mousetarget

It does sound like air in the system, the noise is just constant now it used to come on just 4-8 hours at a time. Don't know about air valves in the system as its totally new to us. It was only serviced 4 weeks ago, don't know about the buffer. We are real novices when it comes to this system, here are few photos of the system. The air/humming sounds seems to be coming from the red valve control area - any ideas so we can sleep tonight?

Its floor mounted but as IanR says its not coming from the SMO20 but seems to be the circulation pump ASHP - there is humming, water noise pretty much all the time today but particularly at night, if you put your ear to the skirting board in the bedroom you can hear the noise more loudly - is there anything we can do? we just can't sleep?

We have just moved into a house with a NIBE SM020 UK system installed with an air source heat pump. The system comes on during the night and emits a low humming sound which unfortunately reverberates into our bedroom. Is there anyway for us to programme the system for it not to come on during the hours of 21.00 - 07.00? We’d still like hot water for the mornings of course if possible, so this may mean the system has to create the hot water before it shuts off at 21.00? Can you help at all as we are unable to get a good night’s sleep?

Thanks for the replies. If indeed my drainage field cannot cope with the amount of water passing through the system, because of rainwater going in, what could be a possible solution and how expensive would it be? Would it be just a case of capturing the water coming off the house roof in water butts so it doesn't enter the soakaway system which leads to the septic tank?, a bit of a pain having to empty them all the time though?

Does anyone recognise this design of Septic Tank system? - I've recently moved to a new home and can't find anywhere with a design like this. The waste pipe runs from the house to the bottom of a very deep, 20ft - 30ft concrete shaft, the water and waste then rises to the top (about half way up is a macerator which can be turned on) and there is a plastic pipe at the top which then takes the excess into the septic tank. I've been told that the builder who put it in also connected it in such a way to allow rainwater to access the chamber which I believe is not recommended. The septic tank is then connected to a drainage field in the garden. I've always understood waste pipes connect to the top of a septic tank, and then the solids can drop to the bottom, the waste pipe from the house connects to the bottom on this shaft which confuses me. See attached rough sketch, has anyone seen anything like this before? The system works fine but just want to understand it more?