Go Back  DoItYourself.com Community Forums > Heating, Cooling, Air Conditioning, Ventilation and T-Stat Controls > Humidifiers and Dehumidifiers
Reload this Page >

Solenoid has 24v, but fails to stay open with Aprilaire 600 / Model 50 relay

Solenoid has 24v, but fails to stay open with Aprilaire 600 / Model 50 relay

Reply

  #1  
Old 01-06-17, 05:09 AM
M
Member
Thread Starter
Join Date: Jan 2017
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Question Solenoid has 24v, but fails to stay open with Aprilaire 600 / Model 50 relay

I have an Aprilaire 600 humidifier system tied into my heating system that is not working. When it should activate, I hear a clunk coming from the solenoid valve and see a very brief spurt of water, but not the consistent feed that I believe I should see.

I had a pro come out and he told me the solenoid valve had failed, even though I showed him the fact that a little water comes out when activated.

So I purchased a new valve and installed in. And nothing has changed, which, to me, means that the original was fine and the problem is elsewhere. So after reading other threads and comments from PJMax, I poked around a bit to investigate.

For starters, when the system is activated and I hear the solenoid, I have 24v running to it (actually 27v). Yet it doesn't stay open.

When I bypass the Model 50 current sensing relay, the solenoid stays open and water flows.

But I don't understand why it doesn't work with the Model 50 relay because I see only slightly less voltage when it is in use. The relay appears to work. I see about 26.5v when the blower is powered, and about 7v when it isn't.

Is the relay malfunctioning and limiting the amount of current getting to the solenoid, preventing it from staying open?

Is the humidistat at fault in not providing enough current in the first place?

Have demons beset my HVAC system with the goal of ensuring that my family has dry skin?

I don't know. But I'd certainly appreciate any insight others could offer. Since I don't know the model of the humidistat, here is a photo of it (turned off). This shows the relay being bypassed, and you can also see the outdoor temperature sensor wired in on the far right terminals:

Name:  IMG_20170105_210151.jpg
Views: 644
Size:  35.8 KB

Thanks for any help.
 
Sponsored Links
  #2  
Old 01-06-17, 09:46 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,099
Received 1,112 Votes on 1,032 Posts
Welcome to the forums.

It certainly sounds like a defective 50 control but usually when that is the problem.... the voltage at the solenoid is very low. Yes... the 50 can reduce current flow but if it does... the voltage also goes down.

Try this.... instead of just running a single wire thru the 50's loop..... run that same wire thru again so that the same wire goes thru the sensor twice. That may help the sensor to fully turn on.
 
  #3  
Old 01-08-17, 04:41 AM
M
Member
Thread Starter
Join Date: Jan 2017
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Okay, I'll see if I can manage that. There's no real slack in the common wire, though, so it might not be possible.

Originally the 50 was just taped next to the entire bundle of wires coming out of the blower motor without the common specifically going under the metal clip, and that had worked for over a decade.

Thanks much.
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: