IVT Rego 5101 Installation Manual page 33

5.6.19 Communication error with accessory x (B)
Function: E21 has lost contact with the stated
accessory.
Heat pump: E21.
B Check the physical address of the accessory.
B Check the settings for the accessory in E21
( Table 37, page 21).
B Check the connections between E21 and the
accessory.
B Check the communication cable regarding laying (at
least 100 mm distance to power cables) and any
damage.
B Check the power supply.
B Terminate communication cable at each end as
necessary (use a resistor of 120 Ω, 0.5 W).
5.6.20 Problem with hot water production (B)
Function: During previous hot water production, T3 was
still below its start limit when T9 interrupted production
because of risk of High temperature T9. Hot water
production is stopped. The alarm cannot appear if
Failure on sensor T3 is present. Automatic resetting
occurs at midnight.
Heat pump: Heat pump with T3 as local sensor.
B Check the hot water system.
B Check that T3 and T9 show correct temperature,
compare with resistance table.
B Check that the installation is correctly dimensioned.
5.6.21 Problem with Q21 3-way valve (B)
Problem with E4x.Q1x 3-way valve (B)
Function: Hot water production stops because E11.T1 is
10 K above the set point and has increased by 15 K
during hot water mode
The values can be set in Installer level under Hot
water\Settings\Heat protection.
Heat pump: Heat pump with T3 as local sensor.
B Check that the valve can operate and is correctly
connected.
B Check that the system is correctly connected.
B Check that the valve does not leak.
B Check that E11. T1 shows correct temperature,
compare with resistance table.
6 720 645 172 (2010/07) en
5.6.22 Start-up attempt interrupted (B)
Function: At compressor start the temperatures and
pressure switches are checked. When one of these is not
approved by the control unit the start attempt is
cancelled. A new start attempt occurs after 20 min if a
demand arises.
Activated when the corresponding category C-alarm has
occurred more than once during the last 120 minutes.
Heat pump: All.
B Check the cause using the temperature log and alarm
history ( Table 46, page 27).
5.6.23 Check phase sequence and T6 (B)
Function: The compressor is stopped. Activated if the
hot gas temperature T6 does not exceed T8 heat transfer
fluid out by 10 K within 3 min of compressor start. E21:
Additional heat permitted to start.
Heat pump: All.
At commissioning/During operation:
B Check the direction of rotation of the compressor.
B Check the incoming phase sequence.
B Check that sensors T6 and T8 show the correct
temperature, compare with resistance table.
B Check the connections to the sensors.
B Check the refrigerant circuit.
5.6.24 Internal add. heat overheated (B)
Function: Additional heat operation is stopped.
Overheat protection on the internal additional heat has
tripped.
Heat pump: E21 with internal electric additional heat.
B Reset the overheat protection on the electric
additional heater.
B Check the function of heat carrier pump G2.
B Clean the heating system particle filter if necessary.
B Check the flow in the heating system.
B Check the valves in the heating system.
5.6.25 External add. heat out of order (B)
Function: The additional heat mixing valve is closed. No
signal from the external additional heat thermostat
indicating sufficient heat.
Heat pump: E21 with external additional heat.
B Check that the additional heat is running and has
sufficient temperature.
B Check thermostat E71.E1.B31 and connections.
Information/Alarms
33