Honeywell EN2H-0221GE51 R0808 ユーザーズマニュアル

SDC / DHC 

Hydraulic Components 

EN2H-0221GE51 R0808 

161 

Indirect return increase is realised by means of the mixed heating 
circuit valves in the heating circuits. It only works for systems 
without a bypass pump and without controlled flow mixing. 

When this function is active, two values are calculated 
independently for regulating each mixed heating circuit. The first 
value is the control variable for the flow setpoint of the heating 
circuit; the second is the control variable for the return setpoint. 

The control variable used for mixed heating circuit control (mixed 
heating circuit control variable) results from the superimposition of 
both values. In this the adjustment of the return temperature is 
treated with priority. 

Indirect return control is only active with mixed heating circuits 
that are in heating operation as well. It does not affect a heating 
circuit in reduced operation. 

To avoid excessive pulsing, we recommend enabling the 
connected consumers (heating and hot-water circuits) with 
staggered switch-on times. 

This function does not affect direct heating circuits. 

 

Indirect return control is only feasible for systems without bypass 
pumps and without controlled flow mixing. 

 

 

The prerequisite for a constant room temperature is the exact 
setting of the heating curve of the relevant heating circuit as well 
as a correct design of the heating system on the part of the 
heating technician according to the heat demand calculation. 

If adjustments are necessary, they should be made in small steps 
at a distance of a few hours to assure that a steady condition is 
obtained.