Fan runs continuously

[robbieas]

You guys helped me solve a previous problem (Topic: "Incorrect wiring?", Dec 17, 2009 - most of my BMPlus3000 settings are listed in that topic), so I was hoping you might shed some light on a new problem.

My fan appears to get stuck running constantly, even though the BMPlus 3000 doesn't appear to be telling it to run (the fan LED isn't on). This appears to be a new problem in the last 2-3 weeks. I haven't determined any situation that makes it happen, but it seems like everyday at some point I catch it running even though none of the t-stats are making a call. The fan appears to cutoff and cycle correctly for at least some of the time, as I have noticed heating calls complete and the fan is definitely off afterwards. I've noticed the last two nights after all the t-stats change to the night setting where no heating calls should be made, the fan is still running in all 3 zones.

The last 2 times I noticed this, I checked each t-stat, and none were making a heating call and all are on fan auto. I put them all in the off position. I gave the system 5+ minutes to make sure the fan should have definitely cutoff by now even if they were in a heating call. The fan is running and air is blowing in all 3 zones. When I check the BMPlus 3000, all zones appear to be off and the fan LED is not on.

Is there anything I'm missing in the controller setup? What else can I check? Obviously I'd love to avoid a service call if it is something I can troubleshoot/resolve on my own (I'm a pretty handy guy - a Georgia Tech engineer too!) so if you've got any ideas I'd love to hear them!

Thanks a ton for your help... great forum you guys run here!


Regards,
Robbie

[Eric K.]

Robbie,

Did you move the wire which was connected to 'W1/B' to the 'W2/E' terminal as we discussed in your earlier post? If not this could be the cause of the fan running.

If you did move it, then what you are describing is not an issue with the zone panel. Something outside of the zone panel is telling your fan to run.

When this issue is occurring, does the airflow feel heated or room temperature? What may be happening is your heat pump could be going into a defrost mode causing the equipment to run for a few extra minutes to defrost the outdoor coil.

Eric

[robbieas]

I did move the wire connected to 'W1/B' to the 'W2/E' contact a wile back... that resolved my problem up until recently. I believe the fan running continuously is a different issue. If you beleive the panel is not the culprit (and I really didn't think it was) then I beleive I'll need to calll someone out to pin-point what is causing the fan to run full-time.

Do you have a listing of BMPlus 3000 certified technicians I can call? I am in the Atlanta area. If I do have to make a service call, I'd want to make sure they know how to use the BMPlus.

Thanks for your help!

[Eric K.]

Robbie,

Contact Jason in sales at 800-446-3110 ext. 496, he can help you locate a contractor in your location.

Eric