 2 Normal Room Temperature Cooling	°C	Read and write
Heating Circuit 2 Eco Room Temperature Cooling	°C	Read and write
Heating Circuit 2 Manual Mode Set Temperature	°C	Read and write
Heating Circuit 2 Manual Mode Set Temperature (Duplicate)	°C	Read and write
Heating Circuit 2 Constant Flow Setpoint Heating	°C	Read and write
Heating Circuit 2 Constant Flow Setpoint Cooling	°C	Read and write
Heating Circuit 2 Smart Grid Room Offset Heating	K	Read and write
Heating Circuit 2 Smart Grid Room Offset Cooling	K	Read and write
Heating Circuit 3 Operation Choice		Read and write
Heating Circuit 3 Normal Room Temperature Heating	°C	Read and write
Heating Circuit 3 Eco Room Temperature Heating	°C	Read and write
Heating Circuit 3 Normal Room Temperature Cooling	°C	Read and write
Heating Circuit 3 Eco Room Temperature Cooling	°C	Read and write
Heating Circuit 3 Manual Mode Set Temperature	°C	Read and write
Heating Circuit 3 Manual Mode Set Temperature (Duplicate)	°C	Read and write
Heating Circuit 3 Constant Flow Setpoint Heating	°C	Read and write
Heating Circuit 3 Constant Flow Setpoint Cooling	°C	Read and write
Heating Circuit 3 Smart Grid Room Offset Heating	K	Read and write
Heating Circuit 3 Smart Grid Room Offset Cooling	K	Read and write
Hot Water Operation Choice		Read and write
Normal Hot Water Temperature	°C	Read and write
Eco Hot Water Temperature	°C	Read and write
Smart Grid Hot Water Offset	K	Read and write
Available Electrical Power	kW	Read and write
Available Electrical Power Dampened	kW	Read and write
Smart Grid via System Bus		Read and write
Smart Grid Function Trigger		Read and write
Additional Heat Operation Choice		Read and write
Additional Heat Manual Mode Set Temperature	°C	Read and write
Additional Heat Manual Mode Output Setpoint	%	Read and write
Additional Heat Temperature Increase	K	Read and write
WFA Power Limitation	kW	Read and write
WFA Power Limitation Function		Read and write
Heat Generator Max Output Heating	%	Read and write
Heat Generator Max Output Hot Water	%	Read and write
Heat Generator Max Output Cooling	%	Read and write
Heat Generator Release Outdoor Temperature	°C	Read and write
Heating Circuit 1 Heating Curve Base Flow Temperature	°C	Read and write
Heating Circuit 1 Heating Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 1 Heating Curve Design Flow Temperature	°C	Read and write
Heating Circuit 1 Control Strategy		Read and write
Heating Circuit 1 Cooling Curve Base Flow Temperature	°C	Read and write
Heating Circuit 1 Summer Compensation Start Point	°C	Read and write
Heating Circuit 1 Cooling Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 1 Cooling Curve Design Flow Temperature	°C	Read and write
Heating Circuit 1 Heat Generator Flow Setpoint Offset	°C	Read and write
Heating Circuit 1 Minimum Flow Temperature	°C	Read and write
Heating Circuit 1 Maximum Flow Temperature	°C	Read and write
Heating Circuit 1 Minimum Flow Temperature Cooling	°C	Read and write
Heating Circuit 2 Heating Curve Base Flow Temperature	°C	Read and write
Heating Circuit 2 Heating Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 2 Heating Curve Design Flow Temperature	°C	Read and write
Heating Circuit 2 Control Strategy		Read and write
Heating Circuit 2 Cooling Curve Base Flow Temperature	°C	Read and write
Heating Circuit 2 Summer Compensation Start Point	°C	Read and write
Heating Circuit 2 Cooling Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 2 Cooling Curve Design Flow Temperature	°C	Read and write
Heating Circuit 2 Heat Generator Flow Setpoint Offset	°C	Read and write
Heating Circuit 2 Minimum Flow Temperature	°C	Read and write
Heating Circuit 2 Maximum Flow Temperature	°C	Read and write
Heating Circuit 2 Minimum Flow Temperature Cooling	°C	Read and write
Heating Circuit 3 Heating Curve Base Flow Temperature	°C	Read and write
Heating Circuit 3 Heating Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 3 Heating Curve Design Flow Temperature	°C	Read and write
Heating Circuit 3 Control Strategy		Read and write
Heating Circuit 3 Cooling Curve Base Flow Temperature	°C	Read and write
Heating Circuit 3 Summer Compensation Start Point	°C	Read and write
Heating Circuit 3 Cooling Curve Design Outdoor Temperature	°C	Read and write
Heating Circuit 3 Cooling Curve Design Flow Temperature	°C	Read and write
Heating Circuit 3 Heat Generator Flow Setpoint Offset	°C	Read and write
Heating Circuit 3 Minimum Flow Temperature	°C	Read and write
Heating Circuit 3 Maximum Flow Temperature	°C	Read and write
Heating Circuit 3 Minimum Flow Temperature Cooling	°C	Read and write
Available Power Source		Read and write
Dampened Power Source		Read and write
Dampened Power Time Filter	min	Read and write
Smart Grid Minimum Power	kW	Read and write
SG Forced Acceptance Threshold	kW	Read and write
SG Forced Acceptance Hysteresis	kW	Read and write
SG Preferential Operation Threshold	kW	Read and write
SG Preferential Operation Hysteresis	kW	Read and write
Available Power Offset	kW	Read and write
Available Power Dampened Offset	kW	Read and write
SG Minimum Power Hysteresis	kW	Read and write
Cascade 1 Sequence Change Time		Read and write
Heat Generator Operating Hours (Duplicate)	h	Read
Heat Generator Operating Hours	h	Read
Heat Generator Switching Cycles		Read
Heat Generator Operating Hours Above 50%	h	Read
Heat Generator Switching Cycles Above 50%		Read
Heat Generator Heat Quantity Heating	MWh	Read
Heat Generator Cooling Quantity	MWh	Read
Heat Generator Electrical Energy	MWh	Read
FA Heat Quantity Heating	MWh	Read
FA Heat Quantity Cooling	MWh	Read
FA Heat Quantity Hot Water	MWh	Read
Additional Heat Operating Hours	h	Read
Additional Heat Switching Cycles		Read
Additional Heat Heat Quantity Heating	MWh	Read
WFA Heating Running Time	h	Read
WFA Cooling Running Time	h	Read
WFA Hot Water Running Time	h	Read
ECR Additional Heating Operating Hours	h	Read
ECR Additional Heating Starts		Read
ECR Heating Operating Hours	h	Read
ECR Hot Water Operating Hours	h	Read
ECR Active Cooling Operating Hours	h	Read
FA Burner ID Index		Read
FA Function Extensions		Read
MK1 Output		Read and write
YK1+ Output		Read and write
YK1- Output		Read and write
DKP Output		Read and write
SLP Output		Read and write
VA1 Output		Read
VA2 Output		Read
VA1-FE1 Output		Read
VA2-FE1 Output		Read
VA3-FE1 Output		Read
VA1-FE2 Output		Read
VA2-FE2 Output		Read
VA3-FE2 Output		Read
VA 0-10V/PWM Output	%	Read
VA 0-10V/PWM FE1 Output	%	Read
Relay Test Active		Read
WFA Application Number		Read
ECR Output Y1 0-10V/PWM	%	Read
ECR Output Y2 0-10V/PWM	%	Read
ECR Relay Output R9		Read
ECR Relay Output R152		Read
Active Error 1 Appearance Time		Read
Active Error 1 Appearance Date		Read
Active Error 1 Disappear Time		Read
Active Error 1 Disappear Date		Read
Active Error 1 Source		Read
Active Error 1 Function Group		Read
Active Error 1 Function Number		Read
Active Error 1 Error Type		Read
Active Error 1 Error Code		Read
Active Error 2 Appearance Time		Read
Active Error 2 Appearance Date		Read
Active Error 2 Disappear Time		Read
Active Error 2 Disappear Date		Read
Active Error 2 Source		Read
Active Error 2 Function Group		Read
Active Error 2 Function Number		Read
Active Error 2 Error Type		Read
Active Error 2 Error Code		Read
Active Error 3 Appearance Time		Read
Active Error 3 Appearance Date		Read
Active Error 3 Disappear Time		Read
Active Error 3 Disappear Date		Read
Active Error 3 Source		Read
Active Error 3 Function Group		Read
Active Error 3 Function Number		Read
Active Error 3 Error Type		Read
Active Error 3 Error Code		Read
Active Error 4 Appearance Time		Read
Active Error 4 Appearance Date		Read
Active Error 4 Disappear Time		Read
Active Error 4 Disappear Date		Read
Active Error 4 Source		Read
Active Error 4 Function Group		Read
Active Error 4 Function Number		Read
Active Error 4 Error Type		Read
Active Error 4 Error Code		Read
Active Error 5 Appearance Time		Read
Active Error 5 Appearance Date		Read
Active Error 5 Disappear Time		Read
Active Error 5 Disappear Date		Read
Active Error 5 Source		Read
Active Error 5 Function Group		Read
Active Error 5 Function Number		Read
Active Error 5 Error Type		Read
Active Error 5 Error Code		Read

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If a device is not in the library yet, we build the template for free as soon as we have the register data.

Use cases

Put flow, return and outdoor temperature, modulation and output of the boiler or heat pump on one dashboard for the boiler house.
Get an email, in-app or webhook alert when the heat generator status goes to fault or the error code changes.
Track operating hours, switching cycles and heat quantity over 365 days to plan maintenance and spot short cycling.
Change the operating mode and room or hot water setpoints remotely once writing is enabled for the gateway.
Write the available electrical power or the Smart Grid state from an automation on an energy price or a time schedule.

Installation

Connect the Hoval Modbus gateway of the TopTronic E system to the same network as the ModbusCloud Gateway and give it a fixed IP address.
Check on the TopTronic E operating module that the heat generator has module address 1. Another address uses other register addresses.
In ModbusCloud, add a Modbus device with Modbus TCP, the IP address of the Hoval gateway, port 502 and unit ID 1, then import this template.
Check that Outdoor Temperature AF1 and Heat Generator Flow Temperature show plausible values. Functions that are not installed may not answer.
Keep the reading interval at the default 5 minutes. Hoval advises longer intervals as the number of requests to its gateway grows.

Things to watch for

The Hoval gateway does not answer. What should I check?

Check that the ModbusCloud Gateway reaches the IP address of the Hoval Modbus gateway, and use port 502 and unit ID 1. The Hoval gateway has to be registered in the HovalConnect app, which also keeps its software up to date. Data points of functions or modules that are not installed can time out, for example the SF2 hot water sensor when it is not fitted.

How do I read a second heat generator or a cascade?

Every heat generator has its own module address from 1 to 16 on the TopTronic E bus, shown on the operating module. Hoval gives each data point of each module address its own register address, with no fixed offset. This template is for address 1. For heat generator 2, make your own template in ModbusCloud with the addresses Hoval lists for WEZ UnitId 2 in its Modbus data point list.

Why does a setpoint I write have no effect?

Writing is off per gateway until you request it in the portal. Room setpoints only apply when Operation Choice of the heating circuit is 4 (constant), and hot water works the same way. Constant flow setpoints, manual heat generator modes and Smart Grid need basic settings by Hoval service first. A written value stays active until a new one is written.

How often should ModbusCloud read the Hoval gateway?

The default of every 5 minutes is a good choice. Hoval warns that its Modbus gateway can lock up when it gets too many requests. This template has many registers. If you only need a few values, make your own template with just those registers.

Why do some registers not answer on my boiler?

The template holds the values of every heat generator type, including the heat pump controllers WFA-200 and ECR461 and the cascade manager. On a boiler without those functions these data points can time out or show no useful value. Leave them off your dashboards or out of your own template.

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