@netdonkey Sorry, one more thing, I note you say the system was installed in June 2024? if so, you are still well within your warranty and under HIES all installation companies cannot wash their hands of it for the 2 years you will be under warranty.

Did you do this with the BUS Grant? if so I think HIES would back you up, they will need to attend and fix what ever is causing the low flow. Low flow is not an ASHP issue or maintenance within 6 months.

Posted by: @transparent

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Posted by: @netdonkey

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Bled it and there was a fair bit of air in there before water started to come out but still hasnt made a difference.

Then there's likely to be more air in the pipes somewhere.

The amount of air which came out from that bleed position was "a fair bit", but it's limited by just how much air can be trapped at that location.

Bleed it again 20mins later and you might get more air out.

Equally, you have other air-release valves which are worthwhile looking at.
Even the ones which are meant to be "automatic", can sometimes be less optimal at the job.
Unscrew the plastic cap on the top and press down the brass plunger.
You may get a mixture of air and water before you see just water trickling out.

 

Ive done it 5-6 times and do get a couple of seconds worth of air out.  I did find this on the screwfix forum https://community.screwfix.com/threads/samsung-heat-pump-e911-code-reoccurring.268672/ they mention a pressure relief valve near the ASHP.  Any ideas what that may look like?  Would I even have one?

Nick

@netdonkey yes you would have one in the condenser but its inside the cover and it would look something like that attached link. 

In your picture where I draw the arrows pink and blue for the main ASHP flow and return, do these pipes go across the top and raise up or go straight through the wall behind?  I am just wondering if they took the pipework through the loft there may be some bleed valves at the highest point of the circuit.

https://www.screwfix.com/p/pressure-relief-valve-1-3bar-1-2-x-1-2-/2459V?gclsrc=aw.ds&gad_source=1&gclid=Cj0KCQiAx9q6BhCDARIsACwUxu4dW3541ENXXbIjfn33Hv7Tm7T3idkFeA2WTsIKvrAlzQY_VJS93XMaAvfkEALw_wcB&gclsrc=aw.ds

@ashp-bobba That's what I have hit them with and spent the last hour messaging back and forth.  There are 2 pressure relief valves in the loft.  Opened the one on the return and air came out for about 5-10 seconds.  The valve on the flow released air for about 5 seconds.

After doing that, this one was staring me in the face just above the braided cable to fill the system back up. Opened this up and air came out for about 20 seconds!!  Now the flow is about 9.1lpm which is an improvement and enough to get the radiators going.

@netdonkey excellent, I am glad I was thinking down the right track from the beginning, well done, the system really needs more flow than that, I would suspect there is more air, keep bleding it over the next few days and keep topping the pressure back up to 1.5 bar. form what you described thats a fair bit of air. allowing the system to run for a bit will help collect more air that is traveling around the system to that high point and then you can bleed the rest out.

Please let me know in a few days how you got on.

Will do and thanks for all the help!!

Quick update.

Being going intot he loft and turning the pressure releif valves and do get air coming out which is a good sign.  Can't get it over 9lpm which makes me wonder if the Evosta3 is undersized.

I've asked the installer for the design doc but not sure if they will be forthcoming with it.

Posted by: @netdonkey

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I've asked the installer for the design doc but not sure if they will be forthcoming with it.

We had to fight for ours too, and it's usually a sign that there wasn't one to begin with.

We also ought to consider if the flow is being reduced by sharp elbow joints in the pipework.

There is a considerable loss of pressure if standard  elbows  are used. The best installations will have changes of  direction achieved by the installer making shallow bends with a pipe-bending tool.

If the radius of bend needs to be smaller than can be done by that method, then swept-bends should be used rather than 90-deg elbow joints.

@transparent There are quite a few elbow joints

Have a closer look and see whether these are tight elbows or swept bends.

You might also want to view the comparison between smooth bends and pipe elbows which is well demonstrated in this YouTube video

@netdonkey Hey Net, keep bleeding the air, there can be no air, not even a smidge, any air will reduce the circuit performance, Samsung are sensitive to air locks and flow rates. I still think ask the installers to fix the flow rate and watch how they did it, if they can prove to you it can run between 15-23l/pm then you know the system can be optimal regardless of bends and pipe size, if they cant get the flow then they should review their design.

As you said it used to work fine we need to assume it can run at the req flow rate, then its likely air or something else as the elbow would not have changed.