Danfoss VVX-I Operating Manual page 25

Operating Guide Termix VVX-I with complete insulation
Too high DH return temperature.
Noise in system.
Heat load too high.
AQ082486478026en-010501/ LUK4044301
Too small heating surface/too small
radiators compared to the total heating
requirement of the building.
Poor utilization of existing heating surface.
Defective sensor on self-acting thermostat.
The system is single pipe loop.
Pump pressure too high.
Air in system.
Defective or incorrectly set radiator valve(s).
Single pipe loop systems require special
one-pipe radiator valves.
Dirt in the motorized valve or in the
differential pressure controller.
Defective motorized valve, sensor or
automatic controller.
Electronic controller not adjusted correctly.
Pump pressure too high.
Defective motorized valve, sensor or
electronic controller.
Increase total heating surface.
Make sure the heat is distributed evenly
across the full heating surface – open all
radiators and keep the radiators in the
system from heating up at the bottom. It
is extremely important to keep the supply
temperature to the radiators as low as
possible, while maintaining a reasonable
level of comfort.
The system should feature electronic
controls as well as return sensors.
Adjust pump to a lower level.
Vent the system.
Check – set/replace.
Check – clean out.
Check – replace.
Adjust according to instructions.
Adjust pump to a lower level.
Check – replace.
© Danfoss | 2023.10 | 25