Hi @glyn.hudson
Sorry to be a bother. I have just had a Gen 7 (AE080CXYDEK/EU) installed with OEM level 3 monitoring (Emoncms - app view) and am also having trouble getting PWM to work (among other things). This was my installers first Samsung so I don’t think he’ll be any the wiser and he can’t get back to me for a few weeks anyway. He did leave his MIM-C02N here though, but before I bother plugging it in, I was wondering if you’d have any idea whether a firmware update would help me out.
I’m not familiar with the Gen7 firmware, however I think it’s unlikely that then Gen7 firmware would have this issue. Have you checked the wiring? Check the PWM connections are connected and check the pump is a PWM enabled pump. You could post some photos on this thread?
Also check that PWM is enabled, FSV #4051 for Inverter Pump which is Samsung’s name for the circulator pump should be set to use (100%).
It looks like your flow rate does vary, do you have multiple zones? Could this flow rate be varying due to zone valve changes? Your flow rate does seem to vary abruptly, which doesn’t look like normal PWM operation e.g
Have you submitted this system to https://heatpumpmonitor.org/ ?
Hi @glyn.hudson.
Here are some photos.
I’ve tried every possible combination on the PWM wiring side. I even tried a different 2 wire PWM cable incase that somehow worked. I’ve tried the way it’s shown in your diagram, which I think is from Midsummer, and I’ve tried Brown top, Black bottom, as shown in the Samsung training handout from my installer, and everything else. You’ll see that I currently have it wired onto the switched live B8 (so it isn’t permanently on), but I have been doing my testing on B6. I have checked #4051, and tried turning this off and on to see if this worked.
The step changes in the flow rates are from me changing the fixed flow speed on the pump itself to try and maintain dt5, it has a few different settings.
In the first few days I must have had alot of air/debris but that seems to have sorted itself out now. I also topped the pressure up to 1.7bar as it had dropped to 0.6 bar.
It is submitted and published to https://heatpumpmonitor.org/system/view?id=470.
I’ve done some further testing with multimeters borrowed from work today, not sure if this is unusual behaviour or not, but with #4051 set to max 70% and the pwm cable unplugged from the pump, I’m getting a 30% signal at 1KHz which sounds promising, but as soon as I plug the PWM cable into the pump the signal disappears. I filmed a video to help show what’s happened.
Mmm your PWM connections look correct. B6 is the usual connection for the primary pump, but it sounds like you’re aware of this.
The oscilloscope reading shows that the heat pump is correctly outputting a PWM signal, maybe your pump needs to be put into PWM mode to accept the signal? My Grundfos PWM pump doesn’t have any manual controls, it’s PWM only so I didn’t have to worry about this
It looks like you have a hybrid pump, have you tried setting it into a PWM profile mode:
From:
Looking at the pictures further up the thread, it’s a UPS3 not a UPM3
According to the data sheet it should automatically detect the PWM signal when present. This is of interest to me since I will shortly be trying to PWM a UPS3.
Looking at the PWM input circuitry, on the pump side it is an opto with a current limit. So it would be quite likely that when you connect it up the voltage would appear to collapse (depends on driver circuit in heat pump) because it is essentially a current driven input.
According to the data sheet it should automatically detect the PWM signal when present. This is of interest to me since I will shortly be trying to PWM a UPS3.
This is my understanding too, but never been able to get it into PWM mode. Let me know how you get on.
I spoke to my installer about it and he’s ordered a UPM4 (which is a variant of what is fitted in the integrated units) which I’m hoping I can fit today. I was also not getting enough flow rate from the UPS3, so it made little sense trying to diagnose this any further.
He asked me to clean the filter too, which did get me from 9lpm to 14lpm on CH and 15lpm on DHW, but still a way off the 20lpm I need. Flow rate has started dropping again, so I probably need to regularly clean the filter until I can have the whole system flushed in a couple of weeks.
Still no luck with PWM. Fitted the UPM4 tonight and it’s still just running at fixed speed. Once, when i tried a different pwm cable the speed did start to jump up and down very quickly (changing speeds in less than a second). It also didn’t stop doing this when driven with a 0% signal from the controller. I haven’t been able to replicate this since turning the controller off.
The PWM light on the pump does light up (see image below) but does not flash to say that a PWM signal is established. Starting to think this may now be a Samsung issue, and not a pump issue.
Any words of wisdom from anyone would be greatly appreciated.
Also still only getting 16-17lpm on max speed, the data sheets for each pump seem to suggest I should be seeing a much bigger increase in speed.
Oh dear, sorry to hear. This is exactly what I experienced with my Gen6. I updated the firmware on the heat pump which fixed the issue. But I struggle to believe that this bug has been carried over to the Gen7. Try contacting Samsung technical support, they are quite helpful [email protected]
If you’re only seeing 16-17 lpm at max speed, then this could be the reason why your pump is not modulating? The flow rate might not need to go any lower if the heat pump is working hard. What size is your HP in terms of kW output? Do you have any monitoring on this heat pump?
The flow rate is determined by the hydraulic resistance of your heating circuit. If your pipework is restrictive and or the circ pump is undersized, then the flow rate will be low, even when the circ pump is running at maximum speed.
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I too am interested in firmware upgrade on my GEN7 5kw, at least knowing if there’s any available. I also have observed almost no change in the PWM (I have the integrated unit). But when I manually cast the PWM I want, then the MIM applies it and the UPM4 respects it.
So I guess it could be related to the firmware.
Best regards,
What do you mean by manually casting the PWM?
My installer is coming back round next week. He has the tools needed to upgrade the firmware so I’ll speak to him about it.
I found out that writing to the 0x40C4 modbus register can “limit” the PWM. I use it to play and observe the CoP depending on it.
That would be wonderful, I guess it’s merely a USB RS485 adapter, or a sdcard (I know both methods work for firmware upgrade).
BR
Thanks @glyn.hudson.
I might give the email a try, but my installer is coming back on the 10th so I’ll ask him to try a firmware update first.
It’s an 8KW heat pump, my calculated heat loss is 5 - 6 KW.
Monitoring here:
https://emoncms.org/app/view?name=MyHeatpump&readkey=53646698bd10ba801ad47516e7e4a0bc
Any changes to flow rate were from me restricting the flow manually or changing the speed profile on the old pump, something that’s not possible on the new pump. I’m looking forward for the next 12 hours, getting the average outside temp and setting my flow rate according to a spreadsheet that someone else has shared on here (sorry I can’t remember who) that I’ve modified to include ideal flow rates.
My installer should also be installing some low head-loss radiator valves when he returns, so hopefully that opens things up a bit. Aside that that, it’s completely open, 1 TRV on our bedroom radiator as the missus can’t sleep if it’s too warm and my tinkering can’t interfere with that. Some radiators are closed down quite a lot as they’re too big for the rooms (compared to other radiators in the house).
I’ve borrowed the multi-meter and oscilloscope from work again to do more investigating tonight.
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You need an S-NET dongle to update the FW:
and SNET PRO software: https://www.samsunghvac.com/Software-Downloads/SNET-Pro2
You can see what firmware versions are available via the Samsung Partner Portal: GlobalPartner
My FW updated is detailed in this post below, YMMV. I have a Gen6, so FW could be totally different for Gen7, check the hardware versions carefully before updating!
@glyn.hudson I think you have some of us at a bit of a disadvantage, maybe because you qualify for a Business Account, hence can access the Partner Portal.
For those of us who can’t, even if they have a (borrowed 
) MIM-C02N, how can they check that their FW is up to date? Your link above referred to DB91-02103B and DB91-02091B, but I don’t see these mentioned in my C02N outputs (I see DB91-02450A 220706 Main Micom and DB82-07081A 220622 EEPROM vers, which look different to yours).
In words of one syllable, where do I find my current FW versions, and the latest versions?
PS I’m not all that happy with the S-Net Pro2 software, which seems to mangle some of the MIM-E03EN data, like not showing compressor current with believable values (and calling the units degC rather than amps). I’ve asked Samsung UK Tech Helpline for help but still await a response…)
Sarah
Glad you found this useful. I’ve added min flow rate to my original sheet, with a option for glycol.
@SarahH I’ve just managed to register myself a business account using my personal email and now have access to quite a few resources. I have found firmware for my MIM-E03EN but nothing under the outdoor unit product code.
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I have bought a cheap PWM controller from amazon and now have PWM working on the pump, though not automatically controlled from the heatpump.
Until the controller PWM starts working, i still have to look at the weather forecast and set the PWM accordingly. I have been through and recorded the flow rate for each PWM setting so it’s at least quicker and easier. The pump speed seems to only vary with 7% duty cycle increments.
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Can anyone not sign up? I don’t think they verified a business name.
The current FW version is listed on SNET:
To update the FW you need to use the MIM ribbon cable, which is different to the normal way to connect the MIM for data logging. I think there’s also a switch on the MIM which needs to be adjusted.
TBH I feel like I don’t know enough about Samsung FW to advise anyone to update it. I think it’s quite easy to brick the HP if the wrong FW is uploaded. There’s also no way I could see to roll back the FW and Samsung don’t provide change logs. The whole process is quite opaque and could easily end in disaster!
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Nice! It’s the indoor unit that I updated which fixed the PWM, I think it’s the indoor unit which is responsible for running the circ pump and generating the PWM.
As far as I recall, my indoor unit is MIME03CN (DB91-02103B) I updated the firmware to 220614 which seemed to fix my PWM issue.
But as I mentioned before, I have a Gen6 so YMMV