Hi Jonathan @squarepeg77 and other Daikiners using ESPAltherma!
My new mate Dan the Daikin engineer came by yesterday, and looked everything over. He was very pleased with the way I’m running it, and when I prompted him to look at the tape heaters, they were in fact activated, in contradiction to the service manual activation conditions. He called a product manager in Bristol, and there is apparently a service bulletin on exactly this situation i.e. for users closely monitoring HP performance with 3rd party equipment, the link between 5 & 7 on block X7M can be removed, which disables the tape heaters in “normal” conditions! Dan reckoned the standard “link present” setting is a very cautious setting to prevent ice forming in the unit in colder weather, and since most people don’t track the R1T/R2T/R4T explicitly, that’s how they leave it.
So my sensors are now ±0.1C, which is a great result. I’ve removed the offset I previously applied, and will edit my “calibration” post.
He was utterly fascinated by the ESPAltherma, which I’d left connected, because it’s extremely cheap and very effective. When I said the M5C cost < £20, he was stunned, expecting it to cost £00s! I showed him EmonCMS etc., and sent him some links about it all. He felt that all heat pumps should come with that level of monitoring as an option, if not even as standard, because it’s hard (impossible?) to sort them without it. Daikin are apparently looking at such an option, but it’ll probably be years coming. Clearly there’s a market for someone to install ESPAltherma + Emoncms.org access for users!
Of course, there remains the question of how the HP functions correctly when its sensors are delivering misinformation i.e. Return R4T is at least +0.5C, making getting an accurate dT hard. I guess it’s only 10% on an dT 5C , which is noise compared with all the other shenanigans.
Thanks to @squarepeg77 !! I will now be considering my downsizing options - it’s still clanging away at 900W, which Dan agreed was fairly hefty, if you could halve it.
Thanks to the efforts of @squarepeg77 and Dan from Daikin (thanks!), the cause of the R1T/R2T/R4T thermistor value differences has been traced to the tape heaters around the plate heat exchanger being activated as part of what seems to be a “belt and braces” anti-freezing policy by Daikin. Your friendly engineer can remove said link (5-7 on X7M) which is described in a Daikin technical bulletin for exactly this situation i.e. using 3rd party monitoring which relies on these sensors, which in my case got them to within 0.1C of each other.
So now I don’t need the offset! And I’m saving 66W while the circulation pump is running. Hurrah.
Hi @John, I’m pleased you got the tape heaters fixed and got some good answers from your engineer.
My contact at Daikin didn’t think the (IMO misleading) temperatures would affect heat pump performance as he said there was some calibration done internally.
I beg to disagree: I think my system is much better since the change. It’s hard to prove though as the weather conditions have such a big impact on performance and I only started using ESPAltherma at the end of December.
However I’m pretty adamant that my system wouldn’t reliably deliver the requested flow temperature and delta T before the tape heater fix, and now it does.
I got no affirmative reply to the part of my email that suggested they needed to sort this out as it was impeding performance. So I am very gratified to learn that a service bulletin is in effect.
Heck, saving 66W at minimum output is a pretty significant ~7% electricity saving! Imagine that across the installed user base…
No, sorry, it took him a couple of goes to get the guy, it was a short conversation and I don’t know if anyone in it knew the number, because I didn’t ask.
And that is a good question. You could look at the service manual for the 04-08 models to see if their tape heaters are the same config at least.
Very interesting thread! I’m considering having an EDLA04EV installed.
Reading this thread, all I’d need to get accurate monitoring up and running is:
External electricity monitoring on both the pump and water cylinder circuits. Something like a Shelly Pro EM would be enough for this, correct?
An ESP32. I assume a M5StickC PLUS2 would work?
4 Dupont wires from ESP32 to the X10A connector
I already have Home Assistant up and running along with an MQTT broker.
Am I missing anything?
Do we know how the accuracy compares to setups with a dedicated heat meter? (EDIT: Ignore this question. I just went back and re-read the thread this morning and this is what’s being discussed with all the temp comparisons. Apologies!)
The above would give you a good idea of what is going on but these devices and the meters used on the Daikin heat pump are not mid certified, therefore there is no guarantee of accuracy.
For a truly accurate solution then the level 3 heat pump monitor kit is best (a bit more expensive but very accurate and simple to set up).
I guess it depends what you want to do. For me, the Daikin data in conjunction with a cheap Tuya CT consumption meter tells me enough to get the HP running better. That’s cost me maybe £50. I have a EDLA09 9kW HP, so I’d need the middle of the range OEM-style heat meter, and I’d have to pay to fit it, so it’s going to be £800+.
I used to use HA for monitoring, but its data analysis is pants, and it throws data away after 10 days unless you can be bothered to fiddle with it, so I set up EmonCMS and am much happier. It would be possible to go direct to emoncms.org, but the ESPAltherma software only does MQTT, rather than HTTP GET/POST as per the original EmonCMS input requirement. I am currently looking at adding that as a feature, so users wouldn’t need a local EmonCMS, but don’t hold your breath!
This is my dilemma. I’m looking to have a heat pump installed by Octopus and they are refusing to install a level 3 monitor kit at the same time so I would have to retrofit it later on.
I’m considering whether to go with ESPAltherma instead as the setup looks fairly straightforward. I assume labour for retrofit would be at least a few hundred pounds (on top of the ~£500 cost for the kit).
With your CT consumption meter, do you monitor both the HP and hot water cylinder consumption?
In terms of stats from the cylinder, is there a separate kit for monitoring it? I’m thinking the main interesting bits would be consumption and current DWH temperature.
At the moment the ESPAltherma repo doesn’t support the M5Stick C PLUS 2, there have been a couple of posts in Issues and Discussions section of the GitHub repo about this.
You’re going to want ESPAltherma for sure, so you can differentiate DHW from space heating in emoncms. One of the other main benefits is reading the intended LWT of the system, precise to 0.1°C, which is really helpful for understanding what your system is doing.
I am fortunate enough that Octopus Energy installed full OEM monitoring (something I neither asked nor paid for (this was in March last year, as you’ve found, they don’t “offer” this now))… If I was having to pay out of my own pocket, I reckon ESPAltherma probably gives you 95% confidence of knowing exactly what is going on with your heat pump and I wouldn’t have put OEM in myself. Maybe get ESPAltherma first and if you really want that 100% confidence you could retrofit OEM.
On heatpumpmonitor.org you can look at the Port Talbot Daikin for an example of the inaccuracies of just ESPAltherma data. As the flow and return values are not calibrated and there’s a difference between the two values on this system, as a result even when the heat pump is not running it is showing heat output. This means the true COP of the system is inflated considerably.
So, that system is not ideal for comparing on a “leaderboard” like heatpumpmonitor (and is why a recent update to the site “greyed out” these non-MID systems). But for just understanding your own system performance and tuning your own system settings, I think those inaccuracies of data are less importart and can be ssentially disgarded as the error in the data is consistent for your own system.
The goal of the monitoring is to get it running well and save you money, so why spend £800 when £10 will do… A basic electricity CT meter won’t add much to that to give you better electricity input (esp tends to just report on compressor current and misses fans, pump, idle electronics etc).
Espaltherma will let you see all the behaviour and cycling and modulation you need to get it running well. It won’t be a truly reliable comparison to compare to others on the heatpumpmonitor site but then everyone’s house and situation is very different anyway.
I’m sure I’ve seen someone state a comparison between MID values and espaltherma somewhere and it was fairly close.
The DHW booster is normally just 13A resistive heater, so estimating that from the BSH on time is fairly straightforward, or you can adjust for the voltage if you have that value available, and measure resistance if you really want?
You’ve both made a very good job at putting it in perspective, thank you
I think I’ll do exactly that - go with ESPAltherma for now and see how I get on, although I’m sure I’ll curse myself if I end up going with the OEM kit later on as I assume the retrofit cost is significantly higher than having it installed with the pump.
In terms of cables between the pump and the ESP, I saw some people said they had used an Ethernet cable. Is this as simple as it sounds? Get an Ethernet cable, crimp the correct connectors on four of the wires (female dupont HP side, male ESP side if using M5StickC).
Is there a max length? I’d be tempted to ask them if they’d at least run an extra wire up to the airing cupboard as they will do for power to the cylinder anyway, unless that exceeds max lengths on the cabling. That way the ESP could live indoors. Otherwise I’ll just stick it in the outside consumer unit.
Would there be any value in running a separate Ethernet for the heat pump at the same time? I read something about a Daikin LAN module but I don’t really know the benefit of it.
I used some cat6 cable I had, it works.
Max length - it’s a serial cable, so maybe 10m to be safe?
M5Stick in case works ok if your WiFi signal is ok, otherwise in the cupboard might be better, because case is effectively a Faraday cage!
Daikin MMI only takes a WiFi adapter, if it’s Octopus they put one in anyway, there’s no Ethernet connection. It’s helpful because you can control your HP remotely using the Onecta app, via the Daikin cloud.
Had my 8kW Daikin installed on Thursday and have now got this running and logging. The ESPAltherma code has been updated for the M5StickC Plus 2. Got mine from RS as they seem out of stock everywhere else. I’ve not got a separate power meter so taking the data straight from the Daikin unit.
One question I have is why are there 2 fields for the current used (INV Primary Current and INV Secondary Current). It looks like everyone is using the Primary one for COP calculations. Why not the secondary one? Anyone know the difference?
I don’t recall if anyone here is using the ESPAltherma returned values for electricity power measurement. I think they are considered not very accurate, so most people are using some external measurement: a CT clamp hooked up to another device (an Eddi in my case) or another electricity meter like a Shelly
Which cable did you use to get the length? I am confused which wires and plugs I need to buy. I am hoping to use a M5StickCPlus2 when they are back in stock.
The EH connectors are stubby and if you try to crimp these remember you must leave the end exposed when crimping so as not to crush the connector (seen it a number of times).
Yeah the StickC uses 4 pins, but they’re not contiguous in a block of 8. I used a 2x5 & a 2x3 block connectors taped together with pins inserted to make it stable, I didn’t have an 8 way block.
, which is noise compared with all the other shenanigans.
