All systems should have a strainer. Sometimes mag filters have an integrated strainer, but most mag filters don’t so you would need to check e.g I’ve got the intaKlean HP mag filter which does have a built-in strainer:
The strainer can be integrated into an isolator valve e.g
Or they can be standalone e.g
Hi Mick, I have a Mixergy cylinder too and a monitored ASHP, but Im not using the ASHP to heat it currently just an immersion via an Eddi. Even though the plate heat exchanger may not be as efficient at transferring heat as a coil, I think that has to be weighed against the fact that because of the Mixergy’s design you dont need to heat it fully to get an equivalent amount of hot water. I can have a good hot shower when its only 10% full, which isnt something I could manage on my last cylinder. Just a thought.
Not quite my best COP (I got 4.36 was when it was 23C outside), but i’ve got best % carnot here on this run today. 23C run was 42.6%
This is another LONG run, proving that the colder / emptier the tank, the better the performance is.
205L of my 250L Mixergy to 51C target temp at 18C outside.
Vaillant pump speed: Auto
Hot water mode: Balanced (which to 45C it runs full compressor, 50% for 45C and above)
Sorry to crash the thread, but is it possible to run an Arotherm+ with Mixergy on the indirect coil without the Mixergy HP interface electricals (‘resistor switch’)? AFAIK the Vaillant expects a resistive signal rather than on/off DHW call (24V contacts on S40 pins). I can’t quite stretch to the full Mixergy HP interface kit at the moment so I wanted to run on indirect coil for a while (albeit inefficient, but still better than immersion).
(I should add, I want all the DHW control to be via Mixergy with Vaillant as the slave)
Thanks
Hi @Zarch,
Only just joined, and am extracting data via ESPAltherma rather than Heat Meter, but I have an Octopus Energy Service installed Daikin EDLA11DA3V3 11kW heat pump, that they reluctantly hooked up to the 210L Mixergy cylinder I got in 2018.
Mixergy provided an upgraded and replacement Plate Heat Exchanger, new pump and also a Heat Pump interface for Octopus to fit (I became a middle man on this).
Mixergy app set to 65C, and set to 70% on overnight charge (generaly empty/full cold) which equates to ~50C tank temp, and then just before Intelligent Octopus off-peak time comes to an end, I push the whole tank temp up to 65C daily via the controlled top immersion to gain additional hot water volume (when mixed down to 46C on the TMV sat on the output of the cylinder) as our cylinder could do with being 250-300L really based on usage an really only wanting to recharge off-peak daily (understanding CoP will be lower due to outside temps)
70% (right column) equates to approx 50C tank temp:
My system is located here:
https://emoncms.org/app/view?name=9ChurchStreet&readkey=53fbf32311dcafcbf15209adc8e10c7f
Thanks @Stephen_Crown
I will keep an eye on your data.
Even with just a few days data it looks like you’re getting better COP out of your setup than mine at similar outside temps and similar target water temps.
I’m wondering whether it’s just my small 5kW heat pump? Perhaps their one size fits all plate just doesn’t like my system?
Indeed, lots of variables including I’m not not using a “proper” heat meter, but I’m hoping over time others with the same unit like Matt on the other thread can provide some data to show how close proper vs system data is.
This is the Sika flow meter I believe? In the Daikin unit that is supplying the flow data to EspAltherma
This is the instruction booklet that came with the free of charge upgraded (and a fair bit bigger) PHE kit they sent me in summer 2022:
Is this kit the same as yours?
Same instructions here
Do you have a photo of the ‘fair bit bigger PHE’?
I’m intrigued now!! 
Old and never used PHE as delivered in 2018: (used as a transition from gas similar to you, but had always planned to move to a heat pump from around 2016)
Just as it was being installed (replaced with the new kit including new pump which seems to match as described in the pdf I uploaded in the previous message) by Octopus:
It was a bit of a nightmare actually as Octopus had no idea how to plumb it up or wire it up.
They didn’t pipe properly the small other pump that takes water from bottom and sprays onto top of tank, so that didn’t work and resulted in the first night top Mixergy inmersion only run (only 1 day heat pump work to be fair) hitting 80C at top of the tank and the pressure relief valve leaking water into the tundish….which then needed replacing with Mixergy parts (Octopus fitted as they messed up).
What made it worse it that my early mixergy tank has a bottom failsafe no -smart immersion that Octopus promptly decided to make their own, disconnect from my real dumb timer (failsafe) and connect into the Daikin controls….didnt work properly and can on at random times.
I told them the Mixergy controller has a legionnaires cycle using top immersion that can’t be disabled, and so come back and give me my failsafe dumb immersion back. They did do this.
It’s all working fine now though to be fair.
Thank you.
Does that new one have a label on it at all?
I don’t have a photo sorry! Not without peeling the insulation off.
I really do like the Mixergy controller and app though.
Came from a combi where no running out of hot water.
Can’t imagine having a tank an not knowing what state it is in!
I would have another, even though I see on other sites etc. it is frowned upon.
Unless you’ve had one, I’m not sure people get that Sufficiency beats Efficiency.
What I mean by that is if I want say 8% to have a shower (and is showing 1% left), it is quicker and uses less energy to heat the very top up to 8% vs having to heat the whole tank (which then also takes out your heating as well)
The other downside with reheating the whole tank (when only a small amount needed) which you’ve mentioned elsewhere, is that you would then have a tank say 80-90% charged with warm water, absolutely killing efficiency on the next overnight charge.
I quickly worked out (without much in the way of monitoring!) a quick Mixergy style top up for a small ish amount (say under 20%) was better than reheat whole tank.
I’m a bit late to this one, but the workaround I have is set the SoC to 70% to get an overnight recharge temp around 50C when tank settings are are set 65C (which I use every night to bring the whole tank up to 65C as the 210L tank is too small for our usage)
If I need a whole tank recharge in the winter evenings, then 55% SoC equates to around 43C, and 45% equates to around 38C.
Interesting, thanks Stephen.
I just use the Home Assistant integration now.
You can poke whatever target temp you want at the tank using that, ie 47C
I do prefer to do full tank runs with the ASHP.
Part loaded seemed fine on immersion only.
But part loaded with the ASHP seemed to leave me with weird water temps, which you’re probably taking advantage of here.
If the tank is target 51C, I want 100% at 51C. 
This is interesting, and made me look closely at flow rates for my setup….and compare to yours.
I saw yours was around 10L/m -ish and mine was 24L/m - yet the documentation for the Daikin 9-16kW Altherma 3M Monoblock states 28L/m as minimum flow rate for DHW recharge.
I also seemed to remember seeing ~30L/m or just over when I first got the unit and was glued to the Daikin controller (given flow rate etc. was only available there)
Just kicked off an evening DHW recharge and the pump is now holding some power back at a value of “18”, which is equates to 28.2L/m - good I guess as it normally sat at “4” (100=off , 0=max speed - however have not seen a value lower than 4)
Power mismatch? Your Mixergy pump setting might be worth testing on “2” rather than “3” for example- mine is set to “3” for reference.
More detail on my findings and partial blocked filter on the flow rather than return here:
Despite numerous questions to both Mixergy and even Lowara no one can tell me the flow rate of the pump on settings I, II and III.
I’ve even contemplated fitting a flow setter/reader on that side of the plate.
So I can then properly match the flow rates on both sides of the plate.
Mixergy says “it doesn’t matter”, but surely it does?
Mixy say just stick it on setting III.
They’re heating the tank as a “fully stirred vessel”
Excessive flow, other than burning pump energy, is not a problem and will improve the performance of the heat pump in the same manner as an excessively large internal coil in a cylinder would.
Thanks @marko
But what about within the plate itself?
I was under the impression matching flow rates across both sides was recommended? To avoid distortion and give better heat transfer?
So trying to match the heat pump flow rate with that on the cylinder side?
Overflow on the cylinder side won’t reduce heat transfer effectiveness. It’ll just waste pump electricity,
What else should we be doing on Saturday night than try and work out why your DHW runs are still no good compared to others. 
So from those Vaillant technical charts I created these tables in excel that show expected COP at various flow temps as well as different outside temps. For both Eco (50 rps) and Normal (110 rps) for both the 5kW and 7kW Arotherm models.
I ‘filled in the gaps’ between the COP provided with a simple bit of spreadsheet jiggery pokery.
Using the new “instantaneous COP” feature i’m able to see where things seem to be going wrong.
If we look at Adam Heat Geek cylinder attached to his 7kW Arotherm you can see this steady decline of the COP inline with the increasing flow temp. See my purple addition there.
You can a very similar looking graph on @glyn.hudson parents 5kW Arotherm
Compare this to my Mixergy then.
I constantly see this terrible start. I’m getting COP 2 to 3 when the heating 30C water.
Glyn and Adam are getting COP 5 at this stage.
This must be where things are going wrong and where i’m missing out on early high COP?
When the flow gets to 50C things are on track and i’m getting around the COP that should be achievable.
So now I can see what’s going wrong… how to fix it!!! 
Note: Neither Adam or Glyn hit the exact COP output, there are always a little down on “expected output”, but assume there’s something about DHW that stops this.
UPDATE1: Interestingly, here’s an Eco mode run from August I did. It looks better. It’s still 1.0 COP lower where it should be for 35 flow, but much better than in the 2.0 range.
Is “Normal” mode just trying to throw too much heat into the situation from the off?
