I use cheap overnight electricity to heat my DHW. I have a good size hot water tank and a very large buffer (750l or so). Normally this works well, but when it is cool, the defrost cycle switches the divert valve to take from the DHW, reducing the DHW temperature about a degree each time. I rapidly …

Hi @CoP , Your observation is somewhat at odds with the info I obtained from UK Tech Helpline. They told me that the defrost heat source was whichever system was in use at the time of the defrost demand (i.e. DHW tank during a hot water demand, buffer tank otherwise). In other words, a defrost deman…

Thanks @SarahH ! I don’t think the information from the technical helpline can be right. I’m almost certain that the defrost cycle always switches the DHW valve and takes from the DHW, but I will certainly double check if there is a way around this.

I guess one easy way to check would be to completely disable DHW using the Schedule option on the remote controller one really cold night (when a defrost is likely), and see whether the DHW tank temperature has fallen noticeably afterwards. (It could be - if you have DHW heating permanently enabled …

Related topics about this same issue: [image] Samsung R32 ASHPs - when is a defrost not a defrost? Heatpump I wonder whether we Samsung users have been conflating two controller algorithms… Samsung tell us that real defrosts are subject to the following defrost strategy:…

I’ve had a careful look at this again, and you’re absolutely right. The defrost takes from whatever source the ASHP has most recently been heating. See attached. [Screenshot 2025-07-12 at 23.23.00] What seems to be happening is when the outside temperature is around zero and then the defrost cycl…

I’ve decided on a better solution to address this than the one suggested by Samsung. The problem is when the system runs to prevent freezing. This normally happens during the period during higher rate electricity when the ASHP is set to remain off. If I add a timer to cut the signal to the actuators…

Problematic Samsung Gen6 Defrost Cycle

Hardware Heatpump

Timbones (Tim) 22 December 2024 15:55 5