Daikin problem

[Togfather]

Helo.

I am not a professional, just a householder. My hpouise is an old barn with very thick stone walls.

 

I had a Daikin Altherma 3 ystem fitted in the summer under the ECO4 system.

 

The installer has created 2 zones (upstairs and downstairs).

They also fitted new radiators , solar panels, and wall insulation throughout the house. I previously had oil fired heating and changed because the installer said an ASHP system would save me money.

Now we have snow and freezing temperatures outside, it seems that we have serious heating problems.

The setpoint is set to 39 degress, but the Daikin control panel shows an actual temperature of only 34 degrees. Does this indicate a fault with the system? I have emailed the installer and Daikin, but not redceived an answer.

The third party thermostats (one for each zone) are set to 15.5 degrees, but only 13.5 degrees is being achieved. The actual room temperatures are down as low as 11 degrees, whereas before the cold weather they were reaching a comfortable 17+ degrees.

The radiators have been bled and the pressure is fine at 1.4 bar.

 

So, our heating is not reaching comfortable levels any more, yet the cost has jumped astronomically to £29 a day (equivalent to over £800 a month) I am a pensioner (71) and cannot afford to pay that kind of money, and for a cold house to boot.

Can anyone advise on what action, if any, I should take?

If the tank temperature will not reach the setpoint, I am wondering if the unit may be the wrong size for my house. How can I tell?

 

Many thnaks and best wishes.

 

Tog 🙂

 

[sharpener]

40 minutes ago, Togfather said:

I had a Daikin Altherma 3 ystem fitted in the summer under the ECO4 system.

 

So it should still be under warranty. Pester the installers by phone until they come to look at it. If they won't, threaten to pursue them under the ECO4 redress scheme (though unfortunately others have said it is not very effective).

 

Many things could be wrong. But if the control panel is not showing any error codes it does point to the HP being undersized. The high running costs may be due to an auxiliary electric heater being switched on in the cold weather.

 

Tell us here how big your house is in sq m, what kind of wall insulation they fitted and what size/rated output the HP is. 75W per sq m is a very approximate rule of thumb requirement for a stone barn conversion (like mine), might be less with good insulation and good draught-proofing but doubt you would get it better than 50.

[richard_scotland]

Hi Tog

 

I have the same model of heatpump and it is working OK to heat our 200m2 house (a not particularly well insulated old cottage) to 20 deg, and is using about 55 kwh a day at the moment to do that (producing 160 kwh of heat). We also upgraded our radiators and pipework. 

 

1. what size in kw is your heat pump? we have the 12kw model which seems to be plenty big enough for us and works out at 60W per sq m 

 

2. does it usually reach the 39 degree set point when its not so cold? 

 

3. Our flow temperature is 43-44 degrees at the moment (-5 this morning), so I suspect 39 would be too low anyway at these temperatures, unless your house is very well insulated. Can you try turning the flow temperature up and see if the room temperatures improve? are the radiators warm at all to the touch? are you running weather compensation (flow temperatures vary with outside temperatures) or fixed?

 

4. we run our system with only a 1 degree setback at night - if yours is set to turn off overnight it might be that room temperatures have dropped too low and its struggling warm things up? 

 

You could use the Daikin menu system to go to Information>Sensors 

On ours this shows you more information about the actual flow temperature and also the flow rate etc which may be helpful. I think there is also a malfunction log in that menu which might be worth a look at. 

 

 

 

[JohnMo]

2 hours ago, Togfather said:

heating is not reaching comfortable levels

How are you operating? Is the temperature set point, always set or are you operating on a timer on and off?

 

Heat output will slowly ramp up the output temperature depending on the temperature the return water is at. So depending on water volume within the heating system can take a while to heat up. Trying to operate for short periods of time doesn't work for a heat pump.

[Togfather]

Hello.

 

No error codes shown, and we did have a Daikin sales engineer visit with the installer to check in December because I complained that the cost went up and the temperature went down. He said the system was set up OK and left the setpoint at 39 degrees. Now the installer and Daikin are not responding to my emails. Maybe I am just being a pest, but they told me it would save money, and it isn't.

 

The heat pump is 11KW ( EBLA 11 DAV 3)

All rooms except for kitchen and bathroom have insulation on external walls Plasterboard with polyurethane.

Floor area is 158 m2 and the output on the project form is stated as 12785.

The unit is fixed setpoint, not weather dependent.

The unit is on all the time and the thermostat is also on all the time (no timer)

I now have the thermostat set to 17 degrees, but it won't get there (13.5 right now)

The unit often makes loud noise, like car with choke on.

Unit does reach 39 degrees sometimes, but fluctates between 34 and 39 (I don't understand why this is)

Unit has auto defrost. Sometimes it dumps water to prevent freezing, and this requires radiators bleeding and topping up pressure to around 1.4 bar.

I have increased the setpoint to 43 degrees, but if it can't achieve 39, it doesn't seem logical that it will achieve 43.

Flow rate shows 21, and the flow switch (whatever that is) is marked as "off".

Heating is using around 100kw a day, but rooms are cold with thermostat only reaching 13.5 degrees.

 

Best wishes.

 

Tog 🙂

 

 

 

 

[richard_scotland]

19 minutes ago, Togfather said:

 

The unit is fixed setpoint, not weather dependent.

The unit is on all the time and the thermostat is also on all the time (no timer)

I now have the thermostat set to 17 degrees, but it won't get there (13.5 right now)

 

 

If its fixed then the flow temperature probably too low to keep your house wam for when its cold as it has been this last week - much better (and cheaper) to have it change flow temperature with the weather. This is something easy to set up yourself using the Daikin menu. I can look later at how you do this. We went to town with large radiators (quite a few K3), but we still needed 43 flow temperature this past week, you might need higher still if your radiators are fairly normal sized. Our design temperature was 55 degree flow at -3 outside (do you have this information anywhere?), but in practice we can run it cooler than that and be fine. 

23 minutes ago, Togfather said:

 

The heat pump is 11KW ( EBLA 11 DAV 3)

All rooms except for kitchen and bathroom have insulation on external walls Plasterboard with polyurethane.

Floor area is 158 m2 and the output on the project form is stated as 12785.

 

This suggests to me that the unit is probably powerful enough. As I said ours is 12 kw and is not operating at max output and keeping our 200m2 single story cottage, half of which has no insulation on the walls, to 20deg.

 

26 minutes ago, Togfather said:

 

The unit often makes loud noise, like car with choke on.

Unit does reach 39 degrees sometimes, but fluctates between 34 and 39 (I don't understand why this is)

Unit has auto defrost. Sometimes it dumps water to prevent freezing, and this requires radiators bleeding and topping up pressure to around 1.4 bar.

I have increased the setpoint to 43 degrees, but if it can't achieve 39, it doesn't seem logical that it will achieve 43.

Flow rate shows 21, and the flow switch (whatever that is) is marked as "off".

Heating is using around 100kw a day, but rooms are cold with thermostat only reaching 13.5 degrees.

 

Best wishes.

 

Tog 🙂

Our unit is mostly very quiet and never makes a noise like you describe, so I wonder if something is not correct here. Also, ours does occasionally 'whoosh' as part of a defrost cycle, but we never have to top up pressure and bleed radiators after this - the fact you have to top up the pressure frequently also suggests something is not quite correct with the pipework or system. 

 

when its not heating and its below a certain temperature outside ours does cycle the water in the system every 20 mins or so to prevent freezing - does yours do this? 

 

100kw a day also suggests it is using the backup heater a lot. our 12 kw unit has only been using 55-60kwh a day (it sometimes uses the backup heater for a few minutes at the start of a cycle but they soon switch off). When its milder we are using 20-30kwh a day. 

 

I would persist in trying to get the installer back to look at the system as it doesn't sound like its working as it should do. 

 

[sharpener]

42 minutes ago, Togfather said:

The heat pump is 11KW ( EBLA 11 DAV 3)

All rooms except for kitchen and bathroom have insulation on external walls Plasterboard with polyurethane.

Floor area is 158 m2 and the output on the project form is stated as 12785.

 

11 kW doesn't sound undersized for 158m2 with reasonable insulation. But am a bit puzzled why if they got a heat loss (?) of 12785 they specified a unit of only 11kW. What is the minimum outside design temp?

 

42 minutes ago, Togfather said:

The unit often makes loud noise, like car with choke on.

 

Shouldn't happen

 

43 minutes ago, Togfather said:

Unit has auto defrost. Sometimes it dumps water to prevent freezing, and this requires radiators bleeding and topping up pressure to around 1.4 bar.

 

So did they fit antifrost valves and are these what are dumping the water, and is it only under freezing conditions outside? If you get this frequently you would be better off with glycol to protect the system, but as this will slightly reduce the heat transfers it might be better to leave it until the performance issues are sorted out.

 

As per my earlier post emails are too easy to ignore. You need to escalate this within the Daikin hierarchy by phoning the regional manager etc.

 

Edit: I see @richard_scotland has just posted so there is a bit of overlap in our replies!

[HughF]

If the anti freeze valves are opening then the system is being turned off, or they are faulty.

 

Daikin do like to use the backup heater and throttle the heat pump right back at the same time, a completely stupid scheme in my opinion. It sounds like you are trying heat your house on just the backup heater.

[ProDave]

How much OIL did you burn in a year with the old boiler?

[HughF]

9 minutes ago, ProDave said:

How much OIL did you burn in a year with the old boiler?

Yep, very sensible question. We can easily back calculate the electric costs for the year from this.

[Togfather]

I used to spend around £1,400 a year on oil, but I had control over it, being able to set a timer for 4 times a day, and override manually when needed. With the ASHP I have no control. I just have to let it run continuously.

 

How can I tell if a backup heater is being used?

Edited January 19 by Togfather

[ReedRichards]

On 17/01/2024 at 13:07, Togfather said:

I previously had oil fired heating and changed because the installer said an ASHP system would save me money.

I don't think this is true.  I replaced an oil boiler with a heat pump in December 2020  and at that time the running costs were quite close, assuming my heat pump gave me 3 kWh of heat for every 1 kWh of electricity, as an average over the year .  Since then the price of electricity has increased by about 100% and the price of heating oil by 50%.  So unless your old oil boiler was particularly old and inefficient or unless your ASHP achieves a particularly high efficiency I think an oil boiler would be cheaper to run at the moment.  But all that extra insulation should make your home cheaper to heat whatever you use.  And if you could have measured your daily oil usage you would have found you used a lot of oil in cold weather, just as you are using a lot of electricity now.

 

My heat pump has a weather dependent set point.  In my particular case that would make the set point 39 C when the outside temperature is 3 C.  When it gets colder outside the set point get progressively higher.  This keeps me nice and warm inside, about 20 C as a 24 hour average.  But it will cost me more than if I had left the set point at 39 C and shivered through the recent cold spell.     

[PhilT]

9 hours ago, Togfather said:

I used to spend around £1,400 a year on oil

How many litres per year, and was it an old (non condensing) or new (condensing) type?

[ReedRichards]

10 hours ago, Togfather said:

I used to spend around £1,400 a year on oil

 

Over the last 4 years the price of heating oil has varied between about 25p per litre and about 100p per litre.  It would be much better to tell us how many litres of heating oil you used to use each year because the actual price you paid could have varied wildly depending on when you bought.

[Togfather]

Aroound 1800 ltrs. The boiler was a condensing type

Edited January 20 by Togfather

[Togfather]

Today the temperature has risen to around 7 degrees outside. The new setpoint of 43 dgrees is being achieved. The room thermostat is set to 17 degrees now, but only acieving 16 degrees, which is more comfortable than the 13 degrees yesterday.

 

Electricity used in the last 24 hours is down to 67 kWh, which is an improvement.

 

Maybe the setpoint was too low. Should i increase it again to see what happens?

 

Attached are imaghes of the sensor menu.

 

Best wishe.

 

Tog 🙂

[ProDave]

5 minutes ago, Togfather said:

Aroound 1800 ltrs. The boiler was a condensing type

 

Some VERY rough sums.

Assuming you use all of that 1800 litres in winter, or 182 days, that will be 9.8 litres per day

 

Kerosene has about 10kWh of heat per litre, so your roughly 10 litres per day will be producing about 100kWh of heat per day.

 

As a very rough estimate, the coldest day in winter is likely to consume twice the average for the whole winter, so a peak perhaps of 20 litres of Kerosene or 200kWh of heat on the coldest day.

 

So if your heat pump in this cold spell had produced 200kWh to replicate the previous oil heating, it would be likely to have consumed perhaps 66kWh of electricity per day.

 

You say it is costing £29 per day, and with electricity at about 28.5p per kWh that would mean it has consumed about 100kWh in a day.

 

That does suggest it is using the resistance heating for some or all of the heat.

[Beelbeebub]

I notice the first pic says 

 

Inlet backup heater water temp 43C

... 

Refrigerant temp. 37C

 

I may be wrong but this would imply some of your heat is being generated by the backup heater? 

 

 

[HughF]

It’s 100% a settings problem, it’s almost certainly running on the backup heater alone.

[ReedRichards]

I am suspicious of ECO4 installations because you tend to just get what you are given.  In your case you have been given a sophisticated Daiken controller and a very unsophisticated Honeywell room thermostat.  It's likely that your very basic room thermostat overrides your sophisticated Daiken controller, the heat pump is on when the room is below the set temperature and off when the room is at or above the set temperature.  

[sharpener]

As @ReedRichards says the two control modes will be fighting each other. I had not clocked you have the Honeywell thermostat, you should wind this up to 25C so it is always calling for heat and then sort out what the Daikin controls are doing. Ideally it would run 24/7 on Weather Comp with a night setback of 2 deg or so. There must be some way to disable the auxiliary electric heater which is almost certainly what is costing you a fortune.

 

I have also read somewhere that (some) Daikin compressors will not start if their temp is below ?5C so that might be the problem, to overcome this they have a compressor sump heater which may also be wasting a lot of power in the cold weather, or might be faulty so not allowing the compressor to run at all.

 

This is all a bit hearsay I am afraid. I tried to use the Daikin find-an-installer process but it fell down and then they were not interested so I gave up.