HeatpumpMonitor.org v2 discussion

Sorry, I’m afraid this is not currently possible. Have you figured out why your system is doing this?

Your outside temperature data doest look right. What’s your emoncms.org username?

not mine, I was just looking around to see cooling data(none)

I think I may have found a bug in the calculations, for my system (Farnborough, Hampshire with Octopus Energy Services) the main page shows as 0 kWh/m².

I believe this is due to us using only the EPC calculations and not the detailed heat loss field.

Do we need to update the other field or is there a way to correct this so the calculation would work off of either set of values (with a preference for the detailed if entered)?

Is there any way to better represent the disinfection cycle on our heat pumps?

My Daikin Altherma 3 uses an immersion heater once a week as part of this cycle.

The electricity consumed by the immersion heater is measured and reported but not the heat produced as it doesn’t go through the heat meter. My immersion heater electrical feed is on a separate meter to the main heat pump as is my back up heater. The back up heater is ok as it is in the heat pump and therefore the heat generated is measured by the heat meter.

I think the energy consumed is worth seeing.

Is there a way to incorporate the heat produced, as the immersion is 100% efficient we know what it is.

would it be feasible to calculate and represent the data relating DHW cycles separately and allow them to be included / excluded from viewing depending on a user filter? This would be so that performance of heating alone can be compared between households that use a lot of hot water and those that don’t.
i.e. show me kwh (whole system) kwh (DHW only) kwh (heating only), COP, etc…
I was comparing my data HeatpumpMonitor.org with another similar
recently and it was proving rather difficult as they have little/no DHW cycles whereas I have one a day at least.

I’ve noticed that my dashboard SCOP has been improving rapidly day by day as we are getting into the heating season - I only sorted my monitoring our properly mid-June, so I have 4 months of data populated with DHW only. which skews it of course!

the criteria for classifying “is it a DHW cycle” could be either: Time of day (if a known schedule), or Flow Temperature significantly exceeds the median , or for systems that have that capability, the value of a binary field that is readable.

There’s some discussion about this over here:

1 Like

I don’t know if anybody else would like this.

I can do the maths more or less in my head but I would quite like to see instant COP at the top of the panel next to 30 minute COP.

It doesn’t mean much but at the moment I am watching what’s going on a lot as I try to work out how to get the best out of my installation.

Maybe other people would hate it?


I’ve made a couple of modifications to the site, trying to take in people’s feedback about it not being clear enough when systems with only a few days are being compared with those with a full year.

HeatpumpMonitor now loads to show only the last 30 days by default and requires a full 30 days of data:

Then it’s easy to either click through the Stats time period: All which shows the list as before or Last 356 days which now only shows systems with a full 365 days of data.

Is this an improvement?

Stats box

I’ve also added a very basic stats box at the bottom that gives the number of systems in the selection alongside COP as calculated by averaging all the system COP values individually vs the COP as calculated by first aggregating total heat and electric for all systems.

An example would be to filter by ‘HG’ for heat geek trained, here will all systems no limit on number of days:

Heat pump type

The heat pump type, ground source or air source is now included as a column to make that clearer.


I like it. Thank you.

1 Like

Thanks @matt-drummer !

Feature request: Please would you consider adding a column for average daily/hourly (when running) kWh consumption?

To save me dividing the total Electricity by the Data length (period). :wink::pray:

Ooo… very nice.

…but how about having it as it’s own row in the table? Either at the top or bottom (or both), or even (dum dum DUM) in the middle? All numeric columns can be averaged (ignoring 0s) with the same rule, so it can show averages for any column that is added, and be sorted into the right place.


Nice tweaks @TrystanLea I like the default 30 day view and the basic stats box at the foot of the page.

1 Like

It would be good if there was a method for messaging the owner of a system.

I have been comparing my system to others (it’s not doing great, a mixture of things I know about and probably not having the right settings yet) and there is another Ecodan 8.5kW (Brighton and Hove, self-install) that is doing much better on a similar sized house with a very slightly lower predicted heat demand.

They have marked it as having ‘Custom controls’ and I’d like to know what they’ve done to get their system operating so well.
It might just be that they have all new radiators properly sized whereas I have a mixture and one still to install. Also my primary pipework needs a sort out. But perhaps I could learn something that would help performance.


Excellent - yes I think it is a very worthwhile improvement.


Yes I think having a row of data for the “average system” would be excellent.
It could then perhaps also be used in comparisons on the graphing pages (might not work in all instances perhaps).

1 Like

The compare feature is a useful way to see how two systems are performing differently:
(be sure to set the dates as the default may not be useful)

We can see that your system (blue) has a much broader spread of COP, and goes to a high flow temperature, and has had to deliver a lot (about 2x) more heat to the building since the start of October.

(If you’d like a deeper analysis of your system’s performance, I’d suggest starting a new topic)



I am the owner of the ‘Brighton & Hove’ ecodan system! Over the past year or so I have made some really significant changes to the original installation to get it working correctly.

The actual COP for the CH is around 5.5. We still have a little air in the system which is causing a drop in the measured efficiency in the DHW cycle as air appears when the flow temp hits 45C.

What have we done to getting the CH working so well?

i) I have upgraded all the pipework from what was originally installed. The primary pipework runs are now in mainly 28mm with a little remaining in 22mm. We have a large Emmetti manifold that distributes water directly to each radiator uisng 16mm MLCP pipe. There are no TRVs.

ii) there is a single large Grundfos MAGNA pump. Our flow rate is typically 1440l/h. That is 24 l/min. There is a section of 22mm pipe remaining and I expect we will see it increase further once that is shorted and replaced in 28mm.

iii) we only ever turn off two radiators in the loft extension (office) at the weekend. We have no other radiator controls. Each radiator gets a measured 4l/min from the manifold.

iv) the heating controls are a combination of loxone/knx. In reality is is very simple config. We have a precise digital thermometer in each room. When any room ‘calls for heat’ the system comes on and heats every room in the house. The system has a minium run time of 1 hour. It currently runs at a manually set 32C.

v) as the temperature drops as it cools the system will remain running all day. At that point we will increase the flow temp. I am hopeful we will not need to push it beyond 40C. This is estimated and hopeful, rather than being scientifically calcuated.

vi) radiators are typically long K3 ones. It seems to be that there is only one room (the kitchen) that is causing the heat to come one. I think that this due to poor insulation/drafts and an undersized aluminium radiator that was originally used with a gas boiler. I am considering replacing the rad with a floor standing 1600x300 K3.

I have found the width of a radiator to be the most critical factor, and the height is not needed. A thermal camera image of our 900x900 radiator shows the bottom half doing very little.

I convinced that TRVs are bad for a ASHP installation. They throttle the flow by partially closing when a room is at temperature. ASHP is much more suitable to a ON/OFF arrangement. And then using the precence of an ON to start up the system; then we give every room heat while the system is running.

Currently the system comes on when a single room wants heat. I could change it so that it requires two rooms demand heat before the system starts up.

Let me know if you need more, or pictures.

Incidentally we use every rooom in the house each day (other than the office being unused at weekends), and the house is always occupied.



Hi George, thanks for identifying yourself and giving a really good description of your system.
You’ve done a great job of getting the unit to run really well.

I was interested to hear what the custom controls were to see if this was why it was running so well but it sounds like it is mostly ‘just’ a really well set up system and the main difference between our 2 systems is the inadequate output of my radiators and pipe diameters.

I’ve been finding that running on pure weather comp I’ve been getting much worse COP than Auto Adapt which shouldn’t make sense however without enough output the system cycles loads as the flow creeps up. Whereas AA compensates for this by allowing the flow to drop more between cycles meaning heating the water in the system can match the HP output and then it takes the flow temp much higher to maintain a larger DT between the radiators and room so again providing a better sink for the output. All while checking the effect on room temperature isn’t too high.
Basically it is good at compensating a bit for the inadequacies of the system. I was thinking when we get the big hall radiator added I might get as much primary pipework increased to 28mm and I think you have confirmed this would be worthwhile.

One metric i’m becoming more interesting in is total system volume.

Selfishly i’m trying to work out why my 5kW Arotherm cycles way more than others on the list.

I’m around 90L total system volume including pipework (10 rads, no buffer/volumiser).

So I think it would be useful to collect that data? :grinning: