diff --git a/succbone/succd/modbus.go b/succbone/succd/modbus.go
index a4d05e0..e5f3b91 100644
--- a/succbone/succd/modbus.go
+++ b/succbone/succd/modbus.go
@@ -2,10 +2,11 @@ package main
 
 import (
 	"context"
+	"errors"
+	"fmt"
 	"time"
 
 	"github.com/simonvetter/modbus"
-	"k8s.io/klog"
 )
 
 func modbusValuesToFloat(v uint16) float32 {
@@ -38,7 +39,7 @@ func (d *daemon) modbusConnect() error {
 // There are currently two devices connected to the modbus.
 // The first one (slave 1) is a temperature/humidity sensor.
 // The second one (slave 2) is a PTA8D08 transmitter
-func (d *daemon) modbusUpdate() {
+func (d *daemon) modbusUpdate() error {
 	var err error
 
 	// Switch to slave 1 (BTA1)
@@ -48,16 +49,19 @@ func (d *daemon) modbusUpdate() {
 	var registersBTA1 []uint16 // temperature, humidity
 	registersBTA1, err = d.modbusClient.ReadRegisters(1, 2, modbus.INPUT_REGISTER)
 	if err != nil {
-		klog.Warningf("error while reading registers from BTA1 %v", err)
-	} else if len(registersBTA1) != 2 {
-		klog.Warningf("expected two registers from modbus slave 1, but got %d", len(registersBTA1))
-	} else {
-		d.mu.Lock()
-		d.daemonState.tempSEM = modbusValuesToFloat(registersBTA1[0])
-		d.daemonState.humiditySEM = modbusValuesToFloat(registersBTA1[1])
-		d.mu.Unlock()
+		return err
 	}
 
+	if len(registersBTA1) != 2 {
+		msg := fmt.Sprintf("Expected two registers from modbus slave 1, but got %d", len(registersBTA1))
+		return errors.New(msg)
+	}
+
+	d.mu.Lock()
+	d.daemonState.tempSEM = modbusValuesToFloat(registersBTA1[0])
+	d.daemonState.humiditySEM = modbusValuesToFloat(registersBTA1[1])
+	d.mu.Unlock()
+
 	// Switch to slave 2 (KEC2)
 	d.modbusClient.SetUnitId(2)
 
@@ -68,17 +72,19 @@ func (d *daemon) modbusUpdate() {
 	var registersKEC2 []uint16 // temperatures dp
 	registersKEC2, err = d.modbusClient.ReadRegisters(0, 3, modbus.HOLDING_REGISTER)
 	if err != nil {
-		klog.Warningf("error while reading registers from KEC2 %v", err)
-	} else if len(registersKEC2) != 3 {
-		klog.Warningf("expected three registers from modbus slave 2, but got %d", len(registersKEC2))
-	} else {
-		d.mu.Lock()
-		d.daemonState.tempDPBottom = modbusValuesToFloat(registersKEC2[0])
-		d.daemonState.tempDPInlet = modbusValuesToFloat(registersKEC2[1])
-		d.daemonState.tempDPTop = modbusValuesToFloat(registersKEC2[2])
-		d.mu.Unlock()
+		return err
 	}
 
+	if len(registersKEC2) != 3 {
+		return fmt.Errorf("expected three registers from modbus slave 2, but got %d", len(registersKEC2))
+	}
+
+	d.mu.Lock()
+	d.daemonState.tempDPBottom = modbusValuesToFloat(registersKEC2[0])
+	d.daemonState.tempDPInlet = modbusValuesToFloat(registersKEC2[1])
+	d.daemonState.tempDPTop = modbusValuesToFloat(registersKEC2[2])
+	d.mu.Unlock()
+
 	// Switch to slave 3 (KEC1)
 	d.modbusClient.SetUnitId(3)
 
@@ -88,18 +94,17 @@ func (d *daemon) modbusUpdate() {
 
 	digitalInputRegisters, err = d.modbusClient.ReadRegisters(0x81, 8, modbus.HOLDING_REGISTER)
 	if err != nil {
-		klog.Warningf("error while reading digital inputs from KEC1 %v", err)
-	} else {
-		// Convert MODBUS words into bools
-		for idx, value := range digitalInputRegisters {
-			if value != 0 {
-				digitalInputs[idx] = true
-			} else {
-				digitalInputs[idx] = false
-			}
-		}
-		// TODO: Input mapping goes here
+		return err
 	}
+	// Convert MODBUS words into bools
+	for idx, value := range digitalInputRegisters {
+		if value != 0 {
+			digitalInputs[idx] = true
+		} else {
+			digitalInputs[idx] = false
+		}
+	}
+	// TODO: Input mapping goes here
 
 	// KFA1-KFA8
 	var relayState [8]bool
@@ -135,8 +140,10 @@ func (d *daemon) modbusUpdate() {
 
 	err = d.modbusClient.WriteRegisters(0x01, registerValuesKEC1[:])
 	if err != nil {
-		klog.Warningf("error while updating registers %v", err)
+		return err
 	}
+
+	return nil
 }
 
 // Call modbusUpdate every 100 milliseconds