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Humidifier Not Filling Fast Enough

wirsbozo Member Posts: 15
I have an Aprilaire 800 whole house humidifier that I've only just started using. It's 8 years old, but I just moved in. After turning it on, it will go through the fill cycle but the fill light will turn red indicating "the cannister needs water but cannot fill." I cleaned the strainer at the valve inlet, and the cannister is new. Upon opening the humidifier up, the cannister is about 2/3 full with water. It seems that it is just not filling up sufficiently in the 40min required before the red light is triggered. The fill tube appears to be kinked, per picture below. After looking at a number of service videos for this model, it seems like the fill hoses all look this way, but I'm assuming this is what's causing the problem. I assume replacing with any sturdy hose of the right diameter should be fine? Am I looking in the right direction for the problem? Thanks!


  • Larry Weingarten
    Larry Weingarten Member Posts: 2,544
    Hi, I’m stepping out on a limb as this is not my field, but if you turned off the water supply and then disconnected the fill tube at the bottom end then run it to a bucket… See if you can get flow with the tube bent as it is. Maybe there is debris in the line, or it’s crimped. A completely different idea is to put a small hose clamp around the crimped area to see if it opens up enough.

    Yours, Larry
    HVACNUT Member Posts: 4,590
    edited January 23
    Is the reservoir where the can sits clean? When canisters get nasty then dry out they can drop debris and clog up the inlet.

    Is it draining while filling? Remove the 4 screws for the steam pipe at the duct and inspect the discharge tube.
    Now try filling while the discharge is out of the duct. The manual says too high static pressure will also cause your issue. 
  • wirsbozo
    wirsbozo Member Posts: 15
    Thanks, Larry and HVACNUT. I'll check the water line itself. I like the idea of a hose clamp to open up the crimped area before finding and cutting a new line.

    It is not draining while filling, but I did see it go through the cycle where the fill and drain valve pulsate to "dislodge mineral buildup in canister." Will try filling while the discharge tube is out, as well. Thanks!

  • wirsbozo
    wirsbozo Member Posts: 15
    Figured it out. Took all the lines off and examined them. There is a flow restricting coupling on the line after the electronic water inlet valve. The internal diameter is so small that it does not take much to clog it up. After cleaning it the canister fills up in time with no issues.

    Now that this is fixed and observing it operating for a bit over a week, it's clear that the 11A 120V setting on the humidifier is inadequate for efficiently humidifying my house, which is a bit over 5k square feet. It runs 24/7 and seems to keep the house around 25-30% humidity (better than the 18% it was hovering at before). It's on a dedicated circuit - 120v w/ a 15A breaker. Not sure why the previous owner had it wired that way, but I'm going to want to put it on a 240 circuit next season. My trouble is I'm not too knowledgeable on electrics and wondering how involved it might be to have someone change to a 240 circuit.
  • Jamie Hall
    Jamie Hall Member Posts: 18,907
    That depends (the change to 240 volts) on two things: exactly how the electrical code is enforced in your area, and whether or not the appliance being served needs a neutral. In many codes, and certainly if a neutral is needed, you are going to have to run a new cable with four wires: red, black, white, and green or bare. That will go all the way back to your switch box, and the switch box will have to have a new circuit breaker for the 240 volt service; there may or may not be space for that.

    The other rather obvious question is whether the Aprilaire can be used with 240 volts, and whether anything will be gained by doing that. Ah. I have the manual. Yes it can be, but it appears that setting the operating voltage and current is part of the installation process; I doubt that it is a diy project.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • wirsbozo
    wirsbozo Member Posts: 15
    Thanks, Jamie. Yes, on the unit itself, it seems to be a matter of moving the dip switch to 16A and moving the jumper wire to 240 vice 120. You mention a couple hurdles I'm seeing --- space on my switch box being the first one -- there appears to be only one unused slot at the bottom, and it's a single pole. I'll have to take another look at the manual for the unit to see if it requires a neutral.

    Seems like a lot to gain with using 240, per the manual, especially since my water is not too hard (cheap test strips seem to show it at 7-14 gpg unsoftened.

  • mattmia2
    mattmia2 Member Posts: 5,506
    If one breaker is unused the breakers could be rearranged and a double pole breaker could replace the single pole that feeds it now. unless the nec changed recently there is nothing wrong with reidentifying the neutral as a second hot for a 240v only appliance in a 2 conductor w ground cable. You could potentially free up space with tandem breakers but I think residential panelboards are limited to 40 poles.
  • Mosherd1
    Mosherd1 Member Posts: 34
    @wirsbozo, I’m an electrician and have a question for you on your unit; I haven’t looked at the literature for it. Typically if we hook something up at 240 volts it uses 1/2 the amperage that it would if it is hooked up at 120 volt, but the wattage stays the same. The power formula is VOLTS X AMPS=WATTS. Watts is what is actually heating the water, if the output wattage of the unit doesn’t change with the voltage change, you won’t get anymore humidification output; however some set-ups ie. hot tubs do change the wattage output when you change the voltage, but most things like well pumps and such don’t.
  • mattmia2
    mattmia2 Member Posts: 5,506
    It is a resistive load, not a motor load. The power increases exponentially with an increase in voltage although I think in that particular device it has a controller that limits the power to what the circuit can provide.