Meter Readings Panic and Electricity Costs

[canalsiderenovation]

6 minutes ago, AliG said:

48 looks to malice the DHW temperature which is OK. You can see it is hot water in the top left hand corner.

 

However, Water Law seems to be Samsung's catchy name for weather compensation. This is switched on and it looks to me like your UFH flow temp is running at 56C currently (water outlet on the water law page). I am not sure how to switch it off and just set a flow temp. I tried reading the manual but it is not easy going.

 

The Water Law setting that you have at 0 I think adjusts relative to whatever temperature the weather compensation has been programmed to give out. I believe from Google that this can be set between -5 and +5, but you can see what it will let you set. Thus if you set it to -5C then your flow temp should drop by 5C.

 

Reading the manual it would be quite involved to change the weather compensation settings. It looks to me like they have been set with a very high flow temperature when it is cold outside as at the moment. There are options to set a range of outside temperatures and then a range of flow temperatures dependent on this variable. You can see them on p27, the unit seems to have been set somewhat higher than the default temperatures.

 

The manual has to be the most poorly user friendly manual.

 

I did some adjusting. So when I went in just now it was zero.

 

 

I then adjusted the temperature to minus 5 and got this.

 

 

And you are right it only goes +5 and -5 it won't go any more or below.

 

 

[AliG]

The flow temperature will go up and down depending on the outside temp. It seems a lot lower than it was earlier.

 

I think quite a few people don’t like the weather compensation option because of this but someone with an ASHP can probably answer better.

 

Nevertheless setting it at -5 will have it running a bit cooler which should mean a better COP and is a start.

[canalsiderenovation]

2 minutes ago, AliG said:

The flow temperature will go up and down depending on the outside temp. It seems a lot lower than it was earlier.

 

Could that be because we reduced our thermostats to 19 degrees?

 

2 minutes ago, AliG said:

Nevertheless setting it at -5 will have it running a bit cooler which should mean a better COP and is a start.

 

I'll set it at -5 thank you.

 

Have to say at 19 degrees it isn't particularly warm now and I can definitely tell the difference!

[SteamyTea]

I am finding all this fascinating.

Seems that the biggest problems people have (apart from incorrect sizing), is setting up the flow  temperatures.

This is probably non-intuitive as a number of things happen in a heat pump at the same time, and it is all a balancing act.

 

Just remember that temperature is not energy delivered.

I may have to sleep in this and try and sketch what is happening in the morning (just had my busiest night since October and feeling tired).

[canalsiderenovation]

2 minutes ago, SteamyTea said:

I am finding all this fascinating

 

I'm finding it stressful!

 

Thank you everyone for your help. It's kept me occupied all night and distracted and not continually checking my emails for my Covid results....

[Dave Jones]

13 hours ago, AliG said:

Much as this cannot be done in this case.

 

If you ignore environmental concerns, electricity is considerably more expensive than gas. On my tariff I am paying 2.14p per kWh for gas and 14.29p per kWh for electricity, so electricity is 6.6x the price of gas. Thus with an 85% efficient gas boiler and an average COP of 3.3 an ASHP would be around 70% more expensive for heating than gas. People are perhaps being sold ASHPs as a cheaper way to heat their homes. They are absolutely not cheaper than a gas boiler if you have mains gas available.

 

However, you get a generous RHI payment for an ASHP and you save on putting a gas supply in and on having two standing charges. So this evens things out, especially the RHI which will make the ASHP cheaper for the first 7 years.

 

 

This is the problem with ASHP. I've decided not to use them anymore as they are  expensive  crap compared to a combi. I wont compromise on limitless proper hot water, not the luke warm stuff that comes out a ASHP,  and a combi doesn't play up when you really need them when its bloody freeezing outside.

 

They are the betamax video equivalent of the heating market and a better solution needs to be found, I believe Worcester boche are working on one. 

[AliG]

I have had a further read of the manual.

 

P11 gives instructions on showing the ASHP's energy usage. perhaps you can use this to see how much electricity it has used in the last week.

 

 

 

You should be able to turn off "Water Law" from the zone page and change it to Heat mode where you can set the Water Outlet temperature. If it is locked and you cannot do this, p13 of the manual describes how to remove the function lock that may have been switched on by the installer.

 

Before messing around with it and changing lots of settings, I would like some input from other owners of ASHP as to whether they think you would be better to run in weather compensation mode or with a constant flow temperature. It could be that you should run weather compensation mode but the installers have set the flow temperatures too high in that mode. This will be even more true once your EWI is installed and you need less heat input.

 

Looking at the documentation provided for expected energy use, which is pretty close to my guess earlier on, you are using more than I would expect for heating by maybe 20 or 30%. This is not drastic and could be due to sub optimal set up, the lack of EWI and quirky cold weather conditions.

 

There is what seems to be an error to me in the expected energy use chart, I think it is just the way it is  set to averages over the year whilst January will give the worst performance. It suggests the house needs 3000kWh in January, which was my guess, so call it 100kWh per day. It then applies a the seasonal performance factor which is a COP of 3.63 to get just over 800kWh of electricity usage in January or around 27kWh per day. But with an outside temperature of just above 0 and a flow of around 50 you can see from the Ecodan chart I sourced that the COP would be closer to 2.2, so ASHP energy usage would be more like 45kWh per day. This is an average so 50+ would definitely be possible on a cold day. Reducing the flow to the high 40s might cut energy usage by 10-15% as the COP would rise to the high 2s, but the 25kWh per day shown on the chart is quite misleading.

[ProDave]

I don't use weather compensation on mine.  I simply don't see the need.  I have by experiment found the lowest flow temperature that works all year reliably and stick to that.  The room thermostats turn the heating off when the rooms get to temperature, what more is actually needed.

 

In theory I could use weather compensation to run the flow temperature to the UFH lower when it is less cold and I can see that it would work but only once set up properly, and to be honest I can see it taking a whole winter to get it right and getting a temperature curve that works at all outside temperatures.  I think this is a common problem, the installer takes a bit of a wild guess at how to set the temperatures and as long as it heats up his job is done.  He is not going to keep visiting and adjusting to optomise it just to make it slightly more eficcient.

 

What is sad is there are not clear and simple instructions in the manual that would allow the user to fine tune the weather compensation themselves.

[SteamyTea]

6 minutes ago, ProDave said:

I don't use weather compensation on mine.  I simply don't see the need. 

Does weather compensation work best when the ASHP is in constant use?

Or does it just use predetermined parameters to try and deliver the designated amount of energy i.e. -5°C outside, Flow Temp 40°C, -2°C outside, Flow Temp 37°C (or whatever)

[ProDave]

9 minutes ago, SteamyTea said:

Does weather compensation work best when the ASHP is in constant use?

Or does it just use predetermined parameters to try and deliver the designated amount of energy i.e. -5°C outside, Flow Temp 40°C, -2°C outside, Flow Temp 37°C (or whatever)

It is trying (if implemented properly) to use the minimum temperature that works at all times.

 

e.g with mine, I know the temperature needed for the UFH in deep winter, where we are now.  At that UFH temperature it takes 3-4 hours in the morning for the UFH to make up the temperature lost over night when it has been off.  When it is less cold it will make up the nights loss very much quicker.

 

All I need is a "end of season" data point, the minimum temperature it can work at in the spring or autumn.  Perhaps when spring comes before we turn the heating off, I will experiment with lower temperatures and see just how low you can go and still have UFH that works in that milder weather.  With that data I could then implement a compensation curve * and try it next winter and see how much if any it reduces running costs.

 

^ they call it a weather compensation "curve" but it is just 2 data points and a straight line between them, nothing "curvy" about it

 

[TonyT]

17 minutes ago, ProDave said:

I don't use weather compensation on mine.  I simply don't see the need.  I have by experiment found the lowest flow temperature that works all year reliably and stick to that.  The room thermostats turn the heating off when the rooms get to temperature, what more is actually needed.

 

In theory I could use weather compensation to run the flow temperature to the UFH lower when it is less cold and I can see that it would work but only once set up properly, and to be honest I can see it taking a whole winter to get it right and getting a temperature curve that works at all outside temperatures.  I think this is a common problem, the installer takes a bit of a wild guess at how to set the temperatures and as long as it heats up his job is done.  He is not going to keep visiting and adjusting to optomise it just to make it slightly more eficcient.

 

What is sad is there are not clear and simple instructions in the manual that would allow the user to fine tune the weather compensation themselves.

 
Agree 100% with this statement.

my weather compensation on gas boiler turned off for just this reason

[canalsiderenovation]

Ok so woke this morning and after changing that setting to -5 this is the screen:

 

I also found the energy setting info:

 

Consumption:

Will be interesting to see what happens for the next week now.

 

Operation:

 

Generation:

 

I haven't messed with any other settings yet. 

Edited January 16, 2021 by canalsiderenovation

[canalsiderenovation]

1 hour ago, AliG said:

You should be able to turn off "Water Law" from the zone page and change it to Heat mode where you can set the Water Outlet temperature. If it is locked and you cannot do this, p13 of the manual describes how to remove the function lock that may have been switched on by the installer.

 

There is no option to turn off the water law I can see and page 13 only lets me access the basic settings. I can't seem to access the installation menu as Alto must have blocked this. On the plus I spoke to them yesterday and they took the meter readings for the immersion/heat pump and I'll be checking in with them in a week and asking them about adjusting the flow rate and turning off this water law.

[TonyT]

The installer may have locked the installer menu so they get call out, it happens with other equipment so may be possible with this unit?

 

dies it appear on the installer manual( may find a copy on the web)

[canalsiderenovation]

35 minutes ago, TonyT said:

The installer may have locked the installer menu so they get call out, it happens with other equipment so may be possible with this unit?

 

dies it appear on the installer manual( may find a copy on the web)

 

I have the installation menu and there is nothing on there. Alto should be able to talk me through it if nothing else.

[canalsiderenovation]

Right, managed to access the installers menu. Lots of options. Any suggestions... @AliG 

 

I've got the manual but to be honest it's far more complicated than the actual screen.

 

 

 

 

 

 

[AliG]

52 minutes ago, TonyT said:

The installer may have locked the installer menu so they get call out

 

Alarm companies etc love to do this. I have the manager code for our alarm and without this would have had to call them numerous times to change settings.

 

We just had a gate controller put in. They said if I emailed them phone numbers etc they would programme the gate. I got the manual out and did it myself, if I didn't do this how would I ever change the settings after it is installed. I think there must be a lot of cases where people simply stop using things because they can't change the settings.

 

[SteamyTea]

15 hours ago, canalsiderenovation said:

Is 0202 a passcode

Just need to find out where to punch it in.

[canalsiderenovation]

Just now, SteamyTea said:

Is 0202 a passcode

Just need to find out where to punch it in.

 

Got it, I actually wrote it down ? you have to hold the ^ and down button at the same time for about 5 seconds and then it prompts you. That's how I accessed the menus above. If you then don't touch anything for 2 seconds it locks again!

[AliG]

20** are the Water Law settings.

 

You could look here to see what curve they have programmed.

 

2021 is the max Water Out temp

2022 is the min Water Out temp

 

2011 is the outside temperature where the max temp is hit

2012 is the outside temperature where the min temp is hit

 

 

I would guess that they have considerably raised the default temperatures. If you think about it, they don't want hassle after the system is installed. People will notice a lot faster that their house doesn't get hot than they are using more electricity than expected and so the tendency is probably to set flow temps too high.

 

As ASHP owners have said, theoretically weather compensation would cut your bills. Ideally you are always using the lowest flow temp required to heat the house which maximises your COP, but this would need careful setting. However, you use a lot more energy when it is very cold than when it is say 7-10C, thus setting a fixed flow temp that works when it is cold is probably the easiest way to start. As @ProDave said you could then set this as the flow temp at the low end of the weather compensation curve and a lower temp at the high end of the curve but this would require a lot of experimentation.

 

Edited - 2041 is UFH/Radiator setting not WaterLaw off or on

 

Now that you are in installer mode you should be able to change the mode from Water Law to Heat as shown on P18. First I would be interested to know what the flow tempsthey have set in 2021 and 2022 are.

 

Edited January 16, 2021 by AliG

[AliG]

This just popped up on my screen. Imagine their UFH bills-

 

[canalsiderenovation]

Okey dokey....here is the info from the water law menus. Priority is getting our energy consumption down at the moment.

 

 

 

 

[PeterW]

So at -2°C it’s trying to give you 45°C water into the floor. What is the mixer valve on the UFH set at ..??

 

I would be looking at -5°C High and 10°C low, and 35/42 as the values. 

[Temp]

20 hours ago, canalsiderenovation said:

We haven't got our external wall insulation yet

 

I wouldn't worry too much then. Wait for that to go in before making system changes.

[AliG]

TBH those settings look OK.

 

I am not clear why the flow was 56C the other day if it is set at 45C max. Maybe it was heating hot water at the time.

 

Considering those settings I would just set the Water Law setting to -3C which would theoretically give a maximum flow of 42C and set your thermostat at 21C and see what happens.

 

As @Temp says it may be that your EWI will make a big difference and you have an underinsulated house during a cold period.

 

It looks like the ASHP was averaging just over 50kWh a day before the 16th when you were fiddling with it. It is not that far above the 45 a day I was estimating. That suggests that you are using 20odd a day for other electricity which is quite a bit higher than the 300 units a months you said you were using before the renovation. You might want to investigate that.

 

Maybe the 300 was average over a year and you are using more because it is darker, or maybe you have treated yourself to an 85inch TV over Christmas. It does seem a bit high. I don't think our electricity usage is that much higher in winter than summer.