Daikin air detected issue on HW cycle

markr · 2025-01-17T17:34:38.269Z

Thanks for your response, in a strange way it’s good to know I am not alone, I have aav’s but only on the space heating side.
The HW return T’s in below my volumemiser so hope air will move to this which has an aav.
I was looking at the Spirovent or getting an aav added to the HW feed pipe but will leave it for a week or two to see how it gos,

Mark

dmajwool · 2025-01-17T17:49:18.257Z

I’m not entirely convinced that AAVs are sensitive enough for this problem. I think they are probably more suited for big gulps of air pockets rather than the micro-bubbles that are interfering here.
That’s why I’m finding value in manually releasing at the points I listed.
Another point to remember is that (in the short term at least) having these air errors is just a measurement problem. The DHW cycle is still heating perfectly satisfactirily. It’s just our statistics in heatpumpmonitor that are taking a substantial hit!
I know that the air does present long-term corrosion and wear issues, but it’s not really a massive heat pump performance problem at this early stage.

markr · 2025-01-17T18:20:19.290Z

Very true.
Would you recommend a Spirovent then ?

dmajwool · 2025-01-17T18:45:33.276Z

As I say, I haven’t noticed the Spirovent doing any improvement. But that’s not to say it is not helping, but it’s not doing enough on its own.
On that basis, I wouldn’t recommend it.

I think the trick is to manoeuvre some heated water into the radiators during a DHW cycle where you will have some manual bleed points that you can use to release it.

On that highest radiator I mentioned, I did also fit an Aladdin Aav, but I don’t think this has been effective either.

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markr · 2025-01-17T19:10:16.206Z

Thanks , HW runs at 3am as cheap electric price, but I have check the rads and 2 off them have new air in them . I will give it a couple of weeks to see how it goes, then change HW schedule if needed and finally look at other methods

Timbones · 2025-01-17T19:22:56.580Z

More advice in these two topics:

Removing Air from Heating Systems
Heat Pump Monitor Kit level 3 - heat meter error due to air

markr · 2025-01-17T20:04:49.836Z

Thank you for this , it is a very good read and helps me understand the issue and some solutions

Mark

Ringi · 2025-01-17T20:56:58.107Z

Shame local hire shops don’t have “vacuum degasser” units.

I expect there will be less air issues if the flow meter is in the return to the heatpump, as the air will desolve more in cooler water.

Spirovent needs to be in a flow of water that is significantly hotter then most of the system water, so may work better if dt is closer to 20c then 5c, but that’s not friendly to heatpumps.

Marko_Cosic · 2025-01-17T23:05:10.845Z

dmajwool:

Another of my theories is that during a DHW cycle only a small portion of the total system volume is circulating, so only that fraction is being subjected to high temperature purging.

This.

You need to to cook off the air in space heating mode by getting it all good and hot

dmajwool · 2025-01-17T23:11:39.069Z

Thanks Marco.
When doing the “cook off” (that’s mentioned in the linked document), how does the released air find its way out of the system? Through the AAVs? It lurks at the top of radiators ready for bleeding later on? via my Spirovent?

Ringi · 2025-01-17T23:38:34.587Z

All the above

Marko_Cosic · 2025-01-18T12:07:49.319Z

dmajwool:

lurks at the top of radiators ready for bleeding later on?

It collects in radiators to be bled out whilst system is red hot

matthewmilne · 2025-01-19T10:47:50.557Z

I have exactly the same issue. Daikin Heat Pump, Daikin preplumbed tank. Have used the document shared on here with no effect on the issue. I have even run as a test the Heat / Radiator side of the system at the same temperature as the hot water cycle and have no air issues reported when I do this, its only when the hot water cycle is run. Can’t make sense of it myself as I thought may be its the higher temperature but this test proved that not correct. So I am at a loss myself and frustrated by the reported ‘Data Errors’. Personally I suspect the heat measuring device is over sensitive / potentially faulty. Given that the Kamstrup model I bought is not available anymore from the store and this model has been commented on across many other forums with similar ‘air’ issues I suspect its the unit which is either faulty or overly sensitive hence it no longer being available now. When I feel like spending on the system again I might swap it out with a sontex to see whether this air issue is actually there or not….

dmajwool · 2025-01-19T11:10:52.543Z

Hi Matthew,

I have an Axioma Qualsonic E4 heat meter and that’s what is showing the air issue here in my Daikin HP and DWH tank.

I suppose another difference with the DHW cycle that may be relevant is that the flow rate is much higher than the CH cycle - and this may be what tips the heat meter into error?

Personally, I think my heat meter is probably working OK and that actually I do have air in my system. My frustration is that I can’t seem to shift it!

I’m going to tolerate it for a couple more weeks until we get some warmer weather and then do another cook-off as @Marko_Cosic suggests.

Marko_Cosic · 2025-01-19T11:19:06.877Z

matthewmilne:

I suspect its the unit which is either faulty or overly sensitive hence it no longer being available now. When I feel like spending on the system again I might swap it out with a sontex to see whether this air issue is actually there or not….

The Kamstrup units are high quality. They’re also high cost - hence the switch to axioms units that are functionally identical but more accessibly priced.

Sontex units will NEVER trigger error codes for air or dirt in the system because they use a different measurement technique. They’re blind to it; so will just report erroneous flow rates instead once it gets bad enough.

You have air in your hot water circuit OR air in the entire system but because the hot water circuit runs hotter or at a higher flow rate it’s only dissolving out of solution in hot water mode.

This will cause corrosion in your heating system over time. Not ideal.

matt-drummer · 2025-01-19T11:32:12.479Z

Do those of you with these issues have inhibitor in your system?

@KnightPhoenix had this problem and inhibitor solved it.

dmajwool · 2025-01-19T11:38:06.158Z

Thinking aloud here : dissolved “air in the system” surely can’t only be in those OEM installations that are exhibiting heat meter errors. Surely it is a widespread effect in wet heating systems.

Perhaps:
a) it is self-healing in typical gas boiler systems because typically temperatures are hot enough to cook it off.
b) it has been fixed in properly commissioned low-temperature installations by the installers running programmes that release the dissolved gas.
c) it remains a problem in low-temperature systems that have never been purged or have been refilled.
Within this last group, its only those systems with sensitive flow meters that will ever be aware of the air problem and the damage that the air is causing to the installation.

Lakee · 2025-01-19T11:40:53.869Z

If you don’t already have one, a short length of pipe and air vent on the flow at the top of the cylinder coil will help remove trapped air. Also running the entire system through a fill & flush pump unit at commissioning will help remove the dissolved air, especially in UFH.

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markr · 2025-01-19T12:11:27.954Z

I hope so , but I have just ordered a checker which arrives on Tuesday

Chris_Hill · 2025-01-19T12:46:01.385Z

you c an slow the pump down in the mmi as a test