Daikin indoor unit 'buffeting' air flow

[Welly]

Hi all, I'm new and pleased to have found a very informative forum here. I'm hoping someone might be able to shed some light on the following problem.

I've got a Daikin RS50BVMB outdoor with an FTS50BVMB indoor unit at home (kinda 'surplus' from a job ). Anyway the indoor unit has been sounding weird like the airflow is running high then low etc. I cleaned the filters which weren't too bad and found a fault code A5 (freeze protection I think) probably due to low air flow over the evap.

It seems to me like the left side of the unit is running interrupted - is there two fan motors inside? one left and one right side? just wondering what could be at fault here - it's like the fan motor is getting an interrupted power supply and only running as and when it can.....

Any suggestions would be appreciated.

Welly

[Tayters]

I've noticed a buffeting noise after cleaning the coils on wall mounts. It seems to be due to the liquid I'd sprayed on, blocking up various parts of the fins around the coil. After a while normal service resumed when the liquid had fully drained out.

The coil should have only one fan motor on it. Are the blades and the coil clean?

Cheers, Andy.

[Welly]

Just the one motor and a cylindrical centrifugal fan then?

I haven't had too much of a dig around yet but there's definately more air coming out of the right-hand side and the left side varies up and down (like a blockage I suppose). I've turned it all off today and it's cleared the A5 fault for now.

Do you think the evap coil is dirty then? I've been a little star with the filter cleaning so would be dissapointed with myself here but I suppose the filters can't trap everything eh?

Would it be fairly straight forward for a knowledgeable have a go type like me to strip the unit far enough to do a deep clean?

[Brian_UK]

Use a torch and have a good look at the fan, there may be something inside the rotor itself.

[back2space]

It seems the unit is a wall mount it seems. I do notice sometimes with wall mounts the fan can make buffeting noise occasionaly like its rotating without any air passing through it.

I think its because the fan is after the coil and has to suck air through the coil.

My unit makes this sound also and I think the casing designs restricts airflow slightly.

However it is one long fan driven by the same motor so air flow should be similar across the whole coil unless the coil is blocked.

How regulary do you have the coil flushed with coil cleaning and rinsed?

[monkey spanners]

I've seen some wall mounts where part of the fan blade was covered in dirt and mold, i noticed this when checking the air of temp on a service, you could feel the difference on you hand, not much air seemed to be coming off the right hand side, washed it out with the garden sprayer and a tooth brush!

[Welly]

Well, I've found the problem!

The fan was caked in crud like a cream coloured thick dust spent three hours this morning with an assortment of modified brushes and it's all done!

The fan was actually out of balance slightly before but now the air flow is strong and steady as a rock

The air buffeting was due to the shape that the fan blades had become and some of the smaller gaps between the blades were almost blocked! that would play havoc with the air flow and pressures.

As said before I've always been really hot on the filter cleaning so surprised by this. It's been in service for three years and spends the warmer 6 months of the year being on 24hrs a day......typing that made me think that's quite a lot then!

I'll post up some pics later (before and after) and thanks to all who suggested stuff and inspired me to dig further into it.

Really chuffed with the results now, just hope the sun comes out

[Brian_UK]

Glad you found the problem.

Now, if you're not doing anything next week I've got a filthy fan in the kitchen of an old peoples home to be cleaned.

Just bring your toothbrush....

[Welly]

Now, if you're not doing anything next week I've got a filthy fan in the kitchen of an old peoples home to be cleaned.

Just bring your toothbrush....

We thank you for your recent enquiry, unfortunately due to our current workload we will be unable to service your requirements on this occasion but thank you for you interest.