AAON - 7.5 Ton - where is the clogged filter switch

[Dan_G]

I have an older 7.5 ton AAON unit that I work on ... Model RM-007-3-0-DA01-339. The unit dates from 2007. It has a clogged filter alarm. Not a big deal. I would like to know where the clogged filter switch is located. I'm not sure how to reset this minor alarm and I would like to at least verify the pressure switch is OK ... the filters are new. I do have the handheld service tool and Prism. It was raining today and I could not for the life of me figure out how to reset this alarm using the handheld. Any help would be appreciated.

[buford]

I would think in the blower or filter section. They usually have very good wiring diagrams, i would check there also to see if wires are landed as the wiring shows. its sensing across the filters so should be close around there, or the tubing for it will go across the filters.

[Dan_G]

OK, that makes sense. I just checked the schematic. It has a blue and red wire. I did see a rather large rectangular metal switch in the blower cabinet with a tube that seemed to go over the filters and into the damper section. I did a search and that is apparently a P59900 Pressure Switch. So I'll check that and see if it's working.

[timebuilder]

Remember to post back later so others can learn.

[VAsteamfitter]

The clogged filter switch is located in the return / air filter section of the unit right when you open the access door. Be sure the sensing / pick up tubing is not kinked or dust / debris built up.

[Dan_G]

I'm probably going back in a week or two. I'll check it out. This unit has a few issues. Heat works but cooling is not operational. I'll bring those issues in a separate thread since they have nothing to do with the clogged filter alarm.

[Toolsofthetrade]

Yes most Aaons I’ve seen have the filter switch in the return air/filter section. Should have two pressure tubes 1 routed before and 1 after the filters taking A differential pressure reading. Like VA steam fitter said checking the tubing, they build up with dust and can cause an alarm. Blowing them out often takes care of that

[reeferrat]

Almost every CFS I've seen in an Aaon is in the blower section mounted on the right side of the HX enclosure.


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