@derek-m 

Power, energy and flow rate  metering:

1) Power within the water system

I use a Sharky to measure the power carried by the water supply to my Radiators.

The Readings are fed via a European M-Bus interface to my PC.

Note that the POWER is constant at 410 Watts  with the Energy controlled by the Run Time .

The Thermostat supplies , and modulates  Run Time.

When shorted, the Run time reverts to an UN-modulated state..

2) Flow rate Measurements:

The Sharky also provides the water flow rate to the Radiators:

Notice that the Power and flow rate are identical curves using different scales!

3) Electrical Power.

The Short term Electrical energy is measured by a CT Transformer attached to Mains supply to the entire Heat Pump.

Here showing the power with the Thermostat shorted followed by a period with the Thermostat connected.

4) Electrical Energy

Electrical Energy is measured by a second CT Transformer attached to the Entire Heat Pump.

The Display shows Power,Energy, and Power Factor.

5) Samsung Generated and consumed energy.

The Excellent Samsung displays the daily Energy Consumption and Generation.

The Power drop out yesterday :

occurred when I removed the Thermostat Short without increasing the Water Law [+15:25] coordinates to [+15:+35] .

When I returned after 1700 the house was cold , remaining cold despite increasing the Water Law offset to 3 C . 

I switched on a 600 W electric fire to increase the Temperature in a reasonable time.

410 Watts at a Run Time of 7 minutes would take a very long time to heat my living room!

Posted by: @iaack

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I have always thought the volumiser should be plumbed in series with the secondary heat exchanger and not in parallel with it (as shown in @iantelescope diagram above). Am I missing something?

No you are not missing something, this has already been highlighted on a number of occassions.

@iantelescope thats really helpful thanks.  Remember that 410 Watts is multiplied by COP to get the heat delivered.  At this time of year 1-2kW is all you need to keep the house at a constant temperature.  The run time will be longer during a reheat mode as you saw when you first changed the wc parameters a couple of days ago.  It will reduce as the house approaches temperature.

Please can you confirm that you are now doing all of the following

   a. Put the WC coordinates BACK to the ones @derek-m gave you (15:25; -5:45) 

   b. Take the buffer out of circuit

   c. Dont touch the 'outing' mode or switch the heat pump off unless you go away for more than a day.  It will cost you money to do so!  It needs to be on 24x7

   d. Leave the thermostat shorted out

   e.  Set all TRVs to their maximum (you can leave the one in one bedroom turned down if its otherwise too warm to sleep)

This will give us another period of stable operation to assess.

If you are not doing this please confirm what you are doing

@iantelescope

So what you label 'Power W' is actually thermal energy, though I do find it rather strange that it is constant at 410W. Is the Sharky correctly configured?

I don’t believe any of the data being recorded. There is something far wrong if only generating 400 watts from heat pump as no heat pump can modulate down to that level. 
also electrical input power same or similar range. 

@iantelescope your recent data is really helpful thanks.  Please remember that the run time will be longer during a reheat mode as you saw when you first changed the wc parameters a couple of days ago.  It will reduce as the house approaches temperature.  However the basic principle of operating a heat pump efficiently is to keep it on 24*7 or thereabouts.  (Actually this is true of boilers also but that's a whole other discussion which only a part of the industry has acknowledged and which I can explain if you are interested.)

Please can you confirm that you are now doing all of the following

   a. Put the WC coordinates BACK to the ones @derek-m gave you (15:25; -5:45) 

   b. Take the buffer out of circuit

   c. Dont touch the 'outing' mode or switch the heat pump off unless you go away for more than a day.  It will cost you money to do so!  It needs to be on 24x7

   d. Leave the thermostat shorted out

   e.  Set all TRVs to their maximum (you can leave the one in one bedroom turned down if its otherwise too warm to sleep)

This will give us another period of stable operation to assess.

If you are not doing this please confirm what you are doing

@jamespa 

I Stand Corrected!

Honestly, after two and half years I did not believe that the Heat Pump Could or should be  run from a Water Law graph with coordinates of [+15:25] !

Well it looks as if I was wrong......my apologies James and Derek.

I have , reluctantly , maintained the Water Law coordinates of [+15:+25] , this despite innumerable warnings that I must religiously follow the NIC / MCS commandment to use [+15:35].

The 35/45/50  C requirement being that displayed on the MCS "Design and Sizing" Documentation as the "design Water Temperature".

All of my MCS "Design" documentation give the performance starting at 35 C with the NIC demanding that I use the "design Temperature " of 50 C for this setting.

My current Water Temperature output .

My current Return Water Temperature

And, most surprising of all ......my current Delta_T on the Radiator , Secondary Pipe circuit.

The Delta_T is unaffected, at 3 to 4 C. !!

Wait

My room  Temperature, here  relies on the Heat Pump , using the Water Law Curve and attempting to produce a similar Radiator characteristic curve.

Only time will tell how the Water Law follows the Radiator characteristic .

Let me gather more evidence.

.

Thanks and noted. The MCS recommended values are a sop to the British desire to feel hot radiators with the objective of minimising call outs.  They have nothing to do with sensible operation, they are installer protection.  MCS does not exist to help the end customer, it exists to help the customers of MCS which are installers.

So we can interpret your output and so you have the maximum chance of success please can you confirm that you have done ALL of the following:

   a. Put the WC coordinates BACK to the ones @derek-m gave you (15:25; -5:45) 

   b. Take the buffer out of circuit

   c. Dont touch the 'outing' mode or switch the heat pump off unless you go away for more than a day.  It will cost you money to do so!  It needs to be on 24x7

   d. Leave the thermostat shorted out

   e.  Set all TRVs to their maximum (you can leave the one in one bedroom turned down if its otherwise too warm to sleep)

@jamespa 

Yes James.

I am currently:

1) using the [+15:+25] and [-5:45] Water Law Defining Coordinates.

2) No using the Buffer.

3) Not using "outing" mode. Actually I have not used outing for over 18 months, having discovered the effect of the Time taken to subsequently reach a proper room Temperature in a reasonable time.

4) Shorting the Thermostat .

5) Leaving the TRV's open. In practice, I have not , so far,  been able to adjust the TRV's with no adjustment leeway or flexibility being available.

I have , however become aware of the falling outside Temperature  causing my body temperature to fall.

I have added 1 C to the Water Law Offset Screen to compensate, with my Room Temperature now rising to 22C .

I appear to need an increased room temperature as the temperature falls, now 13.1 C.

ian

@iantelescope

The initial WC curve settings are a starting point, so if the room temperature starts to fall then add 1C to the setting at the cold end, change the 45C to 46C.

When posting graphs could you please add the number of the sensor that has provided the data. Have you had any success in monitoring IAT and OAT?

@jamespa 

James , I am reminded of a farcical incident where a "NIC Engineer" accompanied by "Two Engineers" from my "installer" visited my house to "inspect" my Heat Pump.

The NIC Engineer insisted that my Heat Pump operation be "demonstrated by being set to operate at the stated, MCS, design Water Temperature".

The trio of "engineers" then attempted to set the Water Temperature on my  Heat Pump with the Water Temperature controlled by the Water Law.

They did not succeed!.

After 30 minutes, total silence descended as the Heat Pump objected ..............displaying innumerable Warning messages.

The trio departed some 2 hours later, silently  leaving with  the Heat Pump switched OFF.................................. and Not working but issuing innumerable warning messages!

I reset the Heat Pump removing the faulty Field bit settings.

Posted by: @iantelescope

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@jamespa 

Yes James.

I am currently:

1) using the [+15:+25] and [-5:45] Water Law Defining Coordinates.

2) No using the Buffer.

3) Not using "outing" mode. Actually I have not used outing for over 18 months, having discovered the effect of the Time taken to subsequently reach a proper room Temperature in a reasonable time.

4) Shorting the Thermostat .

5) Leaving the TRV's open. In practice, I have not , so far,  been able to adjust the TRV's with no adjustment leeway or flexibility being available.

 

I have , however become aware of the falling outside Temperature  causing my body temperature to fall.

I have added 1 C to the Water Law Offset Screen to compensate, with my Room Temperature now rising to 22C .

I appear to need an increased room temperature as the temperature falls, now 13.1 C.

 

ian

  

Excellent  Please be patient, this is going to take some weeks to get to the optimum settings and you will only achieve that by staying the course.

Posted by: @iantelescope

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I have , however become aware of the falling outside Temperature  causing my body temperature to fall.

I have added 1 C to the Water Law Offset Screen to compensate, with my Room Temperature now rising to 22C .

I appear to need an increased room temperature as the temperature falls, now 13.1 C.

ian

  

Posted by: @derek-m

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The initial WC curve settings are a starting point, so if the room temperature starts to fall then add 1C to the setting at the cold end, change the 45C to 46C.

When posting graphs could you please add the number of the sensor that has provided the data. Have you had any success in monitoring IAT and OAT?

In terms of adjusting the WC curve, thats going to take time and be iterative.  The house may take 24hours to stabilise after any change so there is a strong risk that you overshoot.  You will need to be patient and resist the temptation to fiddle for as long as you safely can, given that you need to keep your body temperature up.

Im now going to suggest a different approch to that which @derek-m has suggested, so perhaps he can comment - because he may be approaching this particular challenge in a different, but equally (or more) valid, way. 

• With an OAT of 13C I would adjust the warm end of the WC curve only, and leave the cold end where it is.  You are essentially trying to get it right at two points, cold and warm, or put another way you are trying to adjust the slope and the offset.  Unfortunately the weather wont oblige by remaining at either, hence the challenge, but if the weather is very close to the warm point then then logic suggests you should adjust this (which you can view as the offset), and likewise if the OAT is closer to the cold point then logic says you should adjust that (which you can view as the slope).  Once we have some more data we can speak about how to deal with middle which is where the weather is most of the time.
• Currently the weather is very close to the warm point so I would bump that up by say half to one degree, and leave the cold point where it is.  The weather is getting warmer over the next few days so it should be a good time to tune the warm point fairly well.  Once that's right we can play with the cold point, as the weather gets colder.  We can, at that point, also do some calculations on what would be expected, which will inform the adjustments.
• That said your approach of adding 1C to the offset screen is equally valid as a way of getting a handle on the correct parameters, which can then be programmed into the water law itself so you dont have to fiddle manually.  Take notes!  This, btw, is what Homely does for you, or auto adaption in heat pumps that have that feature (Samsung doesn't).

Tomorrow please can you report what happens overnight but also the readings of Sen3 and Sen7 once everything is stable.  This tells us the temperature loss across the heat exchanger which in turn tells us whether we need to be concerned about it or not (at warm OATs).  And as @derek-m says if you can plot and report IAT and/or OAT then that would also be very helpful indeed.