LG Therma V mono block Air Source Heat Pump

[DannyEvs]

@Hogboon Ive got an LG heat pump as well, same controller. I was using the AI function which I believe uses weather compensation to optimise flow temperature, leaving it on 24 hours a day.  Seemed to work at first but then temperatures in the house began to fluctuate and now I have it timed via a thermostat. Regarding the controller - if you want to access the settings, you need to go to the settings icon, hold down the up arrow, then type in the software version (4 digits - should be visible on the controller).  This takes you into the settings and near the bottom of the list is a log of the last 50 or so boiler functions - I think if there were any errors you would see them in this list. 

[DannyEvs]

On 11/01/2021 at 20:14, Arvyd said:

After 1,5 year of my experience with this monoblock when I thought that AI function is unusable at all, seems that I was wrong.

Guys I suggest You try AI function with seasonal settings in PPT file I added, and try set pump pre/ower run to another settings (my 2/2). Sensors air+ water. Seems heatpump working continuesly, I newer seen it before, without shuttdowns. The electricity consuption is wery interesting too.

Its just another way ?. Its short expierence, but maybe its right way.

Waiting for yours expierence if you try it.

 

Hi @Arvyd Id be interested in seeing this PPT if you can reissue it?  The AI worked for me at first but then struggled and now I have switched to a time schedule based on thermostat.  But I prefer the concept of AI

[Chris Bottomley]

Hi,

I have been playing around with the AI mode on our 12Kw LG Therma V Monobloc installed in may last year.  We have a radiator system so really need flow temperaures in the 40 to 50 degree range to confortably heat the house and provide a reasonable response time.

 

As seems to be usual with these systems the information provided was neglible- just "leave it on all the time" set in normal heating mode.  This resulted in an unacceptably heavy power consumption so I started playing arund with teh AI mode.  From an internet search the installer settings available from the remote control unit relevant to the AI mode seem to be:

Outdoor Temp for Auto Mode

Indoor Temp for Auto Mode

LWT for Auto Mode

 

Changing the LWT for Auto Mode setting from Min 20 and Max 50 to Min 34 and Max 50 seems to shift the AI mode operating temperature up to a more comfortable level.  I assume that this setting defines the lower and upper flow temperature settings for the AI mode.  My guess is that the indoor and out door temperature settings define maximum and minimum limits used by the AI algorithm.

 

Can anyone confirm whether I am on the right track and give any better information on setting the parameters for theAI mode?

 

[Hogboon]

Thanks DannyEvs for the info about the LG remote controller and apologies for slow response but my eye has been off the ball. I had hoped to be back with a triumphant shout of “good news.” However, nothing has changed since I last posted apart from the weather being a degree or two colder.

I can find no log of boiler functions on my LG Remote Controller. Presumably I access ‘settings’ via the cogwheel icon? Doing so takes me to a ‘Settings’ screen with 3 sub-sections:

FUNCTION: >Low noise or >Wi-fi Pairing

USER: >Language or >Temp. unit or >Screen saver or >LCD brightness or >Date or >Time or >Summer Time or >Password or >Schedule or >Theme or >Auto return or >System reboot

SERVICE: >Service contact or >Model info or >RMC version [in my case 3.05.5a (Master) or >Open Source Licence

Am I looking in the right place or do you think my controller does not output data on functions and errors?

LG sent a couple of blokes here for a ‘look see’ in the course of which they connected a laptop to the heat pump. If I did the same might I be able to access any data via Excel or csv? or do you think I would need special software?

Good job we’ve got a fireplace!

 

Ref. Chris Bottomley [hail fellow Somersetter!] being a retired hammerman I am somewhat in the dark about LWT, AI and most other heating shorthand, but our heatpump came with the LG 'Remote Controller' which as far as I can see is all we'd need but in addition we have a 'Nest' Thermostat which appears to over-ride the room heating part of the Remote Controller.

 

The Nest thing is a massively over-priced but pretty toy as far as I am concerned. When you tell it you want the house heating to come on at 08:00 at 18ºC you have the option of setting it to do just that; start the pump at 08:00. This means that if the house temp. has dropped overnight to say 16º it will be an hour or two [or all day in our case!] before the house is up to the requried temp. It's default setting however seems to assume that it is the temperature rather than the time which is salient, so in the above scenario it will calculate from the prevailing indoor and outdoor temperatures what time it needs to start the heatpump in order to have the house heated to 18º by or at 08:00. In my case this means the heatpump fires up aroun 04:00 - which is a right pain.   

[Chris Bottomley]

Hogboon,

We have a similar setup to you except that we have a Honeywell programmable thermostat controlling the heating.  This overides the room temperature sensor in the remote controller.  We have the heating set to on all the time and just drop the temperature 1 deg overnight.  The Honeywell thermostat is not as clever as the Nest, the heating comes on when you set it, it doesn't try and anticipate the demanded temperature by starting the heating early.  Our house has a similar thermal inertia to yours- on an average winter day it takes an hour or two for the ASHP to raise the remperature by 1 degree, over the recent cold spell it could take most of the day to come up one degree.  This is with the radiator circuit running at around 45deg. 

 

When it was installed we had the system running at 50 deg for the ASHP heating flow, the house was warm enough but the electricity consumption was rather frightening.  At the moment I am trying to find the best compromise between radiator temperature and electricity consumption- hence the playing around with the AI/ Auto mode on the LG remote controller rather than using a fixed heating circuit temperature.  My understanding is that the AI mode uses an internal algorithm to adjust the ASHP temperature based on the outside and internal air temperatures.  Basically I think that as the outside temperature goes down the ASHP flow temperature is increased to compensate, the internal house temperature may also have some influence on the flow temperature.  Unfortunately with the way our system is configured the ASHP flow temperature was in the range of 30 to 40 deg which was too low for our radiator installation- I am currently trying to tweak the settings to give a higher maximum temperature.

 

With regard to DannEvs post, as he says the data logging information is accessible through the remote controller but you have to be in the Installer Setting mode to get to it. To get to this you need to have the Setting icon (cogwheel) selected.  With the "cogwheel" highlighted press and hold the up arrow key ( ^ ) for three seconds.  An enter password screen with 4 boxes will be displayed.  The password is the software version number, in your case I think this is 3055.  Use the arrow keys to enter this and you should then be presented a long list of menu options.  The data logging oprion is near the bottom of the list.

 

This displays a list of around 50 lines of the latest data logged at what looks like about 12 minute intervals.  The data appears to be:

-  Date/ Time

-  Operation Mode

-  Heating set temperature

-  ASHP in/ out temperatures

-  Hot water operation/ target and current temperatures

-  ODU- I don't know what this is, nothing is registered on my system.

-  Error- again blank

 

My guess is that with a laptop plugged into the ASHP the installers will get a more detailed and a much longer history of data.

 

A caveat on the above-  I do not have much information on the operation of the LG Therma V system so much of the above has been worked out using a general control systems and engineering knowledge background based on the operation manual and observing the operation of the system.  I have had no support from the company that installed the system- lesson learnt there.  If you do go into the installer menu do not change anything unless you know what you are doing and make sure that you have a record of the original values as installed so that you can go back to them.

 

[ReedRichards]

Hello all, I have had a 12 kW LG Therma V for a little over 2 months now

 

It ran for less than 24 hours and then stopped with a CH14 error.  The installer came back, concluded that a filter inside the unit was blocked and fixed it.  It has not misbehaved since.

 

Hogboon, I think the raised finger to the lips symbol probably indicates "Quiet Mode" - because the symbol is saying "Shhh".

 

I have experimented with the (undocumented) AI mode but it just resulted in a failure to reach the set temperature.  This does not happen if I control the outlet water temperature.  I have my own room thermostat and I find it hard to believe that the AI mode can work with anything other than the LG-supplied room thermostat because I don't believe you can control intelligently without knowing the difference between the actual room temperature and the desired room temperature.

 

When the heat pump gets a call for heat, it waits about two minutes then turns on its pump.  It then runs for about 4 to 5 minutes before it turns on the 'Outdoor Unit' to supply heat.  If the room temperature is near the desired temperature the thermostat might decide momentarily that the room was hot enough and then the cycle would have to start all over again.  I ended up telling my thermostat that it was controlling an oil boiler which then limits the number cycles per hour to 3.  Even so, most of the time the heat pump cycles; I have not yet worked-out how to get it to supply a lower level of heat more continuously.         

[SteamyTea]

34 minutes ago, ReedRichards said:

  I have my own room thermostat and I find it hard to believe that the AI mode can work with anything other than the LG-supplied room thermostat because I don't believe you can control intelligently without knowing the difference between the actual room temperature and the desired room temperature.

I can.

It can use historical usage patterns.

 

35 minutes ago, ReedRichards said:

ended up telling my thermostat that it was controlling an oil boiler which then limits the number cycles per hour to 3.  Even so, most of the time the heat pump cycles; I have not yet worked-out how to get it to supply a lower level of heat more continuously.    

Does your system have a buffer tank?

[ReedRichards]

3 hours ago, SteamyTea said:

I can.

It can use historical usage patterns.

 

Does your system have a buffer tank?

You're going to have to explain "historical usage patterns" in some detail if you want me to understand what you mean.

 

There is a buffer tank built in to the base of the hot water cylinder.

[ReedRichards]

@SteamyTea  seems to have gone off the boil, or off to boil a kettle, but I have some thoughts for @Chris Bottomley

 

During the recent cold spell my Therma V was using up to 48 kWh per day running at a 50 C flow temperature.  But it managed to keep the house at the desired temperatures and took two to three hours to raise the temperature by 1 degree C.  Now that the weather has turned mild I have been experimenting with the flow temperature and 40 C seems fine and will raise the temperature after the nighttime setback at a similar rate.  I am now using about 25 kWh per day.  In the installer settings you have the choice of 3 settings for the temperature sensor, Air/Water/Air+Water.  My guess is that you need to set Air + Water if you want the AI mode to pay attention to the room air temperature.  My installer set this setting to Water to avoid unwanted interaction between the LG room thermostat and my own (Drayton Wiser) programmer. 

 

[SteamyTea]

Half term week and being servicing holiday makers.  Strange as they are not meant to be be here, but shall take their cash.

And you need to select the name from the @ list to send a notification.

 

So you wanted to know about how historical records can be used to control temperature.

 

Basically it looks at the time that the system runs, and at what temperature it runs up to.  Then using a combination of convergence and divergence, a system can 'learn' what is required.

[ReedRichards]

When I tried to use the AI mode it failed to reach the room temperature I had set.  But then the system had been in operation less than two months so perhaps it had not had enough learning time?  How long do you think it needs to build up decent historical records?

 

Also you can set AI with numbers (-5 through 0 to +5, I think).  What do the numbers mean?

 

And a general query: do you have your own programmer?  If so: can you use it to time the hot water?  Is the "Select temperature sensor" set to Water or Air + Water.  In my case my programmer cannot time the hot water because it was set up that way but I don't see why it should be a problem.  And Select temperature sensor is set to Water.  I can see this will avoid conflicts with my programmer but it must limit the scope for intelligent control. 

[Chris Bottomley]

@ReedRichards I don't know about the relevance historical records and how the AI mode works on the LG ASHP, hence my original post to see if anyone else had information. I'm basically trying to work out how best to set it up by making changes and looking at the impact on the flow temperature data and house temperature change response time.

 

I have used the number settings on the AI mode, I'm not sure the numbers have any meaning they may be just increments as on a volume control e.g. turn the volume up to 10 (or 11 if you are Spinal Tap) .  From memory setting the AI mode to +5 increased the flow temperature by around 4 degrees, going to -5 had the opposite effect.  This was when the system was running at flow temperatures in the mid to high 30s at the AI 0 setting.  If the operating temperature range is different the AI settings may have less or more effect

 

Our system is set up to use the internal hot water temperature sensor and an external Honeywell programmable thermostat.  The hot water is programmed as schedules in the LG controller to come on around mid day when there is the best chance of output from the solar panels.  The heating schedule are controlled by the Honeywell themostat, it is essentially on all the time but we drop the demanded temperature overnight. 

 

Our controller Select Temperature Setting is set to Water I assume as we have the external temperature stat but I could be wrong.  I haven't been able to find any firm information as to what this setting means.  I wouldn't want to use the temperature sensor in the LG controller as it has been installed in a location in the house that get quite warm when it is sunny.  The Honeywell stat is in a more representative position for the overall house temperature.

[ReedRichards]

@Chris Bottomley I'm glad you came back; I think we users all need to work together to find out how to get the best performance out of our heat pumps.

 

My system is set up the same way as yours but this means that I cannot turn on the hot water remotely after I have been away, although my central heating programmer has the capability to do this.  As with you, I drop the demanded temperature overnight.  At the moment my hot water is on all the time except overnight.  I will try to use the immersion heater on sunny days as that heater has a power requirement (3 kW) that is better matched to my solar panel output.

 

The water setting is the target temperature for the inlet water.  My system was set-up for this to be 50 C but I have been running at 40 C since the weather turned warmer.  I suspect that I have dome manually what the AI mode tries to do automatically. 

 

The heat pump has an outdoor temperature sensor but does not report what it reads.  Perhaps a software/firmware update could fix that?  My software version is 3.05.6a .

[ProDave]

8 hours ago, ReedRichards said:

My system is set up the same way as yours but this means that I cannot turn on the hot water remotely after I have been away, although my central heating programmer has the capability to do this.

 

I "solved" this puzzle early on in this thread.

 

Using the LG supplied temperature probe in a pocket in the hot water tank.

 

The probe is just a simple thermistor, a resistor that changes value with temperature.

What i did was insert the contacts of a changeover relay into the circuit.  So when you want the hot water "on" the relay normally open contact connects to the temperature probe.  The normally closed contact connects to a fixed resistor, I chose the value by trial and error and ended up with a 560 ohm resistor.  This fixed 560 ohm resistor makes the heat pump think the hot water temperature is 85 degrees so it turns off the hot water heating believing it to be satisfied.

 

The relay in my case has a 240V coil and is controlled by a normal central heating time clock.  When Hot water is off at the time clock, the fixed resistor is in circuit so the heat pump thinks the hat water is satisfied and hot water heating is off.  When the time clock comes on, the relay energises and puts the temperature probe into circuit, so the heat pump will heat the water if it is below the set temperature.

 

It seemed a bit of a fudge to me and like you I was disappointed there was no proper way to remotely turn hot water on or off, but it works and it does the job.

[ReedRichards]

@ProDave, that's an ingenious solution but also emphasises how easy it would have been for LG to have done something themselves.  How did you mount the relay?  When I read your initial posts I was focusing on the CH14 error as I had experience that very briefly until a filter was changed.   

[ProDave]

8 hours ago, ReedRichards said:

@ProDave, that's an ingenious solution but also emphasises how easy it would have been for LG to have done something themselves.  How did you mount the relay?  When I read your initial posts I was focusing on the CH14 error as I had experience that very briefly until a filter was changed.   

I just sat the relay on a convenient ledge and cable tied it there so it could not fall off.

[ReedRichards]

@ProDave, May I ask what relay you actually used (make and model)? 

 

I seem to remember seeing something inside the big box on the side to which the thermostat is wired that looked a bit like a relay (a large component inside a transparent box).  At the time I was looking to see how I could correct an error by the installing electrician who had wired the immersion heater in series with my own time switch instead of in parallel.  This was when I had the CH14 error and found I could not even use the immersion heater when the heat pump was not wanting to play ball.  That is corrected now.  

[ProDave]

Any small relay with screw terminals will do.  The ones I used were made by Finder and I bought them from CPC but when I looked another time I could no longer find them.

[Chris Bottomley]

@ReedRichards I don't have any facility for remote operation of the system- being an ex-software engineer I like to keep things simple as I know that you can rapidly end up wasting time trying to get different systems working together.  Not really something I have had to worry about as we have essentially been in lockdown since the ASHP was installed☹️

Like you I dont have any access to the LG temperature sensor, my external temperature readings come from the RHI Metering and Monitoring Service Package data we had installed however I'm pretty sure that there is no external temperature sensor in this, the readings probably come from the local weather station, Yeovilton in our case.

[ReedRichards]

@Chris Bottomley, yes my Drayton Wiser programmer will tell me the minimum and maximum temperatures for each day without the benefit of a temperature sensor.  Possibly it uses this information for its "Comfort Mode" which tries to reach the desired temperature (increase) at the time set for that increase to occur.  Do you feel you are benefiting from the RHI Monitoring?  I just opted for the minimum requirement, which is metering. 

[Chris Bottomley]

@ReedRichards Interesting question about the benefit from the metering, we have the MMSP monitoring package but the supplier failed to support it so we don't get any money back from the RHI or the support that we should get from the supplier.  On the plus side I think the supplier possibly got his pricing wrong in our benefit.  The MMSP monitoring provides 2 minute readings of heat pump energy consumed and output, efficiency, flow temperature, internal and external air temperature (although as I note above I believe the external air temperature is from a local weather station not the data logger) and also immersion heater consumption.  I also have logs of the solar panel output and can get can get downloaded data from the smart meter.  What I do not have and would be very useful is heating and hot water demand logs so I can work out whether the heat pump is supplying radiators or hot water.  Heating circuit flow temperature would be useful as would an actual outside air temperature reading for our location.

 

Do we benefit from the extra monitoring?   It has been useful to a certain extent in tuning the heat pump operation, for example you can see the energy used if the heat pump is just maintaining the temperature in the heating buffer tank when there is no heat demand.  You can also see the correlation between the outside air temperature and the heating flow temperature which helps when trying to set the controller parameters for better efficiency.  Due to the way the heat pump works you don't get nice smooth plots (see the attached screenshot) so you need to do a lot of eyeball estimation to work out average values and the impact of changes to the system parameters.  I have done some manipulation on the data to smooth it and provide average values but I'm still working on the best way to use the data.  In conclusion I think that we may get enough help out of the metering to reduce the consumption of the heat pump to get payback for the additional cost of the metering in 4 to 5 years as compared to what I would have been able to work out from just the basic energy consumption figures.

 

[SteamyTea]

8 hours ago, Chris Bottomley said:

I'm still working on the best way to use the data

Frequency distributions are probably the way to go i.e. mean flow temperatures by different temperature differences.  There should be two peaks then, one for the space heating and the other for the DHW (assuming the flow temps are different).

Edited March 8, 2021 by SteamyTea

[ReedRichards]

Just FYI, this is my entire house electricity consumption for 7th March.  The highest peaks are mostly heating the hot water but could be cooking.

Edited March 8, 2021 by ReedRichards

[ReedRichards]

Question: Can you operate your immersion heater independently of the heat pump?

 

I had some teething troubles with my heat pump when it was first installed and the error code on the controller meant that I lost all control.  I wanted hot water but found that the switch for my immersion heater had been wired in series with the internal switch so I had to do some emergency rewiring (then get the electrician back to fix this). Now I am reading of another instance of someone in the same situation.  Surely it should be standard practice to ensure that the immersion heater can be used independently?

[Gav_P]

33 minutes ago, ReedRichards said:

Question: Can you operate your immersion heater independently of the heat pump?

 

I had some teething troubles with my heat pump when it was first installed and the error code on the controller meant that I lost all control.  I wanted hot water but found that the switch for my immersion heater had been wired in series with the internal switch so I had to do some emergency rewiring (then get the electrician back to fix this). Now I am reading of another instance of someone in the same situation.  Surely it should be standard practice to ensure that the immersion heater can be used independently?

I assume you mean the immersion heater in the actual hot water cylinder... if so, the yes. 
 

If you mean the one integrated with the heat pump (seems to be an LG thing), I don’t have one of those.