Hi Sarah,
Thank you so much for raising this - I really appreciate it.
Good news. K-button would really be a option (and some modbus address as well:)). Why not implement it. It costs nothing and users will be more satisfied. Buy I would give it 10% chance of success because from my own experiences these companies does not listen to customers at all.
BTW, do you know if there is a way to upgrade software on the pump on my own? Or at least check latest versions for my pump because I have no idea what firmware I have and whatās available.
Until then I guess my solution with relay an HA is best one available 
I can give a little information, including a DONāT DO THIS warning, based on very recent harrowing experience.
As you know, I use SNET-Pro2 to monitor my AE080BXYDEG/EU (the EHS Mono Low Temp aka HTQ). The downloadable version of SNET is 1.13.9, but UK Helpdesk recently sent me an updated version 1.14.3. SNET displays all the available FSVs which you can modify from your laptop, and I noticed that the new version now included (for example) #1061/2/3/4 (hysteresis settings for LWT and roomstat), but SNET wouldnāt let me change them as my firmware did not support them.
The Helpdesk advised that my firmware could be updated to suit the new SNET, either using a MIM-C02N (which costs about Ā£200) or by direct file upload of a hex file they sent me, using an SNET option (though the latter would be at my own risk). As I didnāt own a MIM-C02N I decided to risk the file upload. MISTAKE! It irretrievably jammed my controller and (maybe a coincidence) clobbered the controller in my water circulation pump.
Helpdesk then told me that I would need to replace the whole MIM-E03EN circuit board and gave me the required Part No. (DB92-05469A, MIM version 01 ā my old MIM was apparently version 00 ā obtainable from Heron Hill for about Ā£135 + Ā£15 shipping + VAT, around Ā£180 total). They also advised that I would need to transfer the EEPROM from my old PCB to the new one in order to retain my system settings. (Apparently the FSV setup resides in the Micom, which is also on the PCB.)
Luckily my original installer was able to fit the new PCB just hours after it arrived from Heron Hill, including the EEPROM transfer, though he also had to replace the circulating pump which had gone short circuit, and he mis-wired the comms connection between the Outdoor Unit and the controller, which resulted in an E202 error moments after he left (this is 5PM on a Friday so no CH or DHW for the weekend).
Fortunately (for my familyās sake) I was able to diagnose the wiring problem and fix it, so as of a couple of hours ago I once again have a fully working heat pump, AND I have all the new FSVs to play with 
. Unfortunately, the User Manual for version 01 is not readily available, though some kind soul on this forum found it somewhere, so if you go down this route I can get a copy to you.
Lessons (re)learned: 1. If it aināt broke donāt fix it, 2. Donāt dabble if you value your warranty, 3. If youāre not sure how to do it, pay an expert.
What a terrible experience. But itās not really surprising, given how the firmware is unprotected and other, you could even flash something totally out of scope of your device 
Lesson learnt I guess, but on my side, I really want to play with the JTAG Download link to mess around the firmwareā¦
Cheers
Interestingly, when I replaced my PCB under warranty just 1 month after install, it also gave me the new FSVs to play with (which have definitely helped reduce cycling). Makes me think that my controller must have been sat in stock longer than the PCBs had been. But unsure why updating them to the latest software isnāt a key priority when installing them. That might have just been my installer though.
I might have been the kind soul, but Iām not sure what I sent now. If I need information on the new FSVs, I look at the manual for the MIM-C03FN from the midsummer websitehttps://midsummerwholesale.co.uk/buy/samsung-heat-pumps/samsung-mono-control-kit-mime03fn.
It is their new āAIā 
controller. Thereās nothing AI about it. It just seems like something Samsung are slapping on everything from washing machines to fridges (see image below). It does have a new colour display. But thatās about all thatās changed as far as I can tell. I did mean to ask Nick K if there were any new features or settings that we could get with this, but never did.
Indeed you were the kind soul, @jakeymd1. I found the link you previously provided in Samsung wired remote controller as thermostat, Gen 7 Samsung? , post #18 or thereabouts. As you say, there doesnāt seem to be much difference to the document you link to aboveā¦
Ouch, Iām sorry you had to go through that. Really painful. I will better stay away from this. I doubt it would help anything anyway.
Do you know if Samsung has some setting for LWT overshoot ? E.g. if the pump canāt keep with target water temperature it could continue to heat a little bit more at actual power input like few degrees to help stabilize the pump in case thermostat is in use. Could somehow prevent that zigzag pattern which is shown when there is so much het and pump canāt run stable at given flow temp. It would be pretty handy in my opinion but I donāt think there is something like that.
Also what is your opinion on stratification pump for DHW ? I was thinking to add a small pump which would mix the water when DHW heating is active taking hot water from outlet and pump it at bottom of the tank. This way it could heat whole tank to target 50C temperature. I have a tank where the coil is running from the very top to very bottom of the tank. The surface area is 3m2 (itās 300L tank) but because of heat goes up the coil in 1/3 is inefficient.
Speaking of dangerous operations, Iāve had time to discover that there is a way to force valve direction through NASA packet. However, it requires to switch the unit into manual mode (through NASA too), however, I cannot seem to find a way to reset that manual mode but resetting the indoor unit.
However that manual mode allows to drive pretty much every valve/heater of the indoor unit (E03xN controller). I have only mapped zonesā and dhwās valve, I miss the 3 way mixing valve, and all heaters.
This is definitely not an alternative to driven relay. The relay way sounds way less dangerous and random. However, maybe one day Iāll have something doable.
Also, during that process of understanding that manual mode (or maybe maintenance mode?, but definitely not the test mode from the wired controller, itās something different), I came to a rather weird conclusion, why not resetting the indoor unit when the anti freeze behavior is detected. Yes that would prevent anti freeze at all, but I wonder if thatās efficient against the case weāre trying to investigateā¦
Cheers
Other than setting #2093 to 1 (which can result in LWT exceeding its WL target if the roomstat isnāt satisfied), I donāt think so. But Iām wondering whether resetting the hysteresis (per the above discussion on FSV#1061ff) might achieve this? Your lowish emitter thermal inertia (you have no volumiser, I think), coupled with your low WL setting, may be causing your controller to āhuntā. #1061 - if you had it - would allow you to set up to 7degC hysteresis (rather than the fixed ~2degC default). But this might mean buying a new PCB 
.
On DHW stratification, I personally think that it is a good thing, at least for my requirements. It keeps the top bit of the tank warm for a day or two after a DHW heating run. If I did want some really hot water, I think it would be cheaper to boil the kettle occasionally than to install a circulation pump on my DHW tank. But if your tank coil is too far up, and you really need the full 300l of hot water every day, then a new pump may be cheaper than a new tank 
.
I do have an idea to cope up with the DHW heat cycling. If you can detect the moment itās undergoing and want to cope with it, then switching on TEST MODE and changing manually the DHW valve direction is definitely an option. Then you disable test mode after few minutes, and everything should be ok.
Has anyone tried that so far?
Thanks, well I have set this to 1 but LWT wonāt exceed WL tarted. Thatās the problem and thatās why the pump goes into oscillation between 22Hz and 14Hz when LWT is approaching target WL temperature
I think when I would use 2, 3 or 4 it would switch the compressor off also without thermostat satisfaction so quiet donāt understand why this mode is good for ? Could you maybe explain what each mode mean? WL Thermo off ā> water pump off is mode 2. WL Thermo off ā> water pump on is mode 3 and mode 4 is WL Thermo off ā> water pump 7 min off ā> 3 min in ā> ā¦ what does this mean exactly ? And when in WL mode the pump decide when it should switch off? if it when LWT reach target WL temperature ? Itās immediately or after some time ? This is really not clear no me and if the pump switch off when it will starts again ? I mean it stops the pump because LWT reached target temp but then the water pump stops and when heat pump decides to heat again ?
#1061 I donāt have unfortunately. So now itās 2C by default but what exactly this means ? it is target temp +2C or target temp -2C ? Now I can see the pump starts to modulate compressor frequency a bit around 1.5C below target and 0.5C below target it start to oscillates heavily
Regarding stratification - of course itās a good think but I mean mixing only when pump is heating the water. Not when DHW heating is off. I have this kind of tank. You see coil at the top is pretty inefficient with HP.
What exactly do you mean ? When I detect AF/AS run then I should switch the pump to test mode ? What you mean by manually switching DHW valve ? Can you elaborate your idea ?
I meant that when you detect heat being drained for the anti freeze condition, you could indeed send the TEST MODE request to the heatpump to only switch the DHW V3V valve into Heating position instead of Tank, to make sure the heat is not stolen from the precious source.
By āmanuallyā I imply requesting the indoor controller board to flip the valve direction, and not let the indoor controller doing it by itself (and hence avoiding AF/AS to drain heat from the tank).
// Enter test mode
write 0x4086 = 0x01
// request heating direction for DHW V3V
write 0x4246 = 0x0000
(requesting the other direction depending on how itās installed would be 0x4246 = 0x0020)
// wait a bit
// reset test mode
write 0x4246 = 0x0000
write 0x4086 = 0x00
I hope that could be useful (and that it actually works)
Cheers
Interesting but Iām afraid it will not work. The pump might have to continue AF/AS cycle at valve position you have currently open and do not allow switch the valve. I saw this when Iāve detected AF cycle and then disabled DHW completely. The pump finished AF cycle and only then switched valve back to space heating.
But Iām going to test it once it gets cooler here. It is possible to set it via modbus ? In NASA protocol Iāve found only 0x4086 but without description. 0x4246 is missing completely in NASA. Where are these addresses from ?
Also you said write 0x4246 = 0x0000 then wait and then again do i need to write 0x4246 = 0x0000 ? Or is enough to enable test mode, wait and then disable test mode ? I have valve in default position for heating.
Dear @Michal_S
Iāve written an emulator to connect the wired controller and reversed many of its behacior that were not described in everywhere I looked previously.
The first 0x4246 =0 is optional but wipes the previous state if any.
Iāve also reversed other things, amongst it I can assure you the test mode prevails on the valve operation whatever the af/as/heating mode being currently executed.
Yes you can send those values through modbus, Iām doing through f3/f4 but it also works on f1/f2.
Cheers
@Michal_S I would refer you to the first few posts on Struggling to get to grips with my Samsung controller . These hopefully clarify just what each option in #2093 does, both to the circulating pump and to the heat pump compressor (the manual terminology can be a bit ambiguous). Additional information appears in the Installers Guide https://midsummerwholesale.co.uk/pdfs/ehs-install-guide-samsung.pdf - see p135 in particular, which notes a 1-minute delay to pump stopping with some settings.
Pay particular attention to Helpdeskās reply reported in post #2 in the above thread, about the compressor behaviour when #2093 is set to 1 - if the roomstat isnāt satisfied even with the compressor at minimum speed, it stays at that speed and the LWT rises above target until the roomstat is satisfied (though thatās my interpretation of their words).
Funnily enough, Iāve never seen my compressor go below 20Hz (though I confess I donāt watch it 24/7 like some people doā¦ ). I canāt explain whatās different - we have the same series HP and controller 
. Maybe we should compare our FSVs side-by-side? (BTW I use a 3rd party wireless roomstat so use #2092 rather than #2093, but the rules are the same for each AFAIK.)
Regarding hysteresis, the Remote Controller thermo switches off at setpoint, and back on when the LWT has dropped ~2deg below this (unless you have #1061 available). I donāt know whether the Samsung Remote Controller applies a bit of 2- or 3-term control as LWT approaches setpoint. Maybe they do and thatās whatās causing the problem - the controller anticipates arrival at setpoint (in order to avoid overshoot) and backs off a bit too quickly so the compressor speed drops too much. I had to ādetuneā my 3rd party roomstat to avoid exactly the same problem (the TPI cycle rate was too fast for the Samsung controller, but slowing it to 3-4 cycles per hour did the trick).
Thanks @SarahH. Yes, this is really strange. How does your pump works when there is warmer weather outside ? You really donāt have any zig-zag pattern even if there is +10C outside ? Could you maybe share chart of power consumption, compressor frequency for two subsequent days ? I would like to see how your pump is operating excatly.
I was using also external thermostat but the behavior was the same. The only (but big) benefit was that you could adjust WLT temperature by +5/-5C on wired controller. For some reason I donāt understand this is not possible if you are using wired controller roomstat. In that case it only allows you to set room target temperature but not WLT offset. One way or another, the behavior of the pump and zig-zag pattern were the same.
You also have 3āphase HP right ? FSVs we can compare, I can make photos of mine, which FSVs are you particularly interested in ?
BTW, what #2093 settings do you use ?
This is right but problem is that it is doing it in a nasty way Itās not like it slowly continues on 22Hz but it starts to shifts compressor frequency every minute from 22Hz to 14Hz causing this zig-zag pattern. Yes, it holds target temp more or less but usually the LWT is lower than target by one or two degrees and of course efficiency is not the best. And ofc is pain to watch. If you are near the pump you can hear how compressor changing speed every minuteā¦ I donāt know if this is healthy for the compressor in a long run. Out of curiosity maybe you could ask Nick what he thinks about it next time you will be in contact with him.
Now I know maybe more what 2093 is doing but not sure 100% what 2 - 4 are doing exactlyā¦.
-
Question - when exactly the pump send the command thermo off ? I know itās either because thermostat is satisfied or WLT reached target temperature ? Itās immediately or when pump exactly stops the compressor in case of water law ? I donāt believe itās immediate because outside temperature can change every few minutes right ? It is like it has to be running at target flow temperature for some time ? Or what triggers the stop exactly in weather compensation mode ? This is not clear to me
-
When the pump decides to stop because of WL then when the compressor starts again ? What triggers it ? I mean if you have 2093-2 - pump status Off (1min delay) - what does it mean ? Does it mean that after the compressor shut down the water pump is running for a minute and then it stops ? And how the pump knows it should start compressor again ? if the pump stops how does it know itās time to start heating again ? I simply canāt get it. In case of 2093-3 - does it mean after compressor shut off then the pump is running constantly ? Here the system has overview of LWT and RWT but when does it know it should start the pump ? When LWT drops by 2C or how does it work ? Or RWT drops by 2C ? Problem with radiators is when you switch off the pump these temperatures decreases fast right ? At least in my system
And then we have 2093-4 - 3 minutes on / 7 minutes off / 3 minutes on etcā¦ But again what is the trigger the heatpump starts heat again ?Iām trying to understand this so I can move on
I had bad experiences with it especially when I didnāt have frequency ratio control enabled and had low flow temp set in warmer weather. It heated up very quickly and the pump were cycling like crazy. Is there some minimum time for what compressor needs to be off after previous run ? I remember I had 7 starts in an hour or so, it was crazy.Here you are talking about hysteresis when remote controller thermostat shut off the pump or about WL ? So e.g when target is 40C and I have 2093-4 for example and if I have hysteresis set to 2 then pump starts again when WLT drops from 40C to 38C ? And if I have hysteresis 7C then from 40C to 33C ?
From this chart you can see that when the pump stopped I had 38C flow temp and return 34C. But at the time the pump stopped temperatures were equal 34C and when the water pump stopped flow temp stayed constant at 34C but return dropped to 25C in 5 minutes.
This was turned off by thermostat so I donāt know what WL mode would do here if I set 2093 to 2 or 3 or 4.
I believe when the water pump is off then the heatpump canāt have information about if it should start heat again or not and this is biggest mystery for me which Iām pretty sure you can clear up
I believe in UFH systems with big water volume this could work but how this can work for radiators.Thanks!
Hey @SarahH I think Iāve understood the logic of WL and #2093 but Iām either stupid or something is broken. I found few interesting things and something I canāt explain.
Thing is this is the chart from yesterday run when Iāve enabled #2093 mode 4 this means after compressor off the pump is running for 3 minutes, then 7 minutes off, 3 minutes on and so onā¦ But this didnāt happen! After compressor went off the water pump was running for exactly 1 minute and then it stopped! But why ? This must be wrong. So it happened that when pump was running the LWT and RWT equaled and both sit at 36C. Fine, but then the pump stopped and RWT started to drop of course so 1 minute and 30 second after the water pump stopped HP started compressor again.
I ask why itās working like that and not according #2093 setting ? Then for the cycle from 0:36 to 1:19 Iāve enabled #2093 - 3 so the water pump should be ON all the time after thermo off but again it is ignored. This is killing me because I guess because of this behavior of water pump the pump starts cycle way to fast. There is 2m:30s because it starts to re-heat againā¦.
Do you have an idea why #2093 is ignored? Iām using terminals 1 and 6 for the water pump with PWM regulation but canāt believe this could be an issue. But I believe if the pump would stay on according #2093 the pump would not start that fast. I donāt know the exact logic when pump start to reheat again.
What is also interesting that if WL mode is used (#2093 other than 1) the HP does not modulate to 14Hz! It never goes below 20Hz and tries to keep target temp as long as possible. But from the chart logic is not clear. You can see that first run was very long over 3h:30m until the HP decided to stop. It was oscillating around 40.5 LWT. But the next cycle was much shorter only 45 minutes until it stopped it for 2m:30s and started again and that cycle was 43 minutes. Whatās the logic behind, why the first cycle was that long and other that short. Then Iāve turned the pump off overnight and it started at 5:00 a.m. and that cycle was again long 3 hours and then again shorter one.
I donāt understand this pump at all 
Iām not sure this is correct, I believe the default hysteresis (without #1061) is target ā target +1/2C.
I have different values for this from different manuals (see images below) which may determine whether it is 1 or 2.
So if your target water temp is 30, thermo will turn off at 31/32, then turn back on again at 30.
#1061 adds a lower hysteresis. I have mine set to 3.5. So if the target LWT is 30, thermo turns off at 32 (which is have validated with monitoring), and it turns back on when LWT drops to 26.5 (which I have also validated). This gives me a total hysteresis of 5.5C which seems to work quite nicely for eliminating cycling. The wider your dt, the higher you will need to set #1061, as LWT drops to RWT (and a little lower thanks to flash cooling ) during the 1st pump 3min pump run on.
I have #1063 set to 0 (I think), which I think applies the same logic as if set to 4, which you can see here:
This steadily and evenly brings down the LWT without having the pump running constantly, though my pump only draws around 30W at my fixed flow speed, so itās not the end of the world if it were to.
@Michal_S You could try powering the MIM off and back on to see if changes to 2093 take affect. From memory, this is a thing.
Your compressor turns back on immediately because you do not have #1061, so LWT immediately drops below the lower hysteresis value (target LWT) and thermo is turned back on straight away. You could see if you can detect the start of cycling and turn heat off for 1 hour maybe.
1 Like
Iāve tried this out for the last few days. At the start of the peak time, 16:00, Iāve scheduled Heat with LWT set to 15. Then at 17:00 I schedule Auto to turn back on.
Here is a graph of this working:
The pump runs for 3 mins every 10 mins, to keep warmer water from the house flowing through the outdoor unit. It hasnāt dropped cool enough for the heat pump to need to run an AF cycle, but I canāt see how this isnāt going to prevent it from happening. After 3 hours, RWT drops from 25.2C to 20.5C.
Even if it drops below freezing outside, I canāt see LWT dropping to 15C, as the indoor temp isnāt going to drop that low, and thatās what is keeping the water warm.
Problem solved? Partially Iād say. A good solution that doesnāt require any external hardware or monitoring.
Hi Jake, this is quite interesting. Seems my pump does not work that at all?
Youāve mentioned I should try to restart MIM controller. You mean by this switch to turn it off and back on ?
Iāve tried it so letās see if the pump behaves according #2093 now.
Just for confirmation is this the mode where the pump should be always on ?
Btw, you can see here I canāt see #106x at all on my pump. What exactly do i need to enable it ? #105x is the last item there.
If I have donāt have that setting whatās the default hysteresis ? I can see itās roughly 0.5 - 1C above target when compressor shut down compressor but then immediately my flow drops to 36C and after a minute or so it starts again. I think this is wrong why ? On your chart here I can see your flow temp is around 28C, then it stops a pump kick where LWT? temp drops to like 22C ? So there is around 5-6C hysteresis on yours ?
