The boiler maximum return temperature control is switched off by default due the value “999” at the input “RetTempSp”.
You can enter another fixed value as a default at the input “RetTempSp” or you can connect a time schedule or any other program code to override this input.
When the boiler return temperature exceeds the value of the input “RetTempSp”, the burner stages “ModStage” and “Stage1Cmd” will be stopped, while the boiler valve will stay open and the boiler pump on, in order to maintain the total system circulation.
This specific function is needed when a boiler is used in combination with a heat cogeneration system: if the last mentioned system produces that much heating energy, it is no longer necessary to run the boiler.
Table 16. Parameter List
Description |
Value Range |
Default Value |
Unit |
SYS-02: configuration boiler type 1 = minimum return temperature control 2 = maximum return temperature control 3 = no return temperature control |
1...3 |
3 |
- |