@derek-m okay, it would appear that you've worked it out! 

The values appear to be as I listed above. I am now on 2091 #2

It stopped for 2min 30 second. 

I have the water out temp for wl2 Fcu set to 20-32 but running -1.5 on the main screen

Outdoor temp is set at low 20 and high -3.0

So with my basic understanding the system will run until lwt is 30.5, run for a further 1 min then shut off then cut back in once it drops below 30.5? 

Thanks 

Now running on for 6.5 minutes off for 2.5 minutes. Inverter pump runs at 100% for full 6.5 minutes. 

2091, 2 and 3 are all set at #2 when set at #3 heat pump runs constantly. Inverter pump runs 100% all the time. 

Should I still have room stats set at 21 as a back stop whilst doing this?

Could the Teva Out sensor be causing any issues with this? Where would it be located? On the PCB on the UVC or on the outside unit (heat pump)? 

Posted by: @craig1980

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@derek-m okay, it would appear that you've worked it out! 

The values appear to be as I listed above. I am now on 2091 #2

It stopped for 2min 30 second. 

I have the water out temp for wl2 Fcu set to 20-32 but running -1.5 on the main screen

Outdoor temp is set at low 20 and high -3.0

So with my basic understanding the system will run until lwt is 30.5, run for a further 1 min then shut off then cut back in once it drops below 30.5? 

Thanks 

Not quite correct.

With your above settings, the WL slope is from a LWT of 20C at an ambient of 20C, up to a LWT of 32C at an ambient of -3C. So if the ambient air temperature is say 6C, the WL value would be 27.3C - 1.5C offset = 25.8C. Because there is also normally inbuilt hysteresis within the controller operation, such that if the calculated WL value is 25.8C, the compressor may run until the LWT reaches 25.8C + 5C = 30.8C, and then the compressor does not restart until the LWT falls to 25.8C - 5C = 20.8C. The hysteresis values will probably be adjustable. I will have a look in the field settings and see if I can identify them. Does the manual for your equipment have any identification code so that I can ensure that we are both looking at the same document?

Try setting the offset to 0 and let the indoor air temperature stabilise over a number of hours. Then see how your system performs.

If you find that the indoor temperature is too high or too low, then calculate new WL values.

@derek-m okay. The user manual I stumbled across online as the fitters said they don't supply it as it's too complicated. 🙄

The other manuals were supplied with the pump. Pics below. 

I've set the offset to 0 now. Thanks for the explanation, that makes it clearer. 

Posted by: @craig1980

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Now running on for 6.5 minutes off for 2.5 minutes. Inverter pump runs at 100% for full 6.5 minutes. 

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2091, 2 and 3 are all set at #2 when set at #3 heat pump runs constantly. Inverter pump runs 100% all the time. 

Should I still have room stats set at 21 as a back stop whilst doing this?

Could the Teva Out sensor be causing any issues with this? Where would it be located? On the PCB on the UVC or on the outside unit (heat pump)? 

Because you only desire an indoor temperature of 18C, you can leave your thermostats set to 21C.

The inverter pump to which the message refers is one or the other of your water pumps, but because they do not have PWM control capability, the controller cannot control the pump speed. The 100% reading is speed at which the controller would be operating the pump if it could.

The fact that the Teva_out indication is showing a permanent -50C reading would indicate to me that there is a problem. As far as I am aware the temperature sensor is located on the pipework around the Plate Heat Exchanger (PHE), which is in the outside unit.

I think that Hughf also has a Samsung heat pump, maybe he would be kind enough to provide a set of readings from his system for comparison?

Out of curiosity how do you calculate the water law? Working backwards I can see how you might have got to 27 but not 27.3. I'm just trying to get my head around it. 

Also, system seems to struggle to get the LWT to anything more than 28.8. It has sat at that for a fair while now. I'm guessing it should be trying to reach 32 now I've set it to 0 offset. It hasn't shut off once now I've changed the offset. Constantly running at 0.9kw. 

@craig1980

The video below shows where the Teva_out sensor is located and how it can be tested.

GOOGLE.COM "https://www.google.com/search?q=eva+out+sensor+samsung&rlz=1C1OPRB_enGB514GB552&oq=eva_out&aqs=chrome.6.69i57j0i30l9.20483j0j7&sourceid=chrome&ie=UTF-8#fpstate=ive&vld=cid:2302f360,vid:fAVb9Ed4NcQ"

@derek-m thanks, I'll check that tomorrow.

Posted by: @craig1980

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Out of curiosity how do you calculate the water law? Working backwards I can see how you might have got to 27 but not 27.3. I'm just trying to get my head around it. 

Also, system seems to struggle to get the LWT to anything more than 28.8. It has sat at that for a fair while now. I'm guessing it should be trying to reach 32 now I've set it to 0 offset. It hasn't shut off once now I've changed the offset. Constantly running at 0.9kw. 

To calculate the required LWT based upon the WL slope settings.

The ambient air temperature in your case is 20C minus -3C = 23C.

The set LWT range is 32C minus 20C = 12C.

Dividing 12 by 23 gives the expected increase or decrease in LWT for each 1C change in ambient temperature.

So the required LWT at 5C would be given by:-

12/23 = 0.522C approximately. The difference in the ambient temperature between 20C and 5C is 15C. This gives a temperature difference in LWT of  15 x 0.522 = 7.83C.

Adding the 7.83C to the 20C LWT at 20C ambient, gives a required LWT of 27.83C. Any offset value will add to or subtract from this value.

If possible allow your system to continue running and monitor the system temperatures along with the room temperatures. If the room temperatures start to get too warm then try an offset of say -1C.

I cannot understand why your system may be struggling to produce such low LWT values.

@derek-m it's okay, I was being impatient. It's hitting the temps fine I believe. I'm out for the night so I'll check again tomorrow. Thanks

@derek-m so, I've been away for around 24 hours. System is running for around 20 hours a day according to operation time on the wired remote. COP of 3.4. 

Outside temp is currently 3.4 degrees, LWT is 29.0, indoor on wired remote is 22 and room stats read 18.5.

House is comfortable and not too warm but that seems like a lot of power used for the day. That includes heating the hot water once during off peak time. Is it a lot or is that quite normal for a heat pump? I'm still on the same weather curve with 0 set back on the heat screen. 

I'll change to the other value in 2091 for 24 hours as I'm away again in a bit and see what happens. 

Ive not been here in daylight to check the Teva sensor yet. 

So I'm now set on 2091, 2 and 3 at #3

I'll report back tomorrow to see how that affects run time etc.