Operation; Overview: Operation; Heating; Domestic Hot Water - Daikin Altherma EHY2KOMB28AA Installation And Operation Manual

8 Operation

7 Put the front panel back in its place.
8 Operation
8.1

Overview: Operation

The gas boiler is a modulating, high-efficiency boiler. This means
that the power is adjusted in line with the desired heat requirement.
The aluminium heat exchanger has 2 separate copper circuits. As a
result of the separately constructed circuits for space heating and
domestic hot water, the heating and the hot water supply can
operate independently, but not simultaneously.
The gas boiler has an electronic boiler controller which does the
following when heating or hot water supply is required:
▪ starting the fan,
▪ opening the gas valve,
▪ igniting the burner,
▪ constantly monitoring and controlling the flame.
It is possible to use the domestic hot water circuit of the gas boiler
without connecting and filling the space heating system.
8.2

Heating

Heating is controlled by the outdoor unit. The boiler will start-up the
heating process when there is a request from the outdoor unit.
8.3

Domestic hot water

Not applicable for Switzerland
Instant domestic hot water is supplied by the boiler. When a
simultaneous demand of space heating and domestic hot water
occurs, domestic hot water has priority over space heating.
This manual only explains the domestic hot water making without
having a domestic hot water tank combined with the system. For the
operation and needed settings of domestic hot water in combination
with a domestic hot water tank needed for Switzerland, please refer
to the manual of the heat pump module.
8.4

Operation modes

The following codes on the service display indicate the following
operating modes.
Off
The gas boiler is out of operation but is supplied with electric power.
There will be no response on space heating and/or domestic hot
water demands. Frost protection is active. This means that the
exchanger is heated up if the water temperature in the gas boiler is
too low. If applicable, the keep hot function will also be active.
If frost protection or keep hot function is activated, will be displayed
(heating the exchanger). In this mode, the pressure (bar) in the
space heating installation can be read on the main display.
Waiting mode (blank service display)
The LED at the button is lit and possibly also one of the LEDs for
the domestic hot water comfort function. The gas boiler is waiting for
a space heating and/or domestic hot water demand.
Pump overrun of space heating
After each space heating operation, the pump continues to run. This
function is controlled by the outdoor unit.
Installation and operation manual
30
Boiler shutdown when the required temperature is reached
The boiler controller can temporarily stop the requested space
heating demand. The burner will stop. The shutdown occurs
because the requested temperature is reached. When the
temperature drops too fast and the anti-cycle time has passed, the
shutdown will be cancelled.
Self-test
The sensors check the boiler controller. During the check-up, the
boiler controller does NOT perform any other tasks.
Ventilation
When the appliance is started, the fan goes to starting speed. When
the starting speed is reached, the burner is lit. The code will also be
visible when post-ventilation is taking place after the burner has
stopped.
Ignition
When the fan has reached its starting speed, the burner is ignited by
means of electric sparks. During ignition the code will be visible on
the service display. If the burner does NOT ignite, a new ignition
attempt occurs after 15 seconds. If after 4 ignition attempts the
burner is NOT yet burning, the boiler will go into fault mode.
Domestic hot water operation
Not applicable for Switzerland
The domestic hot water supply has priority over space heating
performed by the gas boiler. If the flow sensor detects a domestic
hot water demand of more than 2 l/min, space heating by the gas
boiler will be interrupted. After the fan has reached speed code and
ignition is done, the boiler controller goes into domestic hot water
mode.
During the domestic hot water operation, the fan speed and hence
the appliance power are controlled by the gas boiler controller so
that the domestic hot water temperature reaches the domestic hot
water temperature setting.
The domestic hot water supply temperature must be set on the user
interface of the hybrid module. See the user reference guide for
more details.
Domestic hot water comfort function/Frost protection/Keep
hot function
Not applicable for Switzerland
appears on the display when either the domestic hot water comfort
function, the frost protection function or the keep hot function is
active.
space heating operation
When a space heating request is received from the outdoor unit, the
fan is started, followed by the ignition, and the space heating
operation mode. During the space heating operation, the fan speed
and hence the appliance power are controlled by the gas boiler
controller so that the space heating water temperature reaches the
desired space heating supply temperature. During the space heating
operation, the requested space heating supply temperature is
indicated on the operating panel.
The space heating supply temperature must be set on the user
interface of the hybrid module. See the user reference guide for
more details.
9

Commissioning

Especially for UK:
At the time of commissioning, complete all relevant sections of the
Benchmark Checklist on the backpages of this document.
Daikin Altherma hybrid monobloc – Gas boiler module
EHY2KOMB28+32AA
4P538953-1 – 2018.06