Aprilaire Provides Humidity When You Need It

Did you know….Whole-house evaporative, or flow-through, humidifiers are designed to work in conjunction with your home’s heating system to provide controlled humidification throughout your entire home.  These humidifiers typically operate whenever your thermostat is calling for heat and your humidifier control indicates a need for humidification.  However, what if you live in a mild climate where there is not much call for heat, but your air is still dry?  You need a way for the humidifier to turn on your HVAC blower so you can be protected from all the ailments of dry air.

The Blower Activation Relay to the rescue
The Aprilaire Blower Activation Relay (part number 4851) is an easy to install device that enables you to turn on your HVAC blower on a call for humidity.  The installation of this device enables you to enjoy all the benefits of proper humidification regardless of a call for heat.  Your local Aprilaire dealer can install the Blower Activation Relay in a matter of minutes.  The only other requirement to get adequate capacity is to make sure the humidifier is plumbed to hot water. 

Call your Aprilaire dealer and schedule the installation of your whole-house humidifier today.  And if you’re concerned you do not get enough heating system run-time, ask about the Blower Activation Relay.  You’ll be glad you did.

Aprilaire – Protecting you from dry air, with or without heat, for over 50 years!


0 thoughts on “Aprilaire Provides Humidity When You Need It

  1. Sam Badalov

    Thank you for all of the information you are sharing. I have the Aprilaire humidifier, which works in conjunction with home’s heating system. It had been working for few years and recently a solenoid started to fail and would not ever shut the water off. It was detected that the Relay is bad and it was replaced. Under the normal configuration the humidifier’s solenoid should release the water whenever the HVAC ‘s blower starts. Well it does, while the humidity level is below the set value and then it interferes with the entire system . Here is what happening:
    1. Set the Humidifier to 35%. The unit is installed with a Manual Mode.
    2. Whenever HVAC air blower starts, I can hear the solenoid opens and water flows into the humidifier. The solenoid shuts the flow as soon as the blower stops. So far as it should be.
    Problem starts in a few hours (and my guess is whenever the humidity level reaches the set value):
    1. The HVAC furnace starts and I can see the gas burning inside the furnace for about a minute.
    2. Then I can hear a signal/attempt (to start) to the blower.
    3. This fails, the air blower does not start and then furnace stops too.
    4. Within 2 seconds it goes into the same cycle and this continues until (my guess again) the humidity level drops below the set value (35%). The HVAC thermostat upstairs always set to 68, but now shows 66. This supposed to start the heating cycle, sends the signal to HVAC, it fails to start blower and so on.
    5. I then turn off the Humidifier, power cycle the HVAC and everything back to normal.
    I tested this for few days now and results are consistent. No Humidifier – everything works fine. As soon as I turn it to 35% – within hours it does as described above. Any idea what could be wrong.
    Thank you.

  2. Rick Lambert

    From what I read, it says to hook up to hot water? Is this for all installations or just the fix when not getting enough humity using the blower activation relay. ?

    My solenoids fail after a couple years and will not flow. Appears there is a build up within the solenoid. Anything I can do to prevent this from happening. EXPENSIVE replacement for every couple years.

  3. Ben Kautz

    I have a model 350. When it was installed, was not aware of the huge water waste. The motor was very noisy from the start and sounded like it had a bad bearing. We paid over $900 to have it installed and can’t use it. Is there an Aprilaire model for hot water heating systems, that doesn’t use hot water and drain it?


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