[bronco]

I installed an Aprilaire 600 humidifier but am having trouble wiring it to the furnace. I have a Lennox C35 furnace with an icomfort thermostat.



I attached a pic of the furnace circuit board.



Anyone hooked one of these up? Any help would be appreciated.

 

[user_12345a]

the c35 is your coil model, post the actual furnace model number.

with comfort-net stat, will need to specifically follow manufacturer's instructions.

someone on here said a isolation relay is needed for some lennox furnaces when using comfortnet.

 

[bronco]

Lennox furnace Model SLP98UH110XV60C-09.

Lennox icomfort thermostat


Thanks

 

[surferdude2]

Connect per the blue outlines. You Aprilaire is a 24 vac bypass humidifier and will be controlled by the icomfort stat... no further controls or transformer are needed.

 

[bronco]

Thanks surferdude2. That's way easier than I had thought. I'll hook it up tomorrow.


Really appreciate the help.

 

[surferdude2]

The icomfort stat makes it so easy that it's baffling!! :wink2:

You'll probably have to program the icomfort to get it sociable with the Aprilaire.

 

[bronco]

I figure anyone can do things the easy way. It takes a real master to figure out how to make it as difficult as possible.:wink2:
Got it all hooked up and talking with the stat, and it works!


The stat manual makes it sound like the unit needs to be calling for heat before the humidifier will work unless I connect an outdoor sensor and use precision mode. Is that correct?

 

[bronco]

I guess if you push buttons long enough, the system will eventually figure out what you want it to do. Works like it should now.



Thanks for all the help.

 

[surferdude2]

When engineer speak gets transcribed by a technical writer, it often leaves the beauty of simplicity behind.

Operate the humidifier in Basic mode and you'll be very happy with it. It only operates when the thermostat is calling for heat... that's precisely what you want. That's how humidifier are designed to work.

The short answer as to why they have that feature is... some older homes have poor insulation and single pane windows, which makes dew pointing a huge problem at very low outside temperatures. Windows tend to sweat and inside walls get wet and mold can form. Most newer homes won't have that problem and most owners of older homes can handle it by manually setting the humidity level higher... no automation needed and no outside temperature sensor either.

In reality, you'll actually be getting that feature, even in Basic mode, since the icomfort stat will check and retrieve the local temperature via the internet. That's accurate enough.

 

[user_12345a]

The stat manual makes it sound like the unit needs to be calling for heat before the humidifier will work unless I connect an outdoor sensor and use precision mode. Is that correct?

Bypass humidifiers don't work properly when the heat is not running unless run on hot water which is very wasteful.

Your furnace is a modulator and should be running very long cycles*, so the humidifier should have no issue keeping up. If it does, it was installed wrong or the house is too lucky.

*Now, the 110k furnace you have is probably oversized unless you have a huge house, it's an enormous amount of heat.
So you're probably not getting the full benefit of having a modulator, which is continuous operation thorough most of the winter at 40-50% capacity.

 

[surferdude2]

Most newer homes won't have that problem and most owners of older homes can handle it by manually setting the humidity level higher I meant LOWER... no automation needed and no outside temperature sensor either.

I can't blame the autocorrect for that one. :biggrin2: The mind is a terrible thing to lose.

@user12345a I wondered about that 110k furnace but decided someone from Montana probably has a better idea about what he needs when it hits -50° F. than a dude from southern Illinois does. :wink2:

Now you being from Canada may have a better idea about that. Someone once told me there were actually some parts of Montana that had very mild winters, around -30° F. or thereabouts. :surprise:

 

[bronco]

Bypass humidifiers don't work properly when the heat is not running unless run on hot water which is very wasteful.

Your furnace is a modulator and should be running very long cycles*, so the humidifier should have no issue keeping up. If it does, it was installed wrong or the house is too lucky.

*Now, the 110k furnace you have is probably oversized unless you have a huge house, it's an enormous amount of heat.
So you're probably not getting the full benefit of having a modulator, which is continuous operation thorough most of the winter at 40-50% capacity.

It's a fair sized house, about 4100 sq ft, and it does get a little chilly now and then:smile:. I know the humidifier is a little small for this size house, but the steamers didn't seem to offer much more water output for the complexity and cost (according to the HVAC company that installed the furnace). I don't really mind the dry air, but my wife's new wood floors don't care for it at all:sad:

 

[user_12345a]

Big houses are hard to humidify - more air exchange in absolute terms relative to moisture production unless you rent out lots of rooms or have a large family.

The april air 600 is definitely small - pretty much all of them are.

The furnace sizing could very well be in line.

 

[user_12345a]

I can't blame the autocorrect for that one. :biggrin2: The mind is a terrible thing to lose.

@user12345a I wondered about that 110k furnace but decided someone from Montana probably has a better idea about what he needs when it hits -50° F. than a dude from southern Illinois does. :wink2:

Now you being from Canada may have a better idea about that. Someone once told me there were actually some parts of Montana that had very mild winters, around -30° F. or thereabouts. :surprise:

My climate is closer to yours than montana's - design temperature around 0F and it never drops below -13F and it only gets that cold a few hours every few years.

75 to 80k output furnaces heating 3000++ sq ft houses here.