Heat Recovery Ventilator (HRV) not forcing furnace fan on

[Hedgehog]

Good day,

I had a Goodman SS-GMV95 furnace, Goodman A/C SS-SSX14, Fantech HRV SHR 1504 installed last month. These are being controlled by a Honeywell VisionPro IAQ thermostat.

My problem is that the HRV will sometimes run without forcing the furnace fan on and other times it does turn on the fan. Why?

This is happening maybe 25% of the time. It seems way more because I am not constantly thinking about it.

It is not defrosting because it is not cold enough yet and I can't see it randomly deciding to defrost itself if it hasn't running through a cycle.

There is a choice on the thermostat to choose between "Vent on will force fan on also", "Vent will not force fan ON". I have it set to the first. So why doesn't it do it all the time?

I know this whole system needs to be installed by a contractor which it was but now he cannot get suppliers to return his calls and my calls to Fantech or Honeywell are the standard "call you contractor" reply.

Any ideas on what to look for or at or anything at all would be helpful.

Thanks. B

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[Hedgehog]

Turns out the problem was that the connection to the HRV was on Timer instead of Dehum.  So what was happening was the HRV was working based on it's settings for Timer.  So it appeared to work sometimes with the furnace and sometimes not.

It is working very well now.

[jb8103]

This connection is at the thermostat?

[Hedgehog]

Sorry, I didn't mean to be confusing. 

There are 4 connections on the outside of the HRV unit: EDF, Timer, Dehum, and Cur SW.

The wiring from the thermostat controller had been attached to Timer which was causing my grief.  When it was moved to attached to Dehum then it started working as it should.

Now what happens when the thermostat calls for ventilation it will click and turn on the furnace fan and turn on the HRV.  They both run for however long is necessary, 15 minutes or so, then the thermostat clicks and they both shut off.

B