Home Forums General Discussion Heatpump Hotwater Cylinder Programming Reply To: Heatpump Hotwater Cylinder Programming

Andrew Pollard


Placing the cylinder outside does increase the heat losses from the cylinder and doesn’t allow the losses to offset heating required for the home. Many older indoor cylinders (which had a bit of heat loss) provided some warming making the hot water cupboard the defacto linen cupboard.
I had a look at some of the programming modes of for the unit and it does seem to have a lot of intelligence – automatic legionella control, communication with PV systems, One shot (or automatic) boosting weekday/weekend programs and ‘PLUS’ enhanced comfort functions.
With the Legionella control being automatic (it does a full cycle once a week) you would be able to reduce the setpoint of the cylinder down which would reduce heat loss (but would reduce the heated capacity). Most bathing water is 40-45°C so the 200L bath may only be 120L?? of 55°C?? water mixed down with cold water. Laundry and Kitchen may need the hotter water though (often taken off before the tempering valve).
Some of the program modes get in the way of efficiency. The ‘PLUS’ comfort mode (to ensure there is lots of delivery water) uses the electric resistance boost when the air temp is below 10°C so turning this off when have an efficiency improvement but you have to be careful you are getting the service (amount/timing) of hot water you are expecting.
Its probably a learning experience. I’ve talked to people with basic temperature read outs of the water temperature on their solar water heating systems and they’ve know how much water they can draw for a certain temperature etc – when to engage the boost controls, etc.
I hope this helps