Fujitsu Air Conditioner Troubleshooting

I need your help with Fujitsu air conditioner troubleshooting.

If it didn’t turn on when you turned down the thermostat, make sure it isn’t still set to heat. You have to actually switch on the AC in many homes.

I put that in the category of common sense.

If it stopped running and then came back on, the compressor of a Fujitsu AC is designed not to run for three minutes so it does not blow out the fuse. If it just died and didn’t come back, see if it did blow out a fuse.

I can check that.

If you had a power interruption or just a brown out where it stalled the AC but the lights were still going, the Fujitsu AC protection circuit will keep it off for three minutes by design.

So wait a minute or three to see if it comes back on, and if it does not, check the fuses. What if waiting and hoping is not enough?

If it is noisy, listen to see if it is something in the ducts, extra rattles that suggest something in the unit is loose, noise that goes away in three minutes because it is the sound of coolant flowing at the start or sizzling.

It is an AC, it should not sizzle.

If it has a heating operation, you may hear sizzling, especially if it had to turn on automatic defrost.

This is not something I heard once the first time I turned it on.

If you hear sizzling periodically, get a tech to check for a refrigerant leak that is causing it to ice over before it loses all the refrigerant. Then the noise will stop because all it can do is circulate warm air.

I wonder if that’s responsible for the smell.

If you smell something burning plus noises, turn it off in case there is metal rubbing on metal, wires shorting and burning insulation or another fire hazard. If it is a mildew smell, change out the filter.

I probably need to change the filter, but that ought to be a dusty or musty smell, not this.

If the unit does not get enough air flow as the filter clogs, you’ll get humidity building around the unit. Wet, cool and dirt equals lots of nutrients for mold and mildew, hence the smell on the air that does escape.

At least changing the filter is one of the things I can do myself.

If the air flow is varying, it may slow down the air flow during defrosting, or it may not move much air if you put it in super quiet.

It is a Fujitsu, not a Goodman. Compared to that brand, even at full blast, the Fujitsu is quiet.

If it is too quiet, check the timer or thermostat, because either being off will turn it off.

You’re on to something there.