LG Therma V mono block Air Source Heat Pump

[ReedRichards]

11 hours ago, Chris Bottomley said:

...I have managed to reduce the ASHP consumption by around 20% by tweaking temperatures and schedules over my second year of ownership with little impact on comfort....  

 

Any tips?

[Chris Bottomley]

Steamy Tea:

Regarding electricity demand:

• The total house demand: logged from the house smart meter by optical pulse counting over a two minute time period- kWh.
• ASHP and immersion electricity usage - measured by meters, meter readings read approximately every two minutes by the MMSP monitoring system installed with the ASHP- kWh.
• Solar generation: logged from the solar export meter by optical pulse counting over a two minute time period- kWh

ReedRichards:

The reference point for the 20% reduction was the ASHP as left by the installers: running unsheduled for heating at 45deg and hot water at 55deg, house temperature demand 20deg.  Since then I have arrived at the following through various experiments:

• Hot water on a timer schedule to heat first thing in the morning. I may change this to late afternoon/ early evening to get most benefit from residual solar energy in the summer being diverted to the immersion.  I know that this is less efficient in real world terms but it will end up cheaper for me due to the way that the FIT scheme works.
• House demand temperature reduced to the minimum we can live with (19deg) during the day and dropped by 0.5deg overnight.  The heating is controlled by a wireless thermostat, we will move this to the coldest room when needed.  We also use the short term temperature boost facility.
• Adjusting the thermostat to give longer on periods for the ASHP.
• Setting the ASHP to AI mode at the zero setting- the ASHP running between 30 to 40 deg.  We were running it at AI +5 last year for a period but the default setting seems to heat the house reasonably well although the radiators barely feel warm.

Essentially I followed the usual advice- to cut down on the heating cost reduce the house temperature to the minimum you can live with.

 

The house is an extended detached 1960s chalet bungalow insulated as well as possible without extensive works. It has a 175m2 floor area and a combined heating and hot water energy requirement of about 20,000kWh according to our last EPC.  The measured electricity usage of the 12kW ASHP was around 5,500kWh for the last year (February 21 to January 22), for the first full year of use (July 19 to June 21) the usage was around 7,100kWh.  The caveats are this winter has been significantly milder here than last year and as there are only two of us in a relatively large house the heating in unused rooms is minimal.

[Ronny]

 I know it is a long time since i posted here, but i now have figures for a full year of running the heat pump. To save you looking back, the house is ex council built in 1937.  Double glazed , with cavity and attic insulation no doubt done by the council before being bought by the previous owner. Total of 8 radiators. 2 bedrooms. LG Therma V 7kw mono block.

Octopus go at 5p and 12.93p

1082 units @.05 =      £54.10

5799 units @ .1293 = £889.71

Daily charge 

25p x 365                   £91.25

Total for the year =    £1035.06   No gas supply since installing heat pump,

I don`t have any records of what i was paying for the dual fuel , but it was probably  a bit less than this.

I have just fitted 16 solar panels with 5.2kw of batteries, so it will be interesting to see the difference  in the next year. I hope this is of interest

[HughF]

On 07/04/2022 at 14:58, Ronny said:

 I know it is a long time since i posted here, but i now have figures for a full year of running the heat pump. To save you looking back, the house is ex council built in 1937.  Double glazed , with cavity and attic insulation no doubt done by the council before being bought by the previous owner. Total of 8 radiators. 2 bedrooms. LG Therma V 7kw mono block.

Octopus go at 5p and 12.93p

1082 units @.05 =      £54.10

5799 units @ .1293 = £889.71

Daily charge 

25p x 365                   £91.25

Total for the year =    £1035.06   No gas supply since installing heat pump,

I don`t have any records of what i was paying for the dual fuel , but it was probably  a bit less than this.

I have just fitted 16 solar panels with 5.2kw of batteries, so it will be interesting to see the difference  in the next year. I hope this is of interest

Very interesting, thanks for the information.

 

Those unit prices though, what things were like back in times of old

[MikeSharp01]

On 07/04/2022 at 14:58, Ronny said:

Total of 8 radiators. 2 bedrooms. LG Therma V 7kw mono block.

Very interesting numbers - Did you get any impression for the average COP of the Heat Pump.

[Ronny]

14 hours ago, HughF said:

Very interesting, thanks for the information.

 

Those unit prices though, what things were like back in times of old

I don`t know how but i have fixed again until 17/02/23. at same rates. Happy days.

Edited April 9, 2022 by Ronny
add information.

[Ronny]

5 hours ago, MikeSharp01 said:

Very interesting numbers - Did you get any impression for the average COP of the Heat Pump.

I would not know how to work out the COP. I am far too old to have this type of information. Tell me how in simple terms and i will try.

[ReedRichards]

I live in a 1980 timber-framed bungalow with 4 bedrooms, 16 radiators.  I have had a monobloc 12 kW Therma V for 16 months.

 

My heat pump used 5330 kWh in the 12 months from 31/3/21 to 31/3/22.

 

Hitherto I had an oil combi boiler, which used 1936 litres of oil in a 367 day period.  I calculate that would be 17935 kW h per year if my boiler (installed in 2012) achieved 90% efficiency.

 

Since I had the heat pump I have had a hot water cylinder and that has enabled me to heat it via electricity from my solar panels supplied to the immersion heater on sunny days for about 7 months of the year.  Power to the immersion heater is not metered.

 

It's impossible for me to know what CoP I achieve but it must be in the vicinity of 3.

 

      

[HughF]

@ProDave given the current good value of the LG Therma V units (£2700 inc vat for a 9kW unit: https://www.tradesparky.com/solarsparky/heating/air-source-heat-pumps/lg-hm091mru44-therma-v-s-9kw-heat-pump), would you say they represent a good ASHP option, given that they are a known brand and not the usual generic chinese offering?

 

If that price includes a controller, that's a decent deal.

[ProDave]

Yes and only £1897 plus VAT for the 5kW that i have.  You end up with it ex VAT on a new build.

[HughF]

47 minutes ago, ProDave said:

Yes and only £1897 plus VAT for the 5kW that i have.  You end up with it ex VAT on a new build.

Thanks for the input, it seems like too good a deal to pass up at those prices.

 

Unfortunately our heat loss (at present insulation levels) means we need around 6.9-7.1kW otherwise I'd be going for the smaller unit. That's almost on price parity with a good quality system boiler.

[ReedRichards]

Remember to factor-in the cost of the DHW cylinder with the large surface area coil that a heat pump needs.  If heat pump prices are falling then the relative cost of the DHW tank is increasing.

[HughF]

Looking back at the LG range again as it appears from watching every YouTube video I can find that the new colour programmer/controller is the nicest on the market in terms of UI design. And the way the weather comp can easily be nudged up and down if the rooms feel a little cold or hot would suit the way we like to operate. I don’t fancy the idea of an additional controller or room stat.
 

And the price is hard to ignore.

[Transition]

Greetings All,

Checking in as a new LG Therma V user. Living in Utrecht (center of the Netherlands). Reading the topics in this forum, I noticed users in GB are struggling with the same questions as in NL. Hope we can exchange experiences.

We installed the LG Therma V LG-HM163M-U33 in March this year. Trying to get it to work, we found out that the LG user and install manual, are far form complete and even partially incorrect ;-(

Apart from the LG, we're using  Vaillant aroSTOR VWL B 200-5 for our tap water and solar-panels 8.400 Watt-peak to reduce the energy consumption.

Therefor I signed up and hope to exchange experiences and contribute to this forum and especially the LG topics.

Hope my English is fair enough to make myself understandable. If I'm talking rubbish, please let me now and I will reformulate my text.

Kind regards, Charlie

[Transition]

May I use the opportunity to ask help on a question I have? I'm struggling to get the LG to heat up to the desired temperature. Both air and water.

We use our LG in combination with low temperature radiators, so no underfloor heating here.

From the earlier posts in this topic, I understand there is a cohesion between the parameters (1) "Outdoor temp. for auto mode", (2) "Indoor air temp. for auto mode" and (3) "LWT for auto mode".

1: 0 and 19

2: 16 and 22

3: 30 and 45

I think it works in a way that if

the outdoor temp (1) is 0 water temp (3) should reach 45

the outdoor temp (1) is 19 water temp (3) is restricted to 30

 

If this is correct (and I really don't know, as the LG manual doesn't enlighten anything on this matter), why does LG stop heating at a water temp of 32 max?? And this was during some cold night already of 3 degrees.

 

And how is Indoor air temp. for auto mode (2) related to this all?

 

 

[Ronny]

1 hour ago, Transition said:

May I use the opportunity to ask help on a question I have? I'm struggling to get the LG to heat up to the desired temperature. Both air and water.

We use our LG in combination with low temperature radiators, so no underfloor heating here.

From the earlier posts in this topic, I understand there is a cohesion between the parameters (1) "Outdoor temp. for auto mode", (2) "Indoor air temp. for auto mode" and (3) "LWT for auto mode".

1: 0 and 19

2: 16 and 22

3: 30 and 45

I think it works in a way that if

the outdoor temp (1) is 0 water temp (3) should reach 45

the outdoor temp (1) is 19 water temp (3) is restricted to 30

 

If this is correct (and I really don't know, as the LG manual doesn't enlighten anything on this matter), why does LG stop heating at a water temp of 32 max?? And this was during some cold night already of 3 degrees.

 

And how is Indoor air temp. for auto mode (2) related to this all?

 

 

You have my sympathy in trying to understand the LG settings. Mine was installed in December 2020 and i am still experimenting with the settings. Thankfully, i am nearly 80, so i at least have the excuse of being old. There is plenty of people on the forum, who will be able to help you, and i will be interested in the reply`s as well. Here are the setting i am using which seem to work reasonably well. Air heating set temp 17  26.

Water heat set temp  34   47.

Outdoor temp auto mode   -5   27

Indoor temp auto mode   16   24

LWT   30   47

These settings are working fine at the moment though it is not that cold outside yet.

This is with the mode set at air plus water.  I will watch with interest to the reply`s from users who know what they are doing. 

[Transition]

On 23/10/2022 at 15:10, Ronny said:

You have my sympathy in trying to understand the LG settings. Mine was installed in December 2020 and i am still experimenting with the settings. Thankfully, i am nearly 80, so i at least have the excuse of being old. There is plenty of people on the forum, who will be able to help you, and i will be interested in the reply`s as well. Here are the setting i am using which seem to work reasonably well. Air heating set temp 17  26.

Water heat set temp  34   47.

Outdoor temp auto mode   -5   27

Indoor temp auto mode   16   24

LWT   30   47

These settings are working fine at the moment though it is not that cold outside yet.

This is with the mode set at air plus water.  I will watch with interest to the reply`s from users who know what they are doing. 

Thanks for sharing your settings. There are some equal settings, but also significantly different. What type of LG Heatpump do you have? We found out there are several differences in setting between U33, U34 and U44. The later models provide more configuration settings and also more information on flow e.g.

We're also running in air + water mode. Testing with both AI and manual (heating). Not sure what effect this has on the outcome yet.

 

At the moment it's to warm over here to do some test runs. Next Friday even 20+ degrees. But when temperatures drop, I will start testing again. I'll report my findings here!

[Ronny]

On 24/10/2022 at 17:05, Transition said:

Thanks for sharing your settings. There are some equal settings, but also significantly different. What type of LG Heatpump do you have? We found out there are several differences in setting between U33, U34 and U44. The later models provide more configuration settings and also more information on flow e.g.

We're also running in air + water mode. Testing with both AI and manual (heating). Not sure what effect this has on the outcome yet.

 

At the moment it's to warm over here to do some test runs. Next Friday even 20+ degrees. But when temperatures drop, I will start testing again. I'll report my findings here!

Sorry for the delay in replying. The heat pump is - 

LG Therma V 7kw HM071MU42.

[Transition]

On 27/10/2022 at 15:02, Ronny said:

Sorry for the delay in replying. The heat pump is - 

LG Therma V 7kw HM071MU42.

Looking at your LWT (30 and 47) and Outdoor temp auto mode (-5 and 27) settings; did the heat pump ever reach 45 C? As far as I understand now, this will only be the case if outdoor temperature is below -5. Don't know how cold it gets in County Durham, over here we need a higher water temperature. Do you use additional heating?

[Ronny]

1 hour ago, Transition said:

Looking at your LWT (30 and 47) and Outdoor temp auto mode (-5 and 27) settings; did the heat pump ever reach 45 C? As far as I understand now, this will only be the case if outdoor temperature is below -5. Don't know how cold it gets in County Durham, over here we need a higher water temperature. Do you use additional heating?

It has been relatively warm here so far this winter, and i am not sure what temperature the water gets to as i just let the system run and do it`s own thing. I will try tomorrow to see what temperature it is running at. You are correct with your understanding of the -5. I never use any additional heating. At the present time i am using about 10kwh a day and that includes charging the batteries during the cheap rate at night.

[ReedRichards]

My installer tells me 'Air + Water' gives you Load Compensation as well as Weather Compensation, although I have never found this documented anywhere.  As such you must use the LG controller/thermostat, not one supplied by a third party which will only allow on/off control.

[ReedRichards]

I have had a request for the Product and Installation Manual so I have split it into 3 parts to enable me to upload it.

 

LG Therma V Product and Installation Manual - the final part covering settings

93321262_ProductandInstallationTrainingMaterial_90-end.pdf

Edited October 30, 2022 by ReedRichards

[ReedRichards]

LG Therma V Product and Installation Manual - the middle part.

934772090_ProductandInstallationTrainingMaterial_44-89.pdf

[ReedRichards]

LG Therma V Product and Installation Manual - the first part.

1988709679_ProductandInstallationTrainingMaterial_1-43.pdf

[Transition]

10 hours ago, ReedRichards said:

My installer tells me 'Air + Water' gives you Load Compensation as well as Weather Compensation, although I have never found this documented anywhere.  As such you must use the LG controller/thermostat, not one supplied by a third party which will only allow on/off control.

You're right, have not found this in any documentation and I've read a few 😉

We've been experimenting with a third party thermostat (Google Nest). Downgrades the heat pump to an on/off system. Had hoped to solve a couple of issues (hysteresis -2/ +2, an easier way of setting room temperature and a more understandable response). In our situation it didn't bring what we had hoped.

In order to use the third party thermostat dip switch 8 has to be set to on and than certain settings are greyed out.

So back to the LG standard thermostat (PREMTB100).

 

@ReedRichards thank you for sharing the Product and Installation Manual!! Haven't seen this manual befor. I'm sure it will help in a better understanding.