High operating temperatures and poorly performing HIUs meant heat loss levels were high, resulting in overheating. This also impacted cold water temperature in the dwellings, with water being heated to temperatures that residents complained were uncomfortable.
The poor valve control in the HIU also meant that residents had to wait an unsatisfactorily long time to get hot water at their taps.
Residents were also dissatisfied with the frequent HIU breakdowns and the subsequent maintenance costs to fix them. They had also complained about their billing system which didn’t provide sufficient information about their balance or how much energy they were using.