I have my Daikin EDLA 8Kw heat pump installed plus the monitor kit which the installer put in. It is just being used for HW at the moment. Two questions on the data:
Initially I got what I regard as sensible readings for the Heat Ouput and Electricity consumption, now there is a gap between the start of the heat output and it finishing, in this gap the flow temp still goes up and electricity is being consumed with apparently no heat output recorded. What could cause the gap in data?
The second question is the return temp seems to drop immediately the heat pump stops producing heat while the flow temperature gradually drops down, I would have expected them to both drop gradually.
Sorry if these are basic questions, any insights appreciated
Hi again, I think I have resolved my first problem with the gap in the heat output graph. As it is a new install I think air has probably been expelled through the automatic air bleed device so the pressure had dropped. I have restored the pressure to 1.5bar so last night the time period of the heat output and electricity consumption was back to as expected.
Still don’t understand why the return temperature drops off so quickly.
Air in the system is a common cause of invalid Heat Meter readings, so that does probably explain the discrepancy you saw previously.
Presumably your installation has a 3-port Diverter Valve, to swap between heating the DHW tank versus heating the Radiators / Underfloor or whatever you have for Central Heating? It’s common for those valves to return to the ‘Central Heating’ position except when the system is actively heating the DHW tank (even when there’s no ‘call for heat’). I suspect this Diverter Valve is switching to its ‘Central Heating’ position at the end of your DHW cycle so the circulation pump pulls in a slug of cool water from the Central Heating pipework, which gets registered on the Return Temperature sensor.
Would that explanation fit with how your system’s pipework is configured?
Hi David, yes that would certainly fit with the pipework as there is a 10 Litre volumiser tank that it would be drawing from if the diverter valve moves back to CH. The return from the HW tank comes in after the volumiser and before the return temperature sensor so you would get a big slug of cool water from the volumiser as the heating is not active.
Thanks for your insight
