Question about Aprilaire 550 Humidifier

Open Question

Check solenoid working - Aprilaire 550 Humidifier

Posted by Anonymous on


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Humdifier doesnt work. New solenoid valve two months ago. Water is not coming out of solenoid. Is it the transformer? Honeywell Humidifier.Model:

Check to see if there is 24 volts at the transformer when the blower motor kicks on, if not the transformer will need to be replaced. If you do have 24 volts then work you way from the transformer toward the solenoid and see where the voltage stops, could be the humidistat.

Dec 14, 2012 | Honeywell HE365 Humidifier

1 Answer

550 not working water supply is ok

Hello, check to see if you are getting 24 volts to the solenoid valve, if you are and it does not click on to let the water into the humidifier then the solenoid must be replaced. However if you are not getting 24 volts to the solenoid valve check if yuou are getting 24 volts at the transformer, if not then turn power off to transformer and check the continuity of the secondary side of the transfomer, you should have resistance if not replace the transformer. if that checks out good check the wire connection between transformer and solenoid and make sure it is tight. If wire connection looks good then either humidistat is bad or current sensing relay/sail switch.

Jan 30, 2011 | Aprilaire 550 Humidifier

1 Answer

Aprilaire 400 humidifier. No water flowing to the pad. I've checked the supply -- working. Replaced the solenoid, not working. Checked the electrical to he solenoid wnen system callilng for water -- no...

Check to see if you are getting 24 volts from the transformer, if not, turn off power to the transformer and check the resistance of the secondary side, if no resistance the transformer is bad and need to be replaced. Also check to make sure all the wires are secure. If you are getting voltage at the transformer then bring power directly from transformer directly to solenoid valve and it should click open and let the water through, if it does then either the sailswitch/current sensing relay is bad or humidistat is bad.

Jan 17, 2011 | Aprilaire 400 Humidifier

1 Answer

Aprilaire 550 There is no water going through the solenoid to the feed tube. I recently purched a new solenoid.

The first thing to check is if you are getting 24 volts at the transformer, if you are not then turn off power the transformer and check continuity. u should have continuity if not replace the transformer. If you are getting 24 volts at the transformer then apply 24 volts directly from transfomer to solenoid valve you should hear the solenoid cleck open and let the water in, if not then the solenoid is bad and must be replaced. If the solenoid does work by applying voltage directly to it then check the
wiring and make sure it;s all tight. Also check the humidistat and current sensing relay/sail switch to make sure it's functioning properly.

Jan 13, 2011 | Aprilaire 550 Humidifier

1 Answer

I installed a new Aprilaire 700 and everything looks normal except there isn't ant water flow, I am not sure if this is the solenoid or transformer problems?

Check if you are getting 24 volts at the transformer, if you are then appy power directly to the solenoid valve from transformer, you should here the solenoid valve click and let water through. If not replace the solenoid valve. If the valve works by giving power directly from transformer the check the wiring, humidistat, and current sensing relay/sail switch.

Jan 10, 2011 | Aprilaire 700 Humidifier

1 Answer

How do you check if the solenoid is working?

HI check there is power there or at the transformer

Dec 07, 2009 | Aprilaire 550 Humidifier

1 Answer

Have solenoid: MOPD 125, WATT 2.3, VOLT 24/60, for Aprilaire 560 Humidifier. With a M15 Universal tester using 150mA for + & K OHMS FOR -, I get 2 ohms on scale which would be approx 200 ohms. Ohms = Volts...

I am guessing you have sent 24 volts to the solenoid directly and the the solenoid did not activate?

If you have not send power directly

If the solenoid does not activate that way more then likely needs a new solenoid.

Mar 05, 2009 | Aprilaire 550 Humidifier

1 Answer

Solenoid won't open--voltage drops when connected to humidistat

The coil may shorting out the 24vac supply to the solenoid. Recommend replacing soleniod.
Normally you should be able to read the 24vac across the solenoid when energized.
The other option is to get a 120vac to 24vac transformer and test the solenoid. This way you will know if the solenoid is the cause or the 24vac source is the problem.

Feb 22, 2009 | Aprilaire 600 Humidifier

1 Answer

Aprilaire Model 560bone dry, water is on, what can I check?

Yes, just check to see if you have 24 volts going into the solenoid. If you do and it is not opening its probably bad. Since you verified the water lines, filter, orifice and saddle valves are not obstructed. Change the solenoid valve. When you price the part. (it's not cheap) consider paying about 30% more and just change the whole unit.
Good luk
HVAC Teacher

Feb 18, 2009 | Aprilaire 600 Humidifier

1 Answer

Solenoid on Aprilaire 600

solenoid valves dont just burn up just like that you have a recurring restriction due to bad water.Check the saddle valve at the water heater first then check for postive water flow at inlet to the solenoid valve,if you have water flow the valve is clogged with sediment.

Dec 13, 2008 | Aprilaire 600 Humidifier

Not finding what you are looking for?
Aprilaire 550 Humidifier Logo

Related Topics:

60 people viewed this question

Ask a Question

Usually answered in minutes!

Top Aprilaire Humidifiers Experts

Paul Carew

Level 3 Expert

2598 Answers


Level 3 Expert

744 Answers

Mack Baxter

Level 3 Expert

383 Answers

Are you an Aprilaire Humidifier Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides