Aprilaire Model 600 doesnt work

[hockeybc69]

I contacted Aprilaire to see if they could give me any ideas and they said to have an HVAC guy come out to look at it....

When I turn the dial to about half way, it turns on the water and it never shuts off.

If I turn it down to make it turn off, it never engages at all.

So its either full on or full off. Full on isnt any good, I just have water running into the drain constantly.

Any HVAC guys out there with any simple tips on what to try or what it might be?

Thanks

PS - the house is DRYYYYY. Sleeping sux. I have a small humidifier upstairs that I turn on in the evenings, but thats not doing much of anything.

[Tom7227]

I am not a HVAC guy but I have one of these things. I think it is either on or off. It is on if the device on the wall is set above the ambient humidity in your home. You need to buy a hygrometer - the device that gives you the humidity reading in your home. The setting on the device on the wall is supposed to be changed based on the outside temp,at least on the one I have.

Your problem may be that the foil type filter inside the aprilaire is all full of calcium and gunk. Have you ever changed it? If not make sure you know what model you have and go and buy a new one and put it in. It is a PITA to figure out so you may even want to measure your old one, or even take it along. If you do find a replacement keep the tag on the box that gives you the part number.

[bgmny]

A call for heat from your thermostat will enable the humidifier to come on if the humidistat is calling. If you run your fan on your furnace all the time it would let the humidifier run if it needed to. If the humidifier comes on without the furnace fan running you have a controls issue. You should hear some sort of a click sound when you turn the H-stat up and down. If that doesn't turn it off and on by itself it could be bad. The H-stat basically opens and closes a valve that lets water go to your humidifier, pretty simple concept. The valve might also be stuck open?

[Jarred]

From what I read on that model there will always be water flow if there is a call to help wash away minerals down drain. I work in the HVAC field. Once done calling valve should close. Hope this helps.

[hockeybc69]

I do hear the click sound when I turn up the dial. Water immediately turns on, and never shuts off until I turn the dial down again.

The filter is kinda dirty with mineral deposits.

How does that simple control know the filter may be dirty? Interesting.

I surely can try that first.

[Dave]

I have model 560. Theres no way, on mine, that any control is going to know if the filter's dirty. Turning the control up untils it clicks should not turn on the water. When the blower fan is running, the current it picked up by a sensor clamped to the wire on the blower. That is what opens the valve for water flow. The valve is probably stuck open.

Thinking about this a bit more, sounds like the valve does open and close so, check the sensor.

[Tom7227]

It doesn't know when the filter is dirty but the filter may not be allowing enough air to flow through it to actually evaporate any water and send it through the house.

I have a two speed motor on my furnace. It stays at a low speed as long as I have it set on "fan". The humidifier should not turn on when at that speed. When the furnace is on to give heat the fan kicks up to a higher speed and that's when the water should start to flow. If it has worked that way before there's a good chance there's nothing wrong with the controls or the electronic. I'm betting that the filter jobberdo is just all gobbed up and not enough air is getting through it to evaporate enough water.

When you are at the store to buy the new filter get a hygrometer - the jobberdo that shows you the relative humidity in the house. That way you can tell how much there is and get an idea how things are working. The hygrometer is most often sold as a set along with a temp gauge, probably cost less than $15 for the set.

[Dave]

Maybe I'm reading the OP wrong. Sounds like even without the blower on, the water is running. That shouldn't have anything to do with evaporation and excess water.

[hockeybc69]

Thats correct Dave.

[Dave]

Any service work (change) been done lately to the setup? I don't know why the humidistat would cause the water to run and shut off. The current sensor is supposed to do that when the blower is running.

[FM_Mike]

I had the same problem on the Aprilaire 560. I ended up changing the water valve on the unit. It was so filled with calcium on the inside that the plunger in the valve would either stick open, closed, or any where in between.

Got the replacement valve on Amazon, a lot cheaper than dealers, put it on AND changed the mesh filter and everything works properly now.

As someone else mentioned, it is important to change those filters at least on a yearly basis. Some say every 3 months.

When working properly, you can really tell the difference in the house, and if you happen to have wood floors, it is a must it works properly top avoid damage to the wood.

Mike