18
VUT 160/250/350 PB EC
www.ventilation-system.com
3. Fan maintenance (once per year).
Even in case of regular maintenance of the filters, some dust may accumulate inside the fans and reduce the fan performance and supply
air flow. Clean the fans with a soft brush or cloth. Do not use water, aggressive solvents, or sharp objects as they may damage the impeller.
4. Technical maintenance of condensate drainage system (once a year).
The condensate drainage (drain line) may get clogged by dirt and dust particles contained in the exhaust air. Pour some water inside the
drain pan to check the pipe for clogging. Clean the U-trap and the drain pipe if required.
5. Ductwork system maintenance (once in 5 years).
Even regular fulfilling of all the maintenance operations prescribed above may not completely prevent dirt accumulation in the air ducts,
which leads to air pollution and reduces the unit capacity. Duct maintenance means regular cleaning or replacement.
6. Control unit maintenance (if necessary).
The control unit is positioned inside the unit casing. For accessing the control unit remove the fixing screws on the service panel and
remove it.
CAUTION! The control unit maintenance must be performed by an expert qualified for unassisted operations with electrical
installations with the voltage up to 1000 V after careful reading of the user’s manual.
TROUBLESHOOTING
Problem
Possible reasons
Troubleshooting
The fan(s) do(es) not get
started.
No power supply.
Make sure the power supply line is connected
correctly, otherwise troubleshoot a connection
error.
Low air flow.
Filters, fans or the heat exchanger are soiled.
Clean or replace the filters, clean the fans, and the
heat exchanger.
The ventilation system is soiled or damaged.
Make sure the air ducts are clean and intact.
Noise, vibration.
The fan impeller is soiled.
Clean the impellers.
Fan screw connection is loose.
Check tightening torques.
Water leakage.
The drainage system is soiled, damaged, or
installed incorrectly.
Clean the drain line if necessary. Check the drain
line slope angle. Make sure that the U-trap is filled
with water and the drain pipes are frost protected.
