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[mgw44]

Quick question:

I installed my indoor thermostat for the boiler to run the furnace fan.  Does anybody have any guidance to hook up the furnace humidifier to the indoor boiler thermostat so that when the fan runs the humidifier runs also?  Can I just run 24V 2 wire from the humidifier up to the thermostat and piggyback it onto the same G and hot that I put my fan into?

Thanks,

mgw44

[dumbodog00]

Good question because mine only comes on when I burn propane....which is almost never.

[tulenutn2o]

Quick question:

I installed my indoor thermostat for the boiler to run the furnace fan.  Does anybody have any guidance to hook up the furnace humidifier to the indoor boiler thermostat so that when the fan runs the humidifier runs also?  Can I just run 24V 2 wire from the humidifier up to the thermostat and piggyback it onto the same G and hot that I put my fan into?

Thanks,

mgw44

Short answer, Yes.

[R W Ohio]

I would use a #50 relay from an April Air Humidifier. It clamps around the common wire to the furnace blower motor and it's contacts close when it sees motor current. Use a small transformer, 10 va that comes with most humidifiers, make the transformer hot all the time run power from the transformer to one side of the #50 relay then to the humidistat then to the humidifier and back to the other side of the transformer. On a call for humidity from the humidistat, if the fan motor is running the power will be supplyed to the humidifier.If the fan motor is not running and the humidistat call for humidity no power will be sent to the humidifier.

If your humidifier is line voltage use a #51 relay and do the same as with the low voltage unit, you just won't have the 24volt transformer to deal with.

[mgw44]

Thank you for the replies.  I tried my original idea and it failed.  The furnace and water would turn on but then it would not turn off.

RW I appreciate the response very much but you lost me at transformer.  Unfortunately, I am not that smart.  The concept sounds great but I am not confident that I could install that system.

I noticed my AC unit coming on when the fan turns on.  So, I pulled the breaker on the A/C.  How about I disconnect the A/C from the Y and C terminal on the furnace and connect the humidistat/humidifier to the Y and C terminal?  I would have to mess with it Spring and Fall but I have to do so many other things to the boiler anyway this is a minor inconvenience to switch between the humidifier and the A/C unit.

mgw44

[F7JC]

Thank you for the replies.  I tried my original idea and it failed.  The furnace and water would turn on but then it would not turn off.

RW I appreciate the response very much but you lost me at transformer.  Unfortunately, I am not that smart.  The concept sounds great but I am not confident that I could install that system.

I noticed my AC unit coming on when the fan turns on.  So, I pulled the breaker on the A/C.  How about I disconnect the A/C from the Y and C terminal on the furnace and connect the humidistat/humidifier to the Y and C terminal?  I would have to mess with it Spring and Fall but I have to do so many other things to the boiler anyway this is a minor inconvenience to switch between the humidifier and the A/C unit.

mgw44

Let me know if connecting it to the y and c worked... thanks

[mgw44]

this seemed to work well.  I wired straight up the the humidifier and bypassed the humidistat.  Our house is really dry.  So far the setup is working well.  If it gets too humid in the house I will hookup the humidistat.  I've checked the humidifier a few times and water is being supplied when the fan is running.  The water is not running when the fan is off.  I would consider that a success.  If I have any problems in the future I will post an additional reply.

mgw44