TrueSteam humidifying without furnace fan on

dgbehrends · 03-16-2009, 12:01 PM

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.

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?

**beenthere** · 03-16-2009, 12:36 PM

Your suppose to install an optional air flow switch.
There is none in the TS, nor does HW give you one with it.

Its a safety incase of a blower failure. It doesn't flood your system, and do more harm.

You have to leave it set up the way it is until you install a air flow switch/sail switch.

Also, all low voltage wire connections should be rechecked, one could be loose.

dgbehrends · 03-16-2009, 12:40 PM

Quote:

Originally Posted by beenthere

Your suppose to install an optional air flow switch.
There is none in the TS, nor does HW give you one with it.

Its a safety incase of a blower failure. It doesn't flood your system, and do more harm.

You have to leave it set up the way it is until you install a air flow switch/sail switch.

Also, all low voltage wire connections should be rechecked, one could be loose.

Thanks BeenThere. That is very good advice. I will recheck all of the low voltage connections. And look into an air flow switch/sail switch.

dgbehrends · 03-20-2009, 03:41 PM

I spent some time two nights ago 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 did some more testing last night and here is what I found.

When I emptied the tank and then created a call for humidity the blower fan powered on right away as the tank was filling. Then with the tank full I made sure there was no call for humidity and everything shut down properly and water stayed in the tank. (Water stays in the tank unless a 48 hour period of no-humidification passes and then it empties. It also empties for cleaning purposes after every 10 hours of humidification.)

Then with water in the tank I made a call for humidity, and just like above the blower stayed OFF and the humidifier turned on. This is the case I'm most concerned about.

I tried turning dip switch 4 to the off position. As soon as I did that the red call service light came on. I switched it back to on and the red call service light would go off. I tried flipping the dip switch again and the same thing happened. So for some reason it won't let me set dip switch 4 to off.

To summarize what happens when I make 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. This is probably normal operation for the furnace.

I checked the two wires in between the humidifier and Envirazone 8835 panel and they seemed solid. I checked the rest of the wires on my Envirazone 8835 panel and they seemed good as well. I should probably check the furnace board too.

Anything else I should try?

**beenthere** · 03-20-2009, 04:02 PM

It can take 10 to 15 minutes for it to turn the fan on, when it gets a call for humidity, and the tank is cold.

dgbehrends · 03-20-2009, 05:47 PM

Quote:

Originally Posted by beenthere

It can take 10 to 15 minutes for it to turn the fan on, when it gets a call for humidity, and the tank is cold.

I don't see why this needs to be different from the empty tank scenario I listed above. It doesn't take 10 minutes to create the steam (or does it?). Why would the system wait that long to turn the blower on?

**beenthere** · 03-20-2009, 06:02 PM

It does take 10 to 15 minutes to make steam from a cold tank.

It takes 970 BTUs to vaporize 1 pound of water, after that water is at 212°F.

1 pound of water, is roughly 1 pint.

dgbehrends · 03-21-2009, 09:56 AM

I did some more testing and found that what you say 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 your saying 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.

Thanks for you help.

**beenthere** · 03-21-2009, 11:44 AM

You might be hearing the water start to boil off of the element, and not actually hearing steam being produced and put into the duct.

You can have the blower sart with the steam call.

Tell the IAQ to turn the blower on.

But, don't tell the humidifier, to stop controlling the blower.

That way, the blower will start as so as the IAQ calls for humidity, but the Truesteam will keep the blower running to purge the steam after the humidity call is done.

dgbehrends · 03-21-2009, 12:40 PM

Whey you say tell the IAQ to turn the blower on, I believe you are talking about setting 374 which I think I have set correctly. Please correct me if I'm missing something.

Here are some of my IAQ settings:
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

**beenthere** · 03-21-2009, 02:25 PM

You got it.

That should take care of any risk of steam without the ran on.
With the exception of a fan failure, or plugged air filter.

dgbehrends · 03-22-2009, 07:23 PM

That is what I feared. I've been running with those settings since I had my TrueSteam installed, and I still see the behavior where it takes 10-15 mins to turn on when the tank is full and cold. It sounds like you would expect the fan to come immediately with the IAQ settings I have above. The fact that it does not, means it's time for a service call unfortunately.

**beenthere** · 03-22-2009, 07:28 PM

Keep us updated.

dgbehrends · 03-26-2009, 12:48 PM

Quote:

Originally Posted by beenthere

Keep us updated.

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. I'll post more info after I have a tech review the wiring and make a determination if there is a problem with any of my IAQ parts.

dgbehrends · 04-22-2009, 06:01 PM

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 logical explanation for the delayed fan turn-on when the tank is full and cold.
Does that make sense?
I should note that only the hum-hum terminals are used on the 8835 zone board to connect into Truesteam humidifier.