I have a WBosch CD53i (Mark 1) which has recently started to Lock Out after running Hot water demand for a long time (e.g. Filling the bath). Short bursts of demand are ok. According to the installation / servicing manual, the fail point (G) indicates to check the CH pump is working, then the DHW pump, and then a few voltage checks on the control board.
The DHW pumps would appear to be working (it makes some noise when demand is on), and the after only 10seconds or so after the demand ceases, the pump stops.
My questions are:
1) How to be sure the pump is rotating?
2) How long after demans should the pump run?
3) Surely the DHW pipe work is not a loop like the CH pipework, so what good does it do to run the Pump after the demand has finished - surely there is no where for the water to disperse?
The DHW pumps would appear to be working (it makes some noise when demand is on), and the after only 10seconds or so after the demand ceases, the pump stops.
My questions are:
1) How to be sure the pump is rotating?
2) How long after demans should the pump run?
3) Surely the DHW pipe work is not a loop like the CH pipework, so what good does it do to run the Pump after the demand has finished - surely there is no where for the water to disperse?