I’ve asked what the operating window is on the compressor and wonder if insulation is the best route
But as you say only 1kwh a day during the none heating season. Just ruining my overall cop numbers 
I feel your pain Simon, same here but somehow I’ve learned to live with it. What can we do ? This is 1kW in non-heating season without DHW cycle wasted. Yes, COP is ruined 
BTW, what makes me more crazy and wonder how about you is the fact that the pump is stealing heat from DHW tank.
Imagine there is no DHW heating cycle in given day but this STUPID Samsung is doing a 6 minutes pump cycle once per day. FOR WHAT ? And of course it will open DHW circuit for that! This will steal few degrees from my preciously heated water and eventually trigger DHW re-heat. I really wonder what idiot programmed this. Sorry for an expression.
Why it simply does not keep UHF circuit open for this ? Even in winter. I don’t want to open DHW circuit for these anti freezing cycles bullshit. When I did not have DHW there was no problem with that but now with DHW no way, we will steal heat from it. Give me the setting where I can decide!
And why it is doing this once per day in Summer season ? Just for a fan ? When I turn off the pump it is not doing this of course but why it thinks it is a good idea to do this when pump is on and idle ? I don’t need it at all! Wish I can turn off this shit, really. SaraH will say I rant again but is this a rant ? No, it’s desperation
@SarahH outside temp has really nothing to do with compressor heater trigger. There was over 30C here outside and still this heating was triggered.
What is this
H. not inverter check mode.
Can i trigger this somehow ?
No idea, and this is probably no use to you, but I see that something called “Inverter compressor 1 check” can be initiated by pressing the K2 button on the Outdoor Unit 4 times (p165 of the Installers Guide).
I infer from @mrsimonbennett’s list of activation criteria that during an inverter test - possibly an event triggered regularly by a controller timer - the CCH is inhibited.
What have you noticed ??
That the heat pump will randomly turn the pump on and open the dhw valve. I am looking at a way to ignore the call unless the ashp is producing heat
Maybe looking at the power consumption
@Michal_S
I just got this back
Hi Simon,
Thanks for your email.
This looks to be the pump anti-lock function, this will run and take the heat from the mode it is in at the time.
You could try FSV 5022 and change to a 1 this will increase the time in-between runs to a max of 96hrs. with the anti-lock being in the logic you are unable to disable the function as it is a safety feature of the system.
Best regards
David Price
Technical Support Engineer
Ah, this one you mean. Yes. It’s pretty pathetic tbh.
I don’t understand this:
“This looks to be the pump anti-lock function, this will run and take the heat from the mode it is in at the time.”
If pump is running it of course not do anti lock/freeze cycles. This is doing only if pump is idle for some time and some conditions are met. At least once per 24 hours though. But if the both space heating and DHW are idle it will always open DHW circuit for this no matter what and this is what is bugging me.
Imagine in winter you turn off heating at night from 00:00 to 6:00. Because it’s below 5C outside the pump will do anti freeze cycles every few hours maybe 4 time per night and it will ALWAYS open DHW and steal heat from DHW tank (2c per run roughly). So you wake up and your tank is 10C less as it was at the midnight for nothing.
This is just horrible design. When I did not have DHW tank pump was also doing these cycles but of course it circulated water over space heating circuit and there was absolutely no problem. With DHW connected it behaves like a thief. So now if my heating is turned off during night the first thing in the morning is that HP needs to reheat the DHW tank!
I’ve cheated it with connecting 2 relays and with a help of home assistant I’m switching the relays as needed to control 3-way valve position. In case I detect the pump is doing anti locking or anti freeze cycle I will switch relay so it will not open valve to DHW circuit. Only if I detect there is really a call for DHW heating I will allow 3-way valve to open to DHW circuit. Yeah it’s not ideal solution but haven’t found anything better. It depends on HA so if it fouls up then I could have 55C in radiators
And all this just because of stupid engineering. This could be solved by a simple field setting “Circuit for ant-locking/antifreeze: DHW/Space”. Easy like that. No, they decided to steal heat from your preciously heated cylinder
Ah.
What exactly is this DHW saving #5022 ?? I’ve set it to 1 now so I’m curious what it will do…
@Michal_S any improvements?
Is your system public on heat pump monitor?
The manual says that if #5022 is enabled the controller will reduce the target DHW temperature by an amount below your remote controller target setting, as defined in #5021.
The default #5021 is 5degC (you can vary this between 0degC and 40degC), so if your DHW target is 50degC and you enable Saving Mode by setting #5022 to 1, then your DHW will only be heated to (50 - 5) = 45degC.
Well, improvement is that with these relays solution the pump does not steal heat from DHW tank. It’s a bit awkward but seems it works pretty reliable.
#FSV 5022 seems does nothing in this regard. I think they didn’t understand what you are asking. How this 96h delay can postpone anti-seize or anti-freeze runs ? It’s bullshit. It still takes heat from DHW no matter you set the parameter to.
Modulation still sucks with higher outdoor temperatures. It works pretty OK with freezing temps but above +5C it’s a pain. Never seen a pump with such bad modulation. I don’t know why it needs to jump from 600W to 1000W every couple of minutes and all over again instead some linear increase/decrease. That controller in my pump must suck or the firmware is wrong there.
@SarahH yeah, so how does this help with stealing heat?
Defo seems strange ive not had any random pump runs since the system has been on more often.
Can you remind me what size pump you have and your heating output.
My heat pump does something like this when modulating which is a bit annoying
Once I get to DT ~13 I stop modulating (this should decrease as adding another 3 rads to the system this week, kitchen is unheated at moment)
But mine also does a bit of what I can only describe base on look saw toothing.
Which is annoying when the pump then cuts out due to LWT been two high, I feel maybe if you ran the compressor at the lowest power all the time you would cycle less! But there might be some more phyicas with gas and oil going on that I don’t understand.
Its is annoying that COP is actually increased when its working a bit harder instead of cylcing. I was going to explore something that keeps bumping the set temp up.
Currently I am controlling the flow temp using home assistant and some WC calculations and settings the LWT target. I tried weather law and the effect is still the same
Mine does the same. The modulation is not smooth with low power input. Granted it could be because of low water volume in the system so inlet/outlet water temps reacts fast so does the pump. Also I have radiators so the heat exchange at lower water temperatures is not that great. I guess if I would add another 200l tank would help but it’s a meh.
Yes, the pump needs to work in optimal condition ho achieve high COP. That means high water volume and big heat exchange surface. Then your fan will work fast so the heat transfer from outside into the water is great. When there is above 5C because of my system the FAN is barely moving and that means heat exchange is slow so the COP is going down.
You simply can’t make it much better without increasing your heat exchange surface area or adding a big buffer tank into your system or buying a pump with better modulation. My unit is 8KW and the lowest power input is 600W and it’s very inefficient with my system. I would need something which can go to 250W maybe… Then the FAN could spin much faster to get more heat from outside. Yeah, it’s complicated but I’ve come to terms with it.
That’s why I’ve set min. 40C above 0C because with WL curve I need Samsung would give 30C at 10C or so which first is simply not possible and 2nd very inefficient causing overheating a very low efficiency. I would need maybe 45C from 5C+ and above.
For me pure WL is not usable, it cycles very often and I have to use roomstat instead.
Sorry Michal, I was only explaining my understanding of how #5022 was applied, and not suggesting that it could affect DHW tank heat removal.
[My own solution to the latter will not appeal to you. I organise my lifestyle around DHW heating - I only heat the tank 2-3 times per week, immediately prior to pre-planned demands (e.g. family showering, washing machine use). After these demands, the tank is no warmer than the CH circuit, so I don’t really care what the controller does to the 3-way valve during any frost prevention run. (Before you ask, we use a dishwasher, so can manage without any hot water on the other days.)]
Hi Alun,
I have a gen 7 16kw Integrated unit. I cannot get the water pump PWM from the register you listed. I also get Flow Rate from 0x4012 maybe my unit uses different registers. Is your unit a gen 7 unit?
Cheers
@SarahH Do you have any idea how I can get the water pump PWM % or the Indoor temperature? Also is it possible to have both teh modbus and NASA connections simultaneously connected. I can easily add another Waveshare to the network and connect it to the other terminals. I can spin up a windows VM on teh ESXI server to run the windows only Samsung software. Does that have any kind of API you can automate setting FSV’s etc.
Cheers
Yes, that is the way my Gen6 is connected up at the moment. I started off using Modbus and then moved over to NASA. All control is now via NASA, but the Modbus interface is still ticking away in the background.
Ah ok, Many thanks for this. I need to figure out the routing of another cable out to the unit then it seems.
Definately can’t find the Pump PWM% and Indoor temp data.
Cheers
Does anyone know if there is a modbus register for FSV #2054 Inverter pump minimum PWM output?
Cheers
IS ti possible to leave the wired remote control (wifi unit) and also connect a RS485 device to the NASA outputs?
Cheers