@adamk generally not, most of the vibration of the system is taken out by the compressor mounts inside the unit, then the remaining vibration should be taken out by the braided flex hoses left to float freely connected to the ASHP, anything remaining after that should be very low. In some cases it may be that there is 2 elbows opposing or a fitting that can be to close to a bend which may cause slightly higher distortion than desired and this can create noise. If you have vibration noises I would gently lean on the ASHP corner to see if this alters the frequency of the noise and then you can determine if its the HP or the water flow, if its the HP I would 1st make sure the ASHP is dead level, this matters.

@ashp-bobba it’s a Vaillant 7kw aro plus. It’s not dead level as sat on 2x stack of kirb edging on a path that was laid in 1967 at the back of the house.

there is quite a bit of vibration when I touch the primaries at the back of the heat pump, after the flexis it’s maybe half. Odd thing is even in ECO you can hear and feel it running in the utility 4m away from the outside unit.

other installers have had issues with the 7kw and have asked me to keep them updated if I find a cure. Vaillant have been out to some of these and said all is fine.

@ashp-bobba is there a way to run the water pump independently from the compressor so I can try and isolate it?

@adamk interesting, so I have a client that wants us to investigate the same issue on a 7kW Airotherm and has said other companies cannot fix this vibration issue, we have arranged for him to call us back when his system is under full load and the noise comes back in the winter, I am anticipating the call soon. Once we have looked at this and if we manage to find or resolve this I will try to remember to let you know the solution, perhaps you can do the same if you get yours fixed 1st.

I would start by leveling the ASHP system. What is odd is we have just about finished installing a new 5kW airotherm to our new offices and I chose not to install the anti vibration braided hoses, I have had this running for around a week and even without the hoses there is no vibration what so ever. This may be that there is something different with the 7kW model. 

I will investigate.

KR

@adamk I am sure there is in the installer menu, there should be a function to test each component.

Type this into chat GPT and its gives you the pathway to do it.

how to test the pump on a vaillant airotherm

Posted by: @ashp-bobba

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@adamk interesting, so I have a client that wants us to investigate the same issue on a 7kW Airotherm and has said other companies cannot fix this vibration issue, we have arranged for him to call us back when his system is under full load and the noise comes back in the winter, I am anticipating the call soon. Once we have looked at this and if we manage to find or resolve this I will try to remember to let you know the solution, perhaps you can do the same if you get yours fixed 1st.

I would start by leveling the ASHP system. What is odd is we have just about finished installing a new 5kW airotherm to our new offices and I chose not to install the anti vibration braided hoses, I have had this running for around a week and even without the hoses there is no vibration what so ever. This may be that there is something different with the 7kW model. 

I will investigate.

 

KR

@adamk @ashp-bobba

The vast majority of the time my 7kW Vaillant is whisper quiet.  Even standing outside 3m from the front you can either not hear it at all or only barely hear it, and no way can it be heard indoors even though the unit is only 0.5m from a picture window to the main 'living' room.

However it definitely makes a noise when the compressor runs at 100% or indeed above about 80%.  This only occurs only for about 10mins during recovery from defrost and at the very beginning of a DHW cycle in very cold weather.  The unit capacity (once the effect of defrost is taken into account) is pretty well matched to the house loss, but apart from when it is recovering from defrost and even at OAT -5C (against a design temp of -2) it cruises at 70% compressor modulation or less, at which point the noise vanishes. The noise, when it does occur, is definitely airborne and is not transmitted through the pipework.  I have heard others report similar (eg several such reports on openenergymonitor).  For me it is just audible inside at full power, but its quieter and less frequent than my refrigerator, which is in the same room as is the television and HiFi, neither of which it disturbs. 

Although it doesn't disturb me, I was worried about the effect on my neighbours, who objected to my planning application for the heat pump*.  As a courtesy to them I ran it last winter on 'low noise' mode for 8 hours at night, but when I mentioned the heat pump to them 4 months after it was installed (which was mid winter), they told me they didn't even know I had it.  Running on low noise mode slows down recovery from defrost (and thus average output power) quite significantly, and as a result the house cools about a degree overnight when its -2 ~ -5 outside.  However it soon recovers.  I suspect I could eliminate this cooling/further speed up the recovery if I did DHW on immersion rather than the ASHP in the very cold weather.

In summary if what you hear is a noise at 80%-100% compressor modulation only, it is may be this, but it shouldn't be anything like as disturbing as you seem to experience, certainly shouldn't be transmitted through the pipework and unless you have a rare case of an undersized ASHP, shouldn't occur very often or for long periods of time

Hope that helps.

PS  The noise mentioned only occurs when its very cold, <2C or thereabouts.  I have been unable to determine (because I have no monitoring for compressor modulation) whether this is because >80% compressor modulation only occurs at these low temperatures or because there is some temperature dependence in the resonance/vibration effect

PPS You can adjust the limit imposed by the 'low noise' setting and you can also set low noise to apply only at certain times (eg night).  The manual says you can adjust it between 40% and 60%, the actual unit lets you set the limit as high as 70%, which is what I have done.   Ideally I'd set it to 75-80% but that isn't possible, or at least its not possible with the firmware I have.  This limit setting is somewhere in the installer menu on the HP Appliance Interface, the time programming for low noise is on the Sensocomfort.  To get into the installer menu on the HPAI you need the passcode, which defaults to 17 (the default installer passcode on the Sensocomfort is 0).

* despite (or perhaps because of) the fact that they have a swimming pool heat pump that whines audibly all the way through the summer.