Troubleshooting He - Danfoss EvoFlat Four Pipe System Montage- Und Betriebsanleitung

User manual

14. TROUBLESHOOTING HE

Problem
Too little or no heat.
Uneven heat distribution.
HS supply temperature too high.
HS supply temperature too low.
EvoFlat Four-Pipe System
Possible cause
Strainer clogged in HS or HE circuit
(radiator circuit).
The filter in the energy meter on HS
circuit clogged.
Defective differential pressure controller. Replace main controller, TPC.
Sensor defective.
Automatic controls, if any, wrongly set or
defective - possibly power failure.
Pump out of operation.
The pump is set at too low speed of
rotation.
Air pockets in the system.
Limiting of the return temperature
adjusted too low.
Defective radiator valves.
Uneven heat distribution in building
because of incorrectly set balancing
valves, or because there are no balanc-
ing valves.
Diameter of pipe to flat station too small
or branch pipe too long.
Air pockets in the system.
Defective controller. The controller does
not react as it should according to the
instructions.
Defective sensor on self-acting thermostat. Replace thermostat.
Defective controller. The controller does
not react as it should according to the
instructions.
Strainer clogged.
Solution
Clean gate/strainer(s).
Clean the filter (after consulting the HS
plant operator).
Check the operation of the thermostat –
clean the valve seat if required.
Check if the setting of the controller
is correct – see separate instructions.
Check the power supply. Temporary
setting of motor to "manual" control –
see instructions on automatic controls.
Check if the pump is receiving power
and that it turns. Check if there is air
trapped in the pump housing – see
pump manual.
Set the pump at higher speed of rotation.
Vent the installation thoroughly.
Adjust according to instructions.
Check – replace.
Adjust/install balancing valves.
Check pipe dimensions.
Vent the installation thoroughly.
Call automatic controls manufacturer or
replace the regulator.
Call in automatic controls manufacturer
or replace controller.
Clean gate/strainer.
© Danfoss | Produced by Danfoss Redan A/S | 2020.06 | 27