Humidifiers and Dehumidifiers - TrueSteam humidifying without furnace fan on

Hello and thanks for reading,
I have had my TruestSteam for 2 months now and it keeps my RH% where I want it. However a few weeks ago I noticed it was on without my furnace fan being on. After a few minutes the blower came on so I didn't think to much of it. Yesterday I was working in my basement most of the day and I noticed it was humidifying without the blower fan again. This time the furnace fan did not come on. Except for these two times, when I see the humidifier on, the furnace fan is also on. So I began investigating my IAQ settings and everything looks good. Setting 374 is set to 1 (humidifier will force fan on). I decided to check the dip switch settings on my humidifier and here is what I found.
http://img155.imageshack.us/img155/4554/truesteamhumidifier012.th.jpg (http://img155.imageshack.us/my.php?image=truesteamhumidifier012.jpg)
http://img410.imageshack.us/img410/6073/truesteamhumidifier004.th.jpg (http://img410.imageshack.us/my.php?image=truesteamhumidifier004.jpg)
http://img5.imageshack.us/img5/5337/truesteamhumidifier001.th.jpg (http://img5.imageshack.us/my.php?image=truesteamhumidifier001.jpg)
From the settings in the second picture above it seems like the humidifier would be allowed to turn on without the furnace fan. Since setting 374 is set to 1, I would think this is OK. I would like to know if anyone has some suggestions? Should I change the dip switch settings so that #4 is off? How will this effect its ability to operate since it is supposed to turn on the furnace fan? Is my ventilator possibly affecting how the Truesteam operates? I would think they are totally independent.

One side question, is there an airflow sensor in the Truesteam that actually checks for airflow or does it just look for the furnace fan to be on?

I did some testing and here is what I found.

I spent some time last night trying different sequences of start ups. Here is what I found.
With heat, ventilator, and humidifier off, when I bump up the humidity setting. The humidifier and the blower fan both turn on at the same time. One thing to note in this situation is that the humidifier had previously been running so it was already hot. Next I left the humidifier on and turned the heat on. What happened was after a second or two the IAQ said "wait" and then it turned the blower fan OFF while the furnace started heating up. The humidifier was still on and the furnace fan was OFF. It took 80 seconds for the furnace to heat up and then the blower turned on again. This seems like a problem.

The next thing I tried was to let the humidifier cool down and turn it on. I did this this morning after lowering the humidity setting overnight to make sure it didn't turn on. My HRV doesn't run during the sleeping hours so I was curious to see how much my humidity would drop due to air infiltration with temps below freezing outside. To my surprise my humidity did not drop from 40% which is good. I believe my ACH to be between .2 and .275. WIth the humidifier cold and no calls for heat being made, I bumped my humidity setting on the IAQ up to 45%. The humidifier turned on saying that it was humidifiying but the furnace fan did not turn on. Granted at first while the water is warming up no steam will be produced but it seemed like the humidifier had gotten pretty hot after a few minutes and the blower fan had not turned on. I wasn't able to wait more than 5 minutes before I had to go to work but this seems like a problem too. I can try moving dip switch 4 to the off setting tonight but I have a feeling that is not going to force the furnace fan on.

Does anyone have any thoughts/recommendations on either of the two situations above where the humidifier is on but the furnace fan is OFF? :eek:

I'm concerned that this will cause damage to my furnace and duct system.

TrueSteam Installation Guide page 18 (20): http://customer.honeywell.com/techlit/pdf/PackedLit/69-2036EFS.pdf

According to the install guide on page 18 (20) referring to dipswitch settings, it states "DIP 4 OFF, DIP 5 OFF: TrueSTEAM will not be allowed to humidify without HVAC power being present." With DIP 4 on, you are essentially allowing the TrueSteam to operate independant from the HVAC operation. So yes, go ahead and place DIP 4 in the off position.

D,

I do know Carrier shut down their fan when there is a call for heat to get the heat exchanger to warm up.

Now on the no call for heat, the IAQ should force the fan ON (374 setting).

I would check for power on G on the zone board.

D,

I do know Carrier shut down their fan when there is a call for heat to get the heat exchanger to warm up.

Now on the no call for heat, the IAQ should force the fan ON (374 setting).

I would check for power on G on the zone board.

I did some more testing last night. If the Truesteam tank is empty and I create a call for humidity then the blower fan powers on right away, but if the tank is already full and I create a call for humidity then the fan doesn't come on. :confused:

I tried setting dip switch 4 to off, and as soon as I did the red call service light came on. I switched it back to on and the light went off. Tried again and the same thing. I can try checking for power on G of the zone board. I made sure all the connections were solid on the zone board and the humidifier.

Yeah, find out about G.. I wouldn't be messing with it anymore since this is new, and is under warranty.

Here is a summary of my findings when there is a call for humidity.

1)Empty Humidifier -> blower fan comes on
2)Full Hot humidifier -> blower fan comes on
3)Full Cold Humidifier -> blower fan does not come on

A special case in my opinion is
4)Full Hot running humidifier -> call for heat shuts off blower for ~80 seconds, then comes back on. Normal operation for the furnace I suppose.

I was told on another forum by beenthere, that it could take 10-15 minutes for the blower to come on when the tank was cold and full. I asked him why, because it doesn't seem like that would be any different than the empty humidifier scenario above.

I did some more testing and found that what beenthere says is correct. I tried this twice. With the tank full but cold, I created a call for humidity. The humidifier started right away and the fan kicked on almost exactly 15 minutes later. I tried it again and this time the fan kicked on about 13 minutes later. While waiting for the blower fan to kick on I could hear the steam coming out of the TrueSteam humidifier. If I had to guess it was about 5 minutes before the blower fan came on. So that's 5 minutes of steam without blower in one case (#3 above) and about 1.5 minutes in the other case (#4 above).

So the net is that the system is operating as it is supposed to??

If there was a simple way to get the blower to come on right away when the humidifier turns on I would be a lot more comfortable with the system.

For extra precaution I can pull out one of my zone dampers and inspect the inside of my plenum.

I tested for power on the G terminal and it was 0V until the blower fan kicked on and then it went to 26.2V

Learn something new everyday!

I know you mention about the R and G wires hooked up, is that still hooked up to the TrueSTEAM?

I"ll have to head that way and see what been said.

I know you mention about the R and G wires hooked up, is that still hooked up to the TrueSTEAM?

I"ll have to head that way and see what been said.

There were four 18 gauge wires going between the truesteam and the my 8835 zone panel. On the truesteam side 2 wires were left hanging and not connected to anything the other 2 were connected to the two hum terminals. On the 8835 panel side all 4 wires were connected up. My guess is that the tech wired the 8835 panel side first and then read the directions and realized that they weren't needed on the Truesteam side. I simply disconnected them on the 8835 panel side to avoid any confusion.

You are welcome to stop by any time.

I'm in contact with Haley Comfort systems who did the install. I've sent them my findings and am waiting to see what they think.

Here are some of my IAQ settings. I really think that 374 being set to a 1 should force the fan on immediately no matter what the state of the humidifier. Maybe this is a problem with the IAQ stat:
370 - 1 (indoor humidity sensor in t-stat)
372 - 3 (Humidify with frost protection)
374 - 1 (humidify will force fan on)
379 - 0 (no dehumidification control)
400 - 2 (ventilation on except during sleep)
404 - 30 (Max ventilation percentage limit 30%)
405 - 2 (Vent on will not force fan on.)
*notes on 405* My intake goes to my supply and my outtake comes out of my return. I've tested the back flow with a piece of paper in place of my AA5000 filter and didn't notice much of anything. Also, it drops my relative humidity at a good rate.
406 - 1 (Ventilation when high humidity, with frost protection set to 5)

Link to IAQ install manual which lists the t-stat's options.
http://www.hotfreshcool.com/Product/...0Guide%201.pdf

I really think that 374 being set to a 1 should force the fan on immediately no matter what the state of the humidifier.
Correct, Since just the HUM is wired up, the IAQ should force the fan on no matter what.

Correct, Since just the HUM is wired up, the IAQ should force the fan on no matter what.
You are correct Jay. The contractor that installed my TruesSteam said that Honeywell said given my IAQ settings the blower fan should turn on immediately whenever there is a call for humidity. He said without viewing the equipment he suspects the problem is either with wiring or with the IAQ system. He didn't mention anything about situation #4, where the furnace fan shuts off for ~80 seconds while the burner heats up to provide heat.

Yeah, something is up, and as stated, can be a few things with knowing for sure till a meter is put on to see where the power is lost to keep the blower running.

I have the HVAC specialist coming out next week. In my continued discussions with them about this, they said that the operation described above might be due to this:

"A solenoid that opens when the steam is ready to be injected that turns on the fan. If the tank is empty it probably heats instantaneous as it passes through."

That seems like a reasonable explanation for the delayed fan turn-on when the tank is full and cold.

I should note that only the hum-hum terminals are used on the 8835 zone board to connect into Truesteam humidifier.

And here's where I think the explanation falls apart. With only the two wires connecting the TrueSteam to my 8835 board isn't it just an open or closed contact and that is determined by the VisionPro IAQ stat or is there communication that the TrueSteam sends to the 8835 through those two wires that says "HEY, I'm ready to steam, go ahead and start the blower!!"? The TrueSteam is not wired to the furnace board in anyway.

Then one would have to question why the blower comes on right away when the tank is empty.

On the 8835, the HUM is just a dry contact. When the IAQ calls for humidity the contacts closes, and the circuit completes on HUM on the TrueSTEAM.

In your IAQ settings, it set to "Force Fan On", the fan should come on no matter what.

On the 8835, the HUM is just a dry contact. When the IAQ calls for humidity the contacts closes, and the circuit completes on HUM on the TrueSTEAM.

In your IAQ settings, it set to "Force Fan On", the fan should come on no matter what.

Thanks Jay. That's what I think too, but I'm being given the line that other things should be investigated first. They want to test if steam is coming out before the fan actually comes on and yes that might help put my mind at ease but it doesn't explain why the system isn't functioning properly.

The tech came out and reviewed the wiring. He said it looked correct. Unfortunately we couldn't reproduce the cold tank/delayed fan turn on case. We had a full cold tank (~65 degrees) but the fan came on right away which is what it is supposed to do. Never the less, we took a zone damper out and monitored the output of the truesteam nozzle in the plenum. It took a little over 10 minutes to put out any significant moisture. This puts my mind at ease somewhat knowing that it's unlikely there would be any significant moisture buildup before the blower turns on. I had a model 40360 venmar control installed. It interfaces with my 8835 zone board to control my air exchanger . When I get time I'll test the humidifier again, to see if my old ventilator control caused my blower fan problems, unlikely though.