NIBE SMO20 UK - Humming Noise when in operation at night
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?
Do you have the user manual? If not you can download it from https://www.nibe.eu/en-gb/assets/documents/8307/231759-1.pdf. If link doesn't work, just google it. In there you will find instructions about scheduling, though they are not necessarily easy to follow!! It depends on your particular set up e.g. floor sensors or not. We don't turn our heating off overnight but once we were doing it as an experiment and the installer had to help us. I seem to remember it was something to do with putting in the times and the temperature at which you allowed the heating to start, so he set ours to -10C!! I know, sounds crazy. Water heating is set separately and is easier to set up.
It sounds as though the heating is coming on overnight because it is set to work on weather compensation. During the day the temperature will be high enough for the heating not to come on but during the night as the temperature drops the heating kicks in. You can switch the heating off altogether. See page 40 in the manual - Menu 4.2 - Operating Mode. The default is Auto but you can change it to Manual and then deselect 'heating'. This allows the system just to heat water as required.
However, it's probably more important to work out what is causing the humming noise as during the winter you will probably want to keep the heating on overnight, especially if you have underfloor heating. You will hear the mantra 'low and slow' i.e. run heating at lower temperatures constantly. (As an aside, once we mastered that approach our heating bills went down.)
When the heating comes on it could be the pump that is humming. How many pumps do you have? I have no understanding of how to deal with noisy pumps but there are many of this forum who will be able to advise as it probably doesn't matter which ASHP make you have.
I hope this helps.
Welcome to the forums @superduck
Looking at the manual @lizzie provided you can do the scheduling you're after – see below. But as Lizzie has stated, it's fine to do that at this time of year, but this isn't a solution going into the winter, so I'd recommend you try and identify where the reverberations are coming from and sort that out.
Tp address your immediate questions, you can program your NIBE SMO 20 system to avoid running during the night between 21:00 and 07:00 while still ensuring you have hot water in the morning.
1. Scheduling Hot Water:
• Go to Menu 2.3, “Scheduling Hot Water.”
• You can schedule two different periods per day. For instance, you can set a schedule to ensure hot water is ready before 21:00.
• Select “activated” to enable the scheduling and set the desired times for hot water production.
2. Silent Mode:
• To reduce noise during the night, you can schedule the compressor to operate in “Quiet Mode.” Go to Menu 4.9.6, “Schedule Silent Mode.”
• Activate the scheduling and set the quiet mode to run during the hours you wish to minimize noise, such as from 21:00 to 07:00.
3. Blocking Additional Heat:
• If needed, you can also block additional heat to ensure the system doesn’t come on during the night. This can be done in Menu 4.9.5, “Schedule Blocking.”
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor Thanks Mars for coming in on this. I tend to lurk rather than participate and have learned a lot from the forum. However, there doesn't appear to be many NIBE owners to provide support so I felt I should make an effort even though my expertise and knowledge is limited.
Just a comment on additional heat. As I understand it, additional heat operates only when the ASHP is supplemented by another source of heating (electric/oil/gas) and the ASHP isn't sufficient to meet requirements. The main purpose of it would be to use an immersion heater for the periodic hot water increases to prevent bacterial growth, which should be scheduled. I don't think that should be coming on except for that purpose.
Thank you so much for your detailed replies - much appreciated.
The humming noise seems to be most noisy in the pipes in the skirting boards but it starts in the boiler room - it has now been happening for 2 days solid which suggests it’s not part of the system warming water. It sounds like air/water rushing?
@superduck I can sympathise as I find low level humming noises disturbing too. This sounds like it is something to do with the way the system has been installed. I have no expertise in plumbing and heating installations but hopefully someone who does will pick this up and ask the right questions to help you track it down.
@editor Mars, could you possibly tag some members who can help with this? Thanks. Lizzie.
Posted by: @superduckThank you so much for your detailed replies - much appreciated.
The humming noise seems to be most noisy in the pipes in the skirting boards but it starts in the boiler room - it has now been happening for 2 days solid which suggests it’s not part of the system warming water. It sounds like air/water rushing?
I would suggest that you start by bleeding the radiators and topping up the system.
Is the humming continuous or is it only when the water pump is running?
Posted by: @lizzie@editor Mars, could you possibly tag some members who can help with this? Thanks. Lizzie.
I may have to refer this off our website to where I interact more with installers. Had a few days off with family, and will be on the case this week.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
Thank you so much everyone for your help with this.
the system was set at 18 degrees to kick in, so at night it would start and then create the humming in the pipes in the bedroom - so we changed the temperature to 10 degrees and the sound has stopped and we can sleep again! So the system is working normally, we might just have to open some valves on the radiators to see if the noise lessens when the temperature drops at night
I am pleased that you can once more sleep.
I would suggest that you should now try to identify the root cause of the noise, so that it may be possible to rectify the problem before the heating season starts.
If, as you say, the noise appears to emanating from the pipework, then it could be one of several causes. Pipes don't vibrate and emit sound by themselves, so there must be another cause.
Is the water pump speed too high? This can cause vibration and noise in the pipework.
Is there any air within the system? Have the radiators been bled?
Is the water pump correctly installed? Has the pump been left hanging on the pipework or mounted securely? Where is the water pump located?
- 22 Forums
- 2,073 Topics
- 45.5 K Posts
- 57 Online
- 3,351 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
RE: What’s the modern take on advised types of insulation?
@jeff I am sorry @jeff if I have misunderstood what you...
By Toodles , 15 minutes ago
-
RE: Why Your MCS-Certified Installer Might Not Be As Competent As You Think
Sure thanks will do, much appreciated
By adisharma , 46 minutes ago
-
RE: 5 Star Service from Havenwise
@sheriff-fatman Good post. I am also considering Hav...
By Morgan , 5 hours ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
@editor Cobbler’s Mantra that!
By Toodles , 6 hours ago
-
RE: Radiators downstairs are cooler at the bottom after ASHP install
@melonbuffet This is great assuming now the down stairs...
By ASHP-BOBBA , 24 hours ago
-
RE: Commencing on an ASHP Installation Process
@jamespa Thanks for your input into this thread so far....
By Sheriff Fatman , 24 hours ago
-
RE: Renewables & Heat Pumps in the News
Australia Blue, the first wind farm in Western Victoria...
By Morgan , 1 day ago
-
RE: Ripped Off: How UK Homeowners Are Paying Gas Prices for Wind Energy
The challenge is who pays, who holds the debt and the i...
By Jeff , 1 day ago
-
RE: Flow rate discrepancy between ASHP and manifold
That's useful thanks, I hadn't seen that table before. ...
By AshRolls , 2 days ago
-
In principle I agree, @johnmo, but with provisos. The...
By Majordennisbloodnok , 2 days ago
-
RE: Heat pump installation and BUS Grant timings
@jamespa Thats how I understood it too. 🙂
By ASHP-BOBBA , 2 days ago
-
RE: Antifreeze top up for my heat pump - is this a rip off?
@sallyl That sounds about right if they are re-filling ...
By Brendon Uys , 2 days ago
-
RE: Enabling WiFi: Samsung ASHP on Smart Things App
I would switch it off and see if anyone noticed. We use...
By Anonymous 5011 , 3 days ago
-
I wouldn't be so sure about that. Heat pump designers ...
By JamesPa , 3 days ago
-
RE: Jokes and fun posts about heat pumps and renewables
@toodles they're a rowdy bunch!
By Mars , 3 days ago
-
RE: Home energy storage & battery register
@jamespa To a certain extent, by exporting to the grid ...
By Toodles , 4 days ago
-
RE: Forum updates, announcements & issues
@editor Fairy Nuff Mars, I doubt that my ramblings woul...
By Toodles , 5 days ago
-
RE: Confusion about heat pump sizing
We’ve published a deep dive into heat pump sizing, and ...
By Mars , 5 days ago
-
We’ve published a deep dive into heat pump sizing, and ...
By Mars , 5 days ago