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Heating  Heating

Brand

Wiliamson Wiliamson List all brands

Type:

FS-120NGFS-120NG
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Error code:

FAULT 21 =
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Error code: FAULT 21 =

Cause of error code FAULT 21 =

The water pressure in the CH installation is near the high level

Solution for error code FAULT 21 =

Warning – The water pressure, measured by the water pressure sensor, is higher than the high level –4.3 psi and lower than the high level. This is only an indication, the heat request is not switched off but there is a linear output reduction in this way: if water pressure >= water pressure high limit -43.psi there is no limitation, if water pressure >= water pressure high limit -2.9psi then the maximum output is equal to ( fan absolute DHW maximum speed- Fan absolute minimum speed), if water pressure>= water pressure high limit -1.5psi then the maximum output is equal to Fan absolute minimum speed + 20Hz.


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