Manual Test Run Of The Heat Pump; Start The Heat Pump With Only Additional Heat; Important Points To Check After Start Up - Bosch EHP 6-11 LW User And Installation Manual

Manual test run of the heat pump

Instead of starting the heat pump directly in normal mode, you can manually test run
the pumps and valves. This is recommended as in this mode you can easily fi nd any
possible faults. In the menu display Manual operation of all functions (menu 5.3) you
can run all functions manually. Press the Select button to start test operations. When
you exit from the menu display the heat pump returns to normal mode.

Start the heat pump with only additional heat

It might be necessary to run the heat pump before work on the heat transfer fl uid
circuit is complete. You can then start the heat pump with only additional heat. You
must have fi lled and vented the heating system to run the heat pump with only ad-
ditional heat. Go to the menu display Select the function only add. heat (menu 5.4) and
press the Select button. If the arrow points towards Normal operation press the Adjust
button. Turn the menu dial until the arrow points towards Only add. heat. Now press
the Save button. This function ensures that additional heat heats both the hot water
and the heating water.

Important points to check after start up

In the fi rst period after commissioning particular attention should be paid to the
pressure and levels in the heat distribution and heat transfer fl uid circuits. After a
short period of operation it may be necessary to top up the heat transfer fl uid.
On delivery the motor cut-out setting is determined by a value produced during hot
water charging and a stable voltage. The recommended motor cut-out setting may not
always be suitable as the voltage in the mains can fl uctuate. The setting may therefore,
from case to case, need to be adjusted. Adjust the setting using a clip-on ammeter
when the heat pump is producing hot water.
For the heat pump to perform at its best, it is important to check the fl ow on the hot
side of the heat pump. Usually, the heat carrier pump has a speed selector switch.
This must be set correctly for the pressure drop in the systems. A recommended
temperature difference over the heat pump on the hot side is between 7-10 °C and on
the cold side between 2-4 °C. You check this by going to menu display 3 and reading
the sensors T8 (GT8) and T9 (GT9) as well as T10 (GT10) and T11 (GT11).
It is important in systems with a bypass that the fl ow in the heating system exceeds
the fl ow over the heat pump. If this is not the case, the heat pump fl ow goes back via
the bypass to the heat pump return, which may cause the heat pump to give an alarm
for a high return temperature. The fl ow over the heating system should be so great
that the entire radiator surface is kept warm. In this way the heat emitting surface
increases and in doing so the fl ow temperature from the heat pump is kept down.
The heating system should be vented once again after test operations and then fi lled
with cold water if necessary.
Do not forget to return this function to
normal mode.
71
Commissioning the heat pump
Commiss./Service
Manual operation of
all functions 5.3
Return Select
Commiss./Service
Select function
only add. heat 5.4
Return Select
Note