UPDATE.

theyve been and sorted the flexis today by moving them so they are vertical, about the only way they could do it without moving the heat pump, so that’s sorted. Also said they will send the sparks to replace the rcd/mcb’s. So hopefully near the end of the pain, well at least until winter when I find out which rads I need to change😀.

Posted by: @adamk

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UPDATE.

theyve been and sorted the flexis today by moving them so they are vertical, about the only way they could do it without moving the heat pump, so that’s sorted. Also said they will send the sparks to replace the rcd/mcb’s. So hopefully near the end of the pain, well at least until winter when I find out which rads I need to change😀.

Great news

I edited my previous post (probably after you read it) as the Vaillant manual, at least to my reading and in the version I have, actually permits the arrangement you have.  However if they are going to sort it anyway that resolves the matter.

I’m back,

well Vaillant called me a week ago at which point I explained I was still waiting for the electrical works to be rectified. They said they would email them. A week later and just over 4 weeks since they visited last no contact from them. I’ve since commented on a vid about a heat pump install stating the heat geek logo doesn’t guarantee a good install. Interestingly heat geek replied asking if I meant they weren’t heat geek. I stated no they are. Then silence. I’ve emailed heat geek to request I talk to someone who replied cause they are saying even though I didn’t go through heat geek they expect there installers to do stuff properly.

@adamk, interesting point. I’ve not focused much on Heat Geek installations because, compared to other schemes and organisations, we haven’t seen real horror stories. Sure, I’ve had a few emails and DMs about issues, but nothing catastrophic.

That said, as the Heat Geek cohort grows, I’ve noticed a problem with their guarantees. It all comes down to how you hire your installer. If you go through their platform, you get the guarantee. If you hire direct, you don’t, you’re on your own with no Heat Geek backing. 

I published an article on this last night to make things clearer:

https://renewableheatinghub.co.uk/what-is-the-heat-geek-guarantee/

Had a new Vaillant 7kw installed with new 28mm runs for primaries and flow and return. I’ve got a variable pitch humming sound that resonates through the house depending on how hard the heat pump is running. Admittedly this is just a test run I’m doing tonight but it worries me as i can hear it above the TV.

one thing my plumber who ran the 28mm’s did do was clip them against the wooden ceiling trusses. Could this be transferring noise into the house? With the old boiler setup and pump you could only really hear the pump where the pipes were exposed in the kitchen just below the pump in the cupboard above.

One other thing, I haven’t balanced the rads yet so currently just have the try end wide open.

Posted by: @adamk

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Had a new Vaillant 7kw installed with new 28mm runs for primaries and flow and return. I’ve got a variable pitch humming sound that resonates through the house depending on how hard the heat pump is running. Admittedly this is just a test run I’m doing tonight but it worries me as i can hear it above the TV.

one thing my plumber who ran the 28mm’s did do was clip them against the wooden ceiling trusses. Could this be transferring noise into the house? With the old boiler setup and pump you could only really hear the pump where the pipes were exposed in the kitchen just below the pump in the cupboard above.

Cant hear a thing with my 7kW Vaillant* so something is wrong.  Can you tell whether its the water pump, the compressor or (unlikely) the fan.

Its possible that the clipped primaries are transferring noise.  I do have some clipped 28mm primaries also but only in the utility room and garage (where they split into 2*22mm - the original pipework).  This could depend on exactly how they are clipped 

I presume that installer has fitted flexible pipework for the final metre or so to the ASHP and that the ASHP is on proper rubber feet.?  

* exception - during recovery from defrost when compressor is at 100% I can just hear the compressor indoors.  The unit sits <1m from the room in which I hear it adjacent to a window and the noise transfer is airborne.

Roof trusses and dry lined ceilings are a massive sounding board. This is a very common issue with sparks who screw bathroom extract fans direct to roof trusses - they sound like a helicopter is landing on your roof! Use rubber lined vibration resistant pipe clips and that will help hugely. External circulating pumps are usually supported by the copper piping, and vibration gets transferred into the piping and from there into the fabric of the house. Also, with a new system, you may have a higher flow in the primary pipework than the system flow requirement, and that could be generating noise due to high pipework velocities.

@adamk If you are willing to investigate you can take a large flat screwdriver, place it on the area near the noise and measure by simply gauging the volume of noise you hear through the screwdriver, you hold the tip firmly on what you suspect is amplifying the sound and then place your ear actually touching the handle which hones the vibration through to your ear, this is a very old engine technique used in the good old days to check tappings inside a rocker case and works well on resinating pipes to locate the offending clip or touching pipe to sound boarding. 

Tips that may and indeed may not help:

There may be a chance that where the plumber has installed a bend and the bend is tight the small amount of expansion in the pipe warming up could have caused the pipe to be tight in a clip, when clips are in a straight line they can allow the pipe to expand along that line reducing pressure against a sound amplifier (sounding board).

Check if there is braided flex pipes on the ASHP to the 1st connecting copper pipe, these do actually need to be slightly offset to help them reduce noise, dead straight tightly connected flexes seem to be less effective, perhaps as the vibration is forwards and backwards rather than up and down, I cant explain this but experiments we have done seems to show offsetting slightly helps.

Assuming this is a buffer free system without a secondary pump, you should have no need to check the pump speeds and velocities and assuming the installation is of top quality its unlikely any of the pipes are making these noises where they are a bit on the smaller side.

Good luck in tracking down the noise and please let me know once you find it as we have a Vaillant Airo 7kW to investigate in October with exactly the same issues, the client just asked us to wait until it was cold as its much noisier in the winter, but exactly the same issue so I am wondering if its a Vaillant thing maybe? 

KR

Sorry, I should also add these checks 

The ASHP must be dead level no exceptions, this helps the mounts on the compressor evenly dissipate the vibration form the compressor before it exits the unit.

The Unit must be on anti-vibration mounts of some kind to cancel out any access vibration and then the flex line connected. 

All of the above help remove any unwanted vibration.

Ok took some pics. It’s seems level one end front to back, but everywhere else it’s out, like the casing is twisted. Where is the best place to measure? Also the flexis are in the section in the photo where the 3 wall clip mounts are just below the valves.

Levels don't look terrible and it appears they cast concrete bases so i would have through these would be level?   

so the wall clips are holding the flex to the wall?