Wall brackets and drip trays for wall mounting of ASHPs are readily available.
So that shouldn't be a problem.

The issue is accessibility.
If there's a flat roof beneath, then access is easy.

Noise and vibration transference concerned me greatly - though I could see that even if vibration problems * could be negated (and I doubt how effective this might be) the noise being just outside the bedroom window would not be favoured! Access for servicing would have to have been via a ladder / tower so that didn’t appeal much either! Perhaps by the mid-2030’s, there will be ‘silent’ and much smaller / neater ASHP’s that could be installed almost anywhere!!! ;-)))

* I did investigate various anti-vibration mounts etc. in the early days of my research; the general feeling seem to be that at best, they would reduce vibration transference but could not be expected to eliminate it. I am also aware of the existence of wall mounting kits so, really noise and vibration were the real no-no’s for me. Regards, Toodles. 

And going back to the very informative article ‘

‘10 Things To Consider When Choosing Pipe Insulation Thickness ’

I would class the ‘heat loss’ in the airing cupboard as “Always Useful” and am happy to leave the current pipe-work ‘as is’. Regards, Toodles.

Bringing this right back on topic (noise),
can I point out that anti-vibration mounts are cheap and readily available from UK-based online stores.

They are available in a very wide range of sizes.
You simply look for the mass (Kg) you wish each mount-point to carry, and the size bolt you require.

Do heat-pump installers know about these devices, I wonder?

The ones I discussed the subject with did - but did not rate them highly for all that! Regards, Toodles.

@transparent  I have been thinking about the valves that are not insulated and began to wonder if perhaps this is intentional so started to Google ….. The valves are antifreeze valves that will automatically open and drain the pipes on the heat pump side of the LLH if the temperature drops to 3 degrees C.

 tells me that the valves should not be insulated -  but they should be protected from the weather so I’ll take this up with the installer. Regards, Toodles.

Hi,

Having the same problem was your issue fixed? If so how was it fixed please.

Hi,

We had our ASHP installed about 2 weeks ago.  Hot water and heating all work well and the outside unit is much quieter than I expected it to be.  Unfortunately it's the noise inside the house that's the problem.  There a constant whooshing noise whenever the heating kicks in.  I set the schedule to stop the water heating overnight and have set the honeywell  thermostat to 15 degrees at night to stop the system running at night so I can at least sleep.  This worked until the outside temp dropped below 5 degrees and suddenly the pump started circulating constantly from 11pm until  6:30 am.

We've had the installed back who says it should be quieter and must be residual air in the system which can take time to clear, just keep topping up the system to maintain pressure around 1.6 bar.  I'm hoping this is all it is but it's been nearly 2 weeks and I'm topping up daily yet there are times I fancy it's getting louder and sometimes its so intrusive. I wonder about getting the whole system removed and going back to gas boiler.

Our installer had been very good and he's disabled the frost protection to stop it running at night soI can now sleep but I do worry what will happen in winter, not so much for house temp over night but for potential damage to the ASHP itself.  As far as I'm aware, there is no antifreeze in the system as the manufacturer advises against it apparently.

The system is set to flow temp 46 degrees, we can't use the auto setting as the room thermometer is Honeywell so we've been advised to leave on flow temp setting.

Does anyone have any thoughts?  Is there anyone who's had the same experience and it has settled down or they've found a fix?

Our system is:

Mitsubishi 6 Kw Ecodan Standalone (PUZ-WM60VAA) 150 L cylinder, low loss header/buffer tank.

Thanks 

I have an Ecodan with the Mitsubishi maintenance package and it is a condition of the annual maintenance agreement that glycol is used in the system. It is unusual to hear of a system with the freeze stat switched off when there is no glycol. The installer my have fitted anti freeze valves but I would have thought that the freeze stat would be left enabled. You might wish to raise this with your installer.

https://les.mitsubishielectric.co.uk/the-hub/what-happens-to-a-heat-pump-in-the-cold  

Posted by: @john00foster

↑

Hi,

Having the same problem was your issue fixed? If so how was it fixed please.

Hi,

We had our ASHP installed about 2 weeks ago.  Hot water and heating all work well and the outside unit is much quieter than I expected it to be.  Unfortunately it's the noise inside the house that's the problem.  There a constant whooshing noise whenever the heating kicks in.  I set the schedule to stop the water heating overnight and have set the honeywell  thermostat to 15 degrees at night to stop the system running at night so I can at least sleep.  This worked until the outside temp dropped below 5 degrees and suddenly the pump started circulating constantly from 11pm until  6:30 am.

We've had the installed back who says it should be quieter and must be residual air in the system which can take time to clear, just keep topping up the system to maintain pressure around 1.6 bar.  I'm hoping this is all it is but it's been nearly 2 weeks and I'm topping up daily yet there are times I fancy it's getting louder and sometimes its so intrusive. I wonder about getting the whole system removed and going back to gas boiler.

Our installer had been very good and he's disabled the frost protection to stop it running at night soI can now sleep but I do worry what will happen in winter, not so much for house temp over night but for potential damage to the ASHP itself.  As far as I'm aware, there is no antifreeze in the system as the manufacturer advises against it apparently.

The system is set to flow temp 46 degrees, we can't use the auto setting as the room thermometer is Honeywell so we've been advised to leave on flow temp setting.

Does anyone have any thoughts?  Is there anyone who's had the same experience and it has settled down or they've found a fix?

Our system is:

Mitsubishi 6 Kw Ecodan Standalone (PUZ-WM60VAA) 150 L cylinder, low loss header/buffer tank.

Thanks 

Sorry to hear about what are almost certainly teething troubles, the Mitsubishi is well renowned so its unlikely that there is anything major wrong.  if your installer is being helpful as well it really shouldnt be too difficult to sort it out.

Lets unpack what you have said that so we understand what you are trying to fix

Noise:  From the fact the installer says its air in the system, Im presuming its a gurgling sound.  Please confirm.  It took 4 weeks for the air to come out of my system and there was one radiator where it collected that had to be regularly bled manually.  Your system (like mine) will have been fitted with an automatic bleed valve at or near the highest point, but sometimes air collects elsewhere and it needs to be bled manually.  If you provide a bit more info it should be possible to diagnose.

Frost protection:  There are two levels (at least) of frost protection.

1. The system turns itself on.  This is the primary protection (which has apparently been disabled)
2. Either anti freeze valves are fitted outside near the heat pump or the system has antifreeze (glycol) in it.  This is the secondary protection which kicks in if the power or primary protection mechanism fails.  Your installer should tell you which of the two has been fitted if you ask, which you should.

As long as one of these is in place it shouldn't freeze, but level 2, if implemented using anti-freeze valves, can be a bit inconvenient if it triggers so we ideally need to get to the point where you can turn it back on at night.  

TBH Its a shame about the buffer tank/low loss header, its almost certainly costing you an extra 15% to run as a result. Nevertheless there is certainly some optimisation to be done.  Your most efficient mode of operation is to have it running 24*7 at the lowest flow temperature possible.  What Honeywell thermostat do you have and do you have thermostatic radiator valves?  If you tell us a bit about this we can help with some suggestions to optimise.  However first lets get the noise fixed so you can run 24*7 (possibly with a night time setback) which is generally the way to run a heat pump for minimum running cost.

You may want to read this introduction which explains a lot of the key concepts.

@john00foster

Never did get to bottom of it.  Its just because of where it's sited.  Even a gas boiler engineer has said a boiler would be even more noisy if it was installed in the airing cupboard.  Had I know I might have got additional sound proofing in first.  Although, it may not have helped.  

On the plus side, I don't really notice it anymore and friends don't find it particularly noisy either.

Sorry I've no better news for you.