Vaillants response is typical of what ive heard from other suffering from this issue. im not sure what they want to achieve from this as bad end user experience can bomb sales once word gets around. its not like were asking for the whole unit to be replaced we just want a fix that doesnt look like a bodge. if that involves a different compressor surely they can change it out?
Iām going to throw my hat into the ring here too. Our 7kW Vaillant puts a strong, low-fequency vibration into our house which is audible in every room. I find it very annoying. My wife hasnāt mentioned it yet, but as soon as she starts complaining, things are going to get an awful lot more serious!
As with others, our vibration changes in pitch and intensity based on what the heat pump is doing. It seems at its worst during defrost cycles, but itās pretty strong on regular heating activity during this present cold snap.
Hereās a Spectroid scan from our master bedroom during a heating run. At that time it was consuming 1700W of power and producing 5800W of heat with an outside temperature of -0.6C.
Is there anything that can be done? Our installation is about a year old, and the vibration has been with us since the beginning. It was done by our local Heat Geek; a good guy.
Can you share some info, and possibly photos, of your primary pipework runs from the outdoor unit to your cylinder/indoor location?
The heat pump is by our back door. The primary pipework runs up the wall, enters under the floor of the landing, runs down the landing into our airing cupboard in the centre of the house. The external pipework is insulated with Primary Pro and clamped using their rubber lined brackets. It all looks fine. If you ask me, the vibration is coming from the radiators but low frequency sounds are hard for people to locate. Here are some photosā¦
What do you think? I can feel vibration in the external primary pipework and at the back of the unit.
Could you capture some video/audio of it on the outside and in too?
If you put a finger on the plate highlighted, can you feel it vibrating, and does it chnage when you are pressing it?
Interesting. Iām now getting an almost rumbling oscillating noise on top of the hum.
Very much like a low tumble dryer noise.
Would you mind sharing where the strainers are in the system?
that insulation is proper awful on what im guessing is the flexi sections, though they didnt leave themselves enough room to be honest. could do with the gaps where the elbows are covering.
it depends to be honest. ive got a intaKlean HP Heat Pump Magnetic Filter in my tank cupboard which has one in it, and another in the inta isolator valve outside. you will get an idea if they are blocked by how much the system pressure according the the Vaillant app swings by when the circulation pump if on or off. when mine were blocked it dropped from 1.5 bar to 0.75 bar each time the pump was on. if your running 24/7 like me you might need to stop the heating to see the resting pressure or look at the gauge on the fill loop and compare to the app with the pump running. you will get some drop but not a massive amount.
the other indicator is when the compressor is not running but the circulation pump is, have a look at the power consumption, if its like 58w then the pump is maxed trying to achieve the flow rate.
my 7kw with clean strainers and running the pump test to 100% gives me 1500+ l/h.
Hereās a link to a video file.. PXL_20251121_153530609.TS.mp4
Nothing changes when I press on that little panel.
The strainers seem to be part of the isolation valves right next to the heat pump (you can see the valves on my original photos.) Can I look at the strainers myself? OEM reports no drop in flow rate over the lifetime of the installation. The system is due its annual service, and my Heat Geek will be visiting in a couple of weeks to do that.
Explore if coming from the pump or from the compressor: If the tone changes or goes away with different flow rates or with different levels of compressor modulation. When the sound deadening panels are off, the sound will be a lot noisier and may be able to further identify where is coming from.
Have you checked the flow rate in the wall unit is the required litres per hour and pump speed not at 100%, such as from over throttling at radiators from balancing?
The unit looks very close to the wall, I checked the specs and its 200-250mm. Mine is 300mm away and the flex hoses are not so sharply bent, which may not be helping with the pressure of the bend on the unit and vibration coming through.
Someone just posted on Facebook that Vaillant have a sort of fudge to fix the noisy compressor issue.
Adam I had an interesting conversation with Vaillant technical support. Officially there is no known issue with the 7-kW Vaillant. Unofficially thereās a known issue that some 7-kW compressors are noisy. The 7-kW compressor is not limited in any way (whatever that means) and if you can highlight the specific condition that it makes excess noise mor vibrations their technicians could put a limit on the compressor in that specific condition
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Interestingā¦ any more detail? I wonder what theyāre referring to when they mention ālimitingāā¦
Just a guess but they could just block certain compressor frequencies close to the problematic mechanical resonance.
This is what I was thinking, but surely this would involve a big intervention in the control logic and firmware, and famously the firmware isnāt field-upgradableā¦
During some of my resonance periods, Iām capturing screens and data, as i dont have the hardware for some of the hardware for some of the values.
Is the compressor speed available in any of the controls?
Looking at Mickās ever excellent pages and the widget for performnce, starts to gives a table to work with at outside temps, current power & Flow temp, to cross ref into compressor speeds to allow some record of the start of the noise.
Also capturing video/audio from the same location for consistency.
Will also add spectroid captures.
I get frequency changes in the noise levels as the compressor when outside temps change and the pump increases to meet the flow temp delta.
This was all captured last night at 19:09
Metadata/config below -
- 7kW Arotherm+
- 3 bed bungalow, well insulated. All rads & pipes replaced for flow rate & temp design.
- Central Scotland.
- Single open zone utilising UFH Manifold, but no actual UFH.
- Room Temp Mod - Active
- Sensocomfort in Hallway (not a cold zone due to doors)
- Desired- 02:30 to 20:30 - 20.5Ā°
- Setback ā 18.5Ā°
- Heat Curve - 0.65
- Min flow temp - 15Ā°
- OT switchoff - 16Ā°
- DHW Scheduled cycle - 14:00 to 15:30 to 51Ā°.
- Legionella 1 per wk @ 15:30
- HA for monitoring and automation
Iām getting really sick of this constant hum when the heat pump is working hard. Has anyone found a solution? Will Vaillant come out and sort it?!
I have been paying attention when my interior noise is at its worst. Around 50 - 60 percent compressor is the loudest. Ironically this is where noise reduction mode sits at if needing the heat. I have it on that during the night for the neighbours sake. Outside the house it is noisiest at 100 percent compressor or defrosting which would be expected.
Currently Iām replacing the plastic pipe clips under my floor on the primary flow and return with rubber sleeved ones. Not sure it will make much difference but I need to try something. Seems to be the return that has the vibration.