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Samsung ASHP starts and runs for 5 minutes before turning off
I am new to the forum. I have a Samsung ASHP installed with a Kodiak cylinder.
The system heats hot water and the under floor heating. The installation was completed 12 months ago. I have noticed that when there is no demand for hot water or heating, when the outside temperature is low, the ASHP starts and seems to circulate water for approx 5mins. Is this correct or can be stopped or minimised?
Hi. This is correct operation. Mine does the same.
House-3 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
10kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
@crawfora I think it might be to do with preventing freezing. The water is warmer in the house so turning the pump on would mix it with the cooler water outside.
House-3 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
10kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
I think that is indeed to do with defrosting. When it does it, can you go outside and see if there is a lot of water falling off the bottom of the heat pump? It is strange to see the first time it happens but when you see theneed to keep frost of it, understandable.
I have the same basic system, if you are in west central Scotland it might have been installed by the same company.
I have noted since installation that the Kodiak cylinders have been known to fail and the manufacturer to be very hard to get to fix them, so I am keeping an eye out for that.
Posted by: @crawforaThanks for the reply, do you know why the ASHP does this?
Hi, it isn't the same as defrosting, which occurs at low outside temperatures when the ASHP is running. What you are noticing is the pump circulating water through the DHW tank and using the heat in your tank to keep the water in the ASHP from freezing. It only does this when the ASHP is NOT running. There is no risk of the water in the ASHP freezing when the compressor is running, but there is when it is cold and the compressor is not running. This behaviour is standard, although it may not be necessary if you have sufficient glycol in your system. I don't have any glycol, so I depend on this behaviour to keep my ASHP from freezing when it is not providing space heating or DHW heating.
Apart from what’s already been said, in some ASHP models, there's a preheating function that can activate in anticipation of potential heating demand. This might involve circulating warm water through the system ensuring faster heat delivery when activated.
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as per mike-h, this happens by default and there is no setting to stop it. the only way to make it not happen by ensuring the HP is running almost all of the time during cold spells. meaning don't set your temps back by much.
worth adding, the HP will open the valve to the HW cylinder when this function activates. It'll take heat out of the HW and use it to warm up the CH pipes all the way round the loop to the outdoor unit, until the outdoor unit is warm enough, then stop and close the valve. This is a poor design decision by samsung in my opinion, there should be enough residual heat in the CH circuit to satisfy this re-warming need. It can be worked around if you're capable with diy electronics .
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