Hej! Det är min första inlägg här men jag har läst ganska mycket på det här forumet. Tack för allt fantastiks info
När blev det kallare, började jag "överventilera" min 12 år gammal Nibe F750 och ökade fläkthästighet för att minska avfrostningar. Det funkade okej men sen fläkten började låta konstigt och irritera mig på natten. Då letade jag här och hittade denna tråd.
Nu blev det lite värmare på helgen och bestämde jag att byta lagret på fläkten. Vill dela hur det gick.
Jag är icke-svensk och inte så van att skriva på svenska så mycket då byter till engelska, förlåt mig, vänner.
So, I found Benjis post very helpful
https://www.varmepumpsforum.com/vpforum/index.php?topic=68988.msg771295#msg771295. I used instructions and images as references in several cases, and it gave me the courage to continue when it was harder than expected.
I already did some smaller fixes on my F750, so disassembling the top part and removing the fan was easy. Also, unscrewing the top cap of the fan was simple. Here's where struggles began:
1. Removing circuit board. Additionally to removing 1 screw, 2 clips, one has to "unclick" two small plastic latches (see them next to ICs).
2. Removing lock ring: fortunately I had small pliers with circular tips which worked best. I still tried to be very careful knowing that the ring is > 10 years old. Eventually, it came out.
3. Detaching the top bearing from axis. It was sitting really tight. Benji mentioned knocking with mandrel and some force. I expected this to go much easier but it was stuck. I carefully used a hammer first, then found something like mandrel. Then, I understood that the best effect comes from just several hard hits instead of gentle knocking. Then the first bearing was out from axis.
I have to say that the whole construction felt rather sturdy once the circuit board was removed, so don't be afraid to give it a bit of force when needed.
4. Expect some magnetic force when removing the core from the motor.
5. Then the hardest part for me came: removing the inner bearing. It sits rather low, in a small space and super tight. I literally tried all the tools I had at home (including a ton of WD40) but it just barely moved up and down 3 mm after an hour. I could see a lot of brown liquid coming out giving a sign that there is corrosion between the axis and bearing but it didn't
. Also, having strong magnets inside didn't
all the metal tools, I also tried to be careful not to damage the magnets.
After an hour of tries, I checked post
https://www.varmepumpsforum.com/vpforum/index.php?topic=68988.msg770609#msg770609 from thenik (you are my hero!) and it mentioned "avdragare". At first, I didn't pay much attention but then I googled and understood what I needed. I found this guy at biltema:
https://www.biltema.se/bil---mc/bilverktyg/avdragare/avdragare-0---75-mm-2000051456. Take the smallest size (0-75), even this one barely fits inside the motor. With avdragare I could easily remove the bearing. There was just a tiny spot of rust on the inside of bearing but it was still enough to make it very hard to remove. Also, apparently, you can use a bigger size avdragare to remove the top bearing from the axis. (see image) I would say it's definitely worth the trip to Biltema and an investment of 250-300 SEK.
6. After this, I cleaned the blades of the fan, they were super dirty (see image).
7. Assembling everything back was relatively easy, no surprises there, just a bit of force needed again to put new bearings in place. I also found one ring which I'm not sure where it was. It didn't look important anyway 😅
After all, the fan is super silent, I can only hear the air flowing
The fan speed increased by ~1 %
With all this, I can now see why it may be easier to change the whole fan. Without instruction like in this thread it's possible to damage circuit board and in general, the process needs some tools and force. Also, the fan and blades were rather corroded, I would say.
Attaching some images for illustration.
Tack så mycket alla
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