Troubleshooting guide

6
VMIFB202
Tip!
Be careful not to spill water because there are electronics under the radiator pump; use something to protect the electronics.
NOTE! This does not apply to the Optimum series of circulation pumps
On Optimum one measures 0-10V (DC) at the molex switch (marked 0-10V) at the circulation pump while one runs it in a manual test. If
there is no signal measure directly on the relay card terminals (See wiring diagram).
Exchange valve jamming
Action:
Check that the exchange valve moves to its limit positions by running it manually in the service menu.
If yes, disconnect the motor and check that the cone moves easily without jamming.
If it jams, clean/ replace the insert or replace with a newer LK exchange valve (Note! When changing to LK one must replace both motor
and valve because this is the twisting type)
Cable break or loose cable to high pressure switch
Action:
Check that both cables are connected to the high pressure switch. If yes, use a buzzer to check for cable breaks. (disconnect the cables
from the high pressure switch and relay card to do this).
The operating pressure switch does not open but the heat pump opens at high pressure
Action:
Check that the operating pressure switch opens at the correct pressure, check using manometer apparatus.
If the break pressure is higher than the correct pressure there is a fault in the pressure switch.
Troubleshooting Guide Alarm high pressure
Nut for bleeding
the circulation pump
The image shows
pressure switches