Aprilaire 550
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Aprilaire 550
My Aprilaire stopped working some time over the last couple of months. I replaced the solenoid valve and humidistat and it still doesn't work. In fact, I replaced the new solenoid valve with another one because I was so convinced that was the problem. It doesn't seem to be. If i remove the humudistat from the circuit and connect the two wires together this doesn't open the solenoid valve. Any suggestions would be much appreciated, I'm completely stuck.
I should add there's no problem with the water supply to the solenoid. The solenoid doesn't make any noise and does not allow water to pass through. Thanks.
I should add there's no problem with the water supply to the solenoid. The solenoid doesn't make any noise and does not allow water to pass through. Thanks.
Last edited by Legolizard; 02-03-17 at 08:48 PM. Reason: Add more info
#2
Welcome to the forums.
I'm guessing you have the two wire manual humidistat. Basically it's just a switch so if you short the two wires together and nothing happens... you don't have your switched 24vac source.
When you shorted the two wires... the furnace should have been in heating mode.
You'll need to follow the wiring back into the furnace to see where it connects.
I'm guessing you have the two wire manual humidistat. Basically it's just a switch so if you short the two wires together and nothing happens... you don't have your switched 24vac source.
When you shorted the two wires... the furnace should have been in heating mode.
You'll need to follow the wiring back into the furnace to see where it connects.
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Thanks for your help. You assumed correctly about the humidistat. I removed it from the circuit and tied the cables together. Then I made sure the furnace and fan were running and checked the DCV going to the solenoid and it read 0V. As far as i can tell from the wiring the only thing I haven't accounted for so far is the furnace part of the circuit. Is there a control switch on the control board of the furnace that only gives power to the humidifier when the fan is running? The furnace is only a year old so I never thought that could be an issue. Thanks again.
Last edited by Legolizard; 02-04-17 at 09:34 AM. Reason: Fix typos
#4
The voltage we're working with is AC.... 24v.
Usually the control board is on the lower section where the blower is.
Remove the door and see if you can locate it.
Usually the control board is on the lower section where the blower is.
Remove the door and see if you can locate it.
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Damn it. I opened both doors to the furnace and it looks like the wires for the solenoid valve are not connected to anything, just tucked in the back. I can't believe the installers just didn't hook it up. I guess i'm going to have to try and work out where the humidistat cables end up. Thanks and sorry for wasting your time.
Last edited by Legolizard; 02-04-17 at 09:50 AM. Reason: Fix typo
#7
No problem !
Post a picture of the control board or the part number on it.
The make and model of the furnace would also be helpful.
I'll help you get it connected.
Post a picture of the control board or the part number on it.
The make and model of the furnace would also be helpful.
I'll help you get it connected.
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Hi,
I attached two pictures. One of the board and one zoomed in the region I think is where the wires should go. Also, I don't think the wires will reach. Do I need anything special. I have some left over cable from when I replaced a light - would that be OK?
http://imageshack.com/a/img924/7094/Zi2vcJ.jpg
http://imageshack.com/a/img923/6007/iFzMyC.jpg
I attached two pictures. One of the board and one zoomed in the region I think is where the wires should go. Also, I don't think the wires will reach. Do I need anything special. I have some left over cable from when I replaced a light - would that be OK?
http://imageshack.com/a/img924/7094/Zi2vcJ.jpg
http://imageshack.com/a/img923/6007/iFzMyC.jpg
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Pete, thanks again for your time. I was able to get the original furnace installers to come and wire the solenoid in. Glad I found this site! It's going to be a great reference point.