Residual Pump Head

[John Carroll]

I’ve been asked numerous times to explain the residual pump curves published in some Vaillant Ecotec Boilers MIs, I’ve looked at them several times but afraid I can’t make any sense of them. Someone on here might explain them or/and post similar curves from their (Vaillant) HP circ pump curves, if available.

The first screenshot shows my calcs based on a typical 7M circ pump, second screenshot is the Vaillants and the third is unknown but does make sense.

The Vaillant’s constant pressure residual default setting is 250mB, 2.5M. At this setting, mine shows a flowrate of 1200LPH (20.0LPM), unknown’s 1300LPH & vaillant’s 1230LPH, much of a much. At 70% pump speed (72% for unknown’s but won’t have any big effect vs 70%) mine = 540LPH (9.0LPM), unknown = 620LPH (10.3LPM), again not hughely different and probably explained by pump differences but Vaillant = 1150LPH (19.2LPM), can’t figure this out but one would think Vaillant have some basis for publishing these figures??.

Residual Head.docx

Edited 18 hours ago by John Carroll

[John Carroll]

Here's a dynamic version to check your own systems.

Residual Pump Heads Rev1.xlsx