This is this morning's graph i’m set to 50 degree. Going to be at least an hour in winter although start temp is a factor. I don’t know what the water temp was last night but dish washer had just run, i had a shower.

I also heat water overnight so length doesn’t bother me,  i do sometimes turn it on fir an hour when grand daughter wants a bath and everyone has showered but its never longer than an hour boost.

we are now in summer so the heating is turned off. It is costing me 25p a day to heat my water 300l tank 4 adults. I’m currently negative cost on my electricity due to batteries, big solar array and iog.

anyone with a noisy cosy try hush mode unbelievably, so happy i switched to a heat pump my bills have more than halved namely due to iog, solar and batteries plus losing gas standing charge. Ps according to octi-aid app my off peak is currently 99%.

i would add you lot on hear really helped me it was so so depressing and a little reassurance and seeing others in the same boat gave me hope it would get sorted.

Hey all, been a while. So the Octopus poeple didn't find any problem, and I ended up just paying up as I didn't want to pursue some kind of dispute through a regulator. I still have the noise issues, but as far as I can tell, the majority of it is from the neighbours. 

One one side, there's a loud, 26 year old boiler, and on the other side, the neighbours are finishing up a loft and rear extension. I think think they've installed something, possible their large america style fridge, which intermittently causes a buzz.....

So all in all, still living in a very shitty situation.

Really sorry to hear that although I must confess to being faintly amused that the prime source of noise turns out to be the neighbours' gas boiler and a fridge, given that this is  in a discussion about noisy heat pumps and with the view still put about that heat pumps are noisy.  Perhaps you should suggest that your neighbour with a boiler gets a heat pump in order that he stops disturbing you with noise!

My neighbours objected to my planning application for a heat pump on noise grounds.  Eventually permission was granted and they told me 6 months after it was installed (the six months covering November-May) that they didn't even know I had it.  In the mean time I have to put up with a constant high pitched whine from their swimming pool circulator pump all through the spring and summer.  

So did I. I thought the vibrations were passing through the circulation pump into the pipes, but this resonance thing seems to happen (to a lesser extent) even when the pump is off.

Does it disappear when the heat pump is off?  What about when the fan and water pump on the heat pump are running, but not the compressor(which will happen at times during cycling).

Are you absolutely sure it's the heat pump.  Sorry to ask!  Once one becomes tuned into noises they can become more obvious than they were previously.  I didn't hear my dishwasher at night until I got a heat pump, then, presumably because I was listening for noise in the early days, I started to hear it!  Weird psychology I know, but nevertheless the case.  I live in a fairly quiet area but still at night there is, depending on wind direction, a low pitched hum from somewhere, possibly just distant road noise filtered by the fabric.  I'm more conscious of that than I was pretty heat pump!

I would focus on the original source of the noise which I thought you said was the pump.  Is it?

So did I. I thought the vibrations were passing through the circulation pump into the pipes, but this resonance thing seems to happen (to a lesser extent) even when the pump is off.

It's also very subtle, the engineers who came were saying they couldn't hear it. Even I can barely hear it, but the problem is that when it's all quiet at night it makes it very hard to sleep, and when I'm in my study for a couple of hours, my ear starts to hurt really badly, and then hurts for hours after leaving the study.

Octopus replaced my old pump :

With a smaller one like this:

They even put in some kind of rubber bracket to reduce the vibration.
I thought it made a difference, but maybe it was a placebo effect, cos it's now noisy again.

I am at a loss, I don't know where to look for the source of the noise. 

I'll read the article and try to undo the balancing right now.

Balancing can be a long process (it can also be very quick especially if the settings are almost right) and its possible to mess things up if you turn down LSVs too much.  If you are happy with the temperature I advise you to leave it unless you have positive reason to suspect its causing a problem.  If you wanted to you could, without changing anything, check that at least one radiator has its LSV fully open.  It would usually be the one furthest from the heat pump or one nearby.   Its important that at least one LSV is fully open and everything else is balanced to that, otherwise you are creating unnecessary restrictions which compromise performance and increase noise. 

Elbows in pipework may exacerbate noise, but are unlikely to be the cause unless the radiators are so poorly balanced that a disproportionate flow is going through one or two rads.    But if this were the case you would notice it in the heating characteristics.  If it is causing it here, the noise will be especially apparent.  Is it.

I would focus on the original source of the noise which I thought you said was the pump.  Is it?