Does anyone know whether there is any manual control on the OEM version of the Alpha pump fitted to my 30CDi system boiler? It is supposed to be a modulating pump but it does not appear to change speed at all as the TRVs close and I can't decide whether it is just faulty or whether it is not set up right or matched to my system.
I had a WB engineer look at it and he changed the pump head and system board - no improvement. Is it possible that the sensor/control gear was not changed by this and a fault still exists? In defence of the engineer he had been given no information about this pump.
When most of the TRVs are closed the high flow speed causes a lot of noise in the lounge rads. I know there is a lot of 25mm copper in the circuit and also wondered whether this gave low resistance and, even with a lot of closed TRVs, meant that the pump was not reducing speed.
I have another WB engineer calling tomorrow but would like to know if there is any experience out there that might help diagnose the problem.
By the way, the pump is marked Grundfos Alpha, DDWPM 15-60 and UPER XX-60 J2 and does not appear to have the setting control that is on the standard Alpha pumps.