Defrost without no reason?

Hi Heat geeks

My heatpump seems to want to defrost without no reason. Anyone ells have the same issue?


Welcome Lars!

Where do you see your heat pump defrosting in the graph? Do you mean those intermittent spikes in energy/heat? They don’t look like defrost cycles to me as flow & return temperatures didn’t switch (flow is still > return). What’s the make/model of the pump?

As André says, these spikes aren’t defrosts. There’s a correlating jump in electrical usage at the same time, which suggests either a) the compressor is working harder for a little while, or b) an electrical heater has turned on to boost the heat. Or something else maybe.

Odd that measured heat is lagging behind the rise in flow temperature. How use this system being monitored?

There were some legitimate defrosts this morning (Apr 20) as the temperature dropped near 3°C. This is what a defrost looks like on your system:

Not sure now return temp can be going up; that’s odd.

Hi Andre
Yes i mean the spikes. My guess is that some parametres in the heatpump trigger a defrost cycle but it is not doing a complete defrost because som other factors quickly changes when it tries and the stop doing it. I will try looking in the different menues for parametres to try.
Heatpump is a SPRSUN EVI R32 12KW

Hi Timbones
Yes i allso have normal defrost cycles that looks like the one you posted. No electrical heating element in my setup :blush:

VERY common with heat meters. They have an integration period over which they measure temperature/flow rate and then calculate the delta energy/update the “instantaneous” values sent to the display/made available on the kbus etc. Typically 4, 10, 32, and sometimes even 64 secs; even if the measurements of temperature/flowrate are e.g. every 1 second