Hi folks,
for the first two weeks my printer was pretty much running 24/7. Now, as the first excitement fades, I was wondering where the noise comes from in standby.
I figured out it was the PSU fan (in standby, hours after a print) and opened a ticket.
I was assured that it is normal that the fan -even in standby- is constantly on. I find this quite unsettling as no of my other printers do this.
So - H2C users: is your fan always on?
The power supplies they use for some reason have some wild coil whine when not being used
No - I am not talking about a buzzing or high pitched electricity sound. It is literally the fan that is always on.
The H2D’s fan always seems to run also.
Now imagine my confusion when I had 2 x H2S’s purchased 2 months apart last year and one did exactly what you say, and the other one was completely silent.
I also raised a ticket.
My later H2S and H2C do have an idle fan so just assumed this is normal.
This sucks. I know it is not a big thing but as I know the sound is there - I now cannot unhear it. I am a hobbyist- so the printer is idling quite a lot.
The power draw in idle is also quite high - around 20W with Display and lights off. That is nearly 1kw every two days….around 50€ extra electricity per year.
I am not an expert - would it be bad for the electronics if I put the cable into a (3600w) smartplug? This way, I can access remotely, and save on power and nerves.
This is weird. On Reddit are a few users with the same issue on H2D/H2S in which Bambu has replaced the PSUs as well as whole printers.
Now it is expected behavior.
it’s not an issue though, its just a psu fan spinning.
It’s an issue if the printer is in your office and constantly makes a noise when it’s technically off.
Yeah sorry I get that. I meant from a mechanical point of view, its not an issue. There is nothing at fault.
It’s just a minor inconvenience, something that Bambu can’t/won’t do anything about sadly.
I do exactly this I do not have any issue with it since about 6 months. My H2D (now H2C) is plugged into a smart plug. I can remotely turn on the printer and start print jobs via the App.
Yeah, this is the way I suppose. I still do not get why the PSU will not turn off the fan when there is no load - my A1 next to it does it.
There are a few guys who upgraded with a Noctua fan - I will look into this one day.
As the printer is pulling lot of power (A1=6w btw), having it behind a smart plug seems like the best choice.
the average idle power draw of the h2c is similar to the average power draw of a single led light bulb its so miniscule it almost doesn’t matter
There is a load. When the printer is idle it’s not using power for the steppers and heaters, but all the other electronic components are still using power, like the MCUs that control the mechanics. The power supply gets hot, the fan has to run to keep things cool.
The solution to this problem is simple - turn the printer off when you’re not using it. Save you a few pennnies on your electric bill, too.
The idle power is around 20w with lights off. 25w+ with the light on. I do not consider this miniscule for something that is on standby and sucking power for 365 days a year. That is around 10% of the electricity consumption of an average single household.
I have the old A1 right next to it. I assume it also has steppers and and a MCU? This is absolutely silent and draws 6W. Very comparable to, for example a PS5 in idle mode. The competitive product - the XBOX - also draws around 30W for the same functionality.
This is just not well thought through.
Well the fan uses only about 5 of those watts and for me 25 watts for 365 is less the $15 a year or less then 4 cents a day
I am very happy for your cheap electricity! Again for me and most people in Europe this sums up to around 55$ per year.
The point is still - that is just too much. Bambu did better before, with other models.
Just found another thread on the power consumption Why does the H2D have such high standby power consumption? - #23 by Mr_Miyagi_Wax_On_Wax
Wait your H2C has quiet idle PSU? When did you get it and which country, if I may ask?
My H2C which arrived early Dec. '25 in the US does not, fan runs all the time. If there’s a replacement PS available then it may be of interest to some users.
I didn’t open my printer to check, but the replacement PS model listed on the US BL store for H2 series is a Moso MS-AT460J240-350B0 https://sps.mosopower.com/product/e30-350w-series/ & “datasheet” @ https://p.globalsources.com/IMAGES/PDT/SPEC/943/K1213001943.pdf
Which AFAICT doesn’t have adjustable/idle fan speed. Also the efficiency is kinda crap by modern standards, which to me is a bigger issue. But at least it has PFC.
I do agree it would have been nice if the PS was smarter with the fan. And more efficient.
The fan control is a function of the power supply they happen to use at the time, which I can imagine could vary based on availability or other factors, besides cost of course. There are some simple mod kits for PS fans that don’t already have this feature, which involve a thermistor and variable resistor, though of course that requires some tinkering.
The printer doesn’t notice or care how power is applied. A remote-controlled power relay/switch/plug/whatever is equivalent to physically disconnecting or connecting line power, like pulling a plug or flipping a physical switch. As long as the remote-controlled switch/outlet is rated at least for the power required (eg. 15A at your line voltage), there is no major practical difference.
However, introducing any extra device, wire, or even solid connectors between a power consumer and the power supply introduces resistance and to some extent wastes energy via generated heat. Every extension cord or outlet multiplier literally costs money and reduces the power available to the connected devices. Small or even minuscule amounts in most cases, but not zero (though any high-draw device will caution you to connect it directly to a power outlet w/out ext. cords/etc). That’s before even considering that any “smart device” will need to consume it’s own power to remain on and functional, and of course will also cost money up front, introduce a possible failure point, etc.
Anyway, sorry for the lecture, my point is simply to be careful when choosing apparent fixes or workarounds.
-Max
You do realize that changing just the fan won’t stop it from working, fans just don’t run on their own.
If a printer is on, it’s using power, and if the fan is running, it’s also doing a job of keeping the circuits in your PSU cool. Why, so it lasts longer. I myself would like a healthy PSU. Also, if you’re not using your printer, when the fan is on and ann0 you, turn the printer off. It’s takes 15 seconds to turn on again if you want to use it. Some people like to die of the most trivial hills.
??? Mine sucks 20W constantly if he’s idle with lights off … what LED Bulbs are you running? ^^