I have a 20 y.o. Carrier FA4ANF air handler. Somewhere along the line the previous owners installed a GF 1040 bypass humidihier with a Honeywell H49A Humidistat The supply air mounted humidistat controls a 110V solenoid, which controls the water flow.
The problem is, 110V power is constantly supplied to the humidistat, so water flows even when the air handler fan isn't running. To avoid wasting all that water, I would like the solenoid to shut off the water when the air handler is dormant. The humidifier doesn't have a float valve.
Right now, the lead to the humidistat is wired to the Carrier's fan relay, to the SPT terminal on the board. I put my meter on it and it's always 110V.
What would be the cheapest/simplest way to control the humidifier? I guess I could purchase a sail switch for $50. If I went to all that trouble, I might as well pop for $100 and get a whole new unit.
Could I install a relay somewhere?
Advice?
Thanks!
The problem is, 110V power is constantly supplied to the humidistat, so water flows even when the air handler fan isn't running. To avoid wasting all that water, I would like the solenoid to shut off the water when the air handler is dormant. The humidifier doesn't have a float valve.
Right now, the lead to the humidistat is wired to the Carrier's fan relay, to the SPT terminal on the board. I put my meter on it and it's always 110V.
What would be the cheapest/simplest way to control the humidifier? I guess I could purchase a sail switch for $50. If I went to all that trouble, I might as well pop for $100 and get a whole new unit.
Could I install a relay somewhere?
Advice?
Thanks!