Whole House Humidifier

Correct. Steam will use electric to do so. The good thing with steam is you don’t have to have the furnace running to get humidity. The steam can run just the fan to push humidity on its own. It has its own purpose and isn’t necessarily for everyone’s situation. The evaporative have worked for years as you said. They’re just coming up with new ways to do it.

 

Our new to me home has a whole house humidifier, but it doesn't work. it a aprilaire 500m. It's about 8 years old. The filter is clean as I changed it before the season, and the water line and water filter is supplying water to the solenoid.

What should I be looking at first in diagnosing it, or should I replace it?

 

Did you set the humidistat to test/reset (must be when the blower is running) to see if it works?

 

Check the two leads that go to the water solenoid. If you get 24v & the water still doesn’t trickle you need a new solenoid.


Sent from my iPhone using Tapatalk

 

I checked and all I get is 1V. The transformer puts out 19v. Obviously I stayed at a Holiday inn Express. So I don't think it's even getting the current to open the solenoid.

Sent from a smatrphone

 

Can't find a picture of the one I have, but, it's similar to this. https://www.sylvane.com/skuttle-86-...dv=c?msclkid=00c9aa82d30511e5b440f0c90b4eae62

Not mine...a pic I found online.

It hangs Just requires a cut in the ductwork, running some low v wiring, and getting a water supply. My annual maintenance includes shutting off the water supply, draining it, and making sure all the piece/parts are clean by soaking in vinegar. Had to replace a couple parts, but, it's been running for 18 years. I know it's not the best, but, I think it's better than nothing.

 

Then replace the transformer with a 120v 40va and see if that fixes it. You can also give the solenoid 24 straight from the transformer as well to test. You could be not getting it if you aren’t testing while it’s calling for heat

 

We call those the mold rollers [emoji23][emoji23]

 

Sorry I'm late to the party.

Aprilaire is kind of the standard, but they're very basic and haven't changed much in the last 30 years. We primarily use Honeywell. The "Trueease" models have a little more tech and waste less water. They also use a DC solenoid that doesn't make the loud click when it opens like an Aprilaire. We've seen the fancy solenoids and circuit boards fail a few times, but we've got hundreds of them out there so it's not the worst.

If you have a basic forced air system with access to the supply and return ducts, a bypass will do the trick. The advantage is that it's the cheapest option and will work the same whether it's mounted on supply or return. The Honeywell units have a motorized damper that only allows air to bypass when calling for humidity, rather than a manual one that you have to open and close every season.

Fan powered units are fine if you have room on your supply duct. You can put them on the return, but they won't evaporate as much humidity with cool air traveling across the panel. In either case they work better when connected to hot water.

Any of the modern units have provisions for humidity on demand without a call for heat. My house in WI gets so dry that the humdifier can't keep up, so I set it up that way. The control will drive the fan on if the house is too dry and the furnace is not calling for heat. The downside is that they lose efficiency when the air is cool as mentioned above.

The biggest issue with the honeywell units is that the solenoid cycles on and off to save water, and because the unit is evaporating a larger percentage of the water that goes through it, they tend to allow more sediment to build up in the drains. Nu Calgon makes a cool in-line filter that will help. We install one on every unit and it's all but eliminated the issue.

You could definitely install it yourself, it's a pretty easy job if you have the tools. The modern stuff is pretty simple to wire, unless you're colorblind or suck at reading it would be hard to screw it up. We charge around $700 to install a Honeywell bypass unit, and about $800 for fan powered. The Aprilaire stuff is about $100 cheaper. We have to maintain pretty hefty margins on that stuff to make it worthwhile, so if you can DIY you'll save a bunch of cash.

 

checked the solenoid and it seems bad. Put 24V directly to it and nothing.

I also checked the leads and it never gets 24V. There is a relay that has a red light that also never goes on. It's a R1BU1C. There is 120V going to the relay from a humidifier spot on the Goodman board, and 19v on one end of the transformer, and then .19v on the other side. I did order the new transformer, and I guess I should get a solenoid. Should I also get a new relay too? Or I am so far down the rabbit hole, just to buy a new errythang.

 

Do you have an air proving switch on there that ties to the transformer?

 

great question. no answer really. just that the relay is hooked up to the transformer. Here are the pics that I have.

Another side question. I have a 2 stage furnace, but my Sensi thermostat doesn't seem to wired for one. There are a couple extra wires in the bunch, and one looks to have done something at some point, how can I test that is a wire for the 2nd stage. right now it does take a long time for the house to get up to temp.



on the right side, closest is the transformer, and next to it, the relay.

 

OK. so just made a discovery. I looked at the dip switches on the furnace and it's set for 1 stage instead of the two stages its capable of, so I set the thermostat to one stage. That problem solved, or is there a benefit of wiring it for two-stage?

The stray wire in the thermostat was for the humidifier power. Hence why no power to it. Then I tested a 26.4V wire and the humidifier powered right up, and with a 24V source, no power. Could I use that wire and just double it to the 26V source, which is the heat wire, or should I figure out why the 24V wire does not power up the relay/humidifier?

 

Goodman made a single stage/two stage convertible unit that had a two stage gas valve and control, but only a PSC blower without a two stage inducer motor or separate relay for a low stage blower speed. It's a horrible design because on low stage the exhaust gasses cool too much in the primary and condense. We see WAY too many heat exchanger failures on those units when they're set up as two stage. The wrinkle bends in the heat exchanger act as a sort of heat sink and the acidic condensation eats holes in them. Leave that thing set up as a single stage unit.

Your 500M humidifier is the most basic unit offered by Aprilaire. The only reason that RIB relay would be needed is if you're controlling humidity from your thermostat. I'm guessing you don't have a separate control for your humidifier either mounted on the wall or the return duct?

 

There's a switch mounted on the return duct, but it doesn't seem to be doing anything. It's flowing now when the heat is on as I've hooked the humidifier wire to the 24v heat wire at the thermostat.

Sent from a smatrphone

 

Does your thermostat have the capability to control humidity? I don’t see any other reason for that relay.

 

It's a Sensi thermostat, from what I see it doesn't. I do have a Honeywell one ,RTH9580, but i didn't install it and don't think it controls the humidifier either.

Sent from a smatrphone

 

I have the Aprilaire 600 and it only has manual humidity control. I think the 500 is the same. In any event the WERA bbs is amazing for its information stuff like this.

Ironically, racing, not so much.

 

I think there's a 500 and 500M and 600 and 600M where the M is manual only. Non M= Automatic.

 

So yeah....I just checked the humidity switch that's on the return, and uhhh it's not hooked up to anything Good reason why it doesn't stop anything when switched.

so how does the humidifier know when enough is enough then?