[allbrita]

Can lennox G26 24 vac hot terminal be used to power aprilaire 700 auto humidistat. Have only one 24vac transformer with Aprilaire 700 but Lennox HTG ACC is also line
(120vac) so required to convert to 24vac.

[hvac1000]

I try to never power any accessory directly off the furnace circuit board.

[allbrita]

Thanks... found that Aprilaire has 3 separate documents for install options on 700(A) model. Main template instruction sheet and new and improved install sheet do not show using heat call 24vac on the humidistat. Implies separate 24vac transformer needed if 120vac ACC or HUM. However the small yellow install book shows another option. So used 24vac transformer included for main power to humidistat and 24vac heat call (W) off G26 terminal strip to activate humidifier. Works great, but obviously only runs humidifier with heat call, but good enough to offset dry forced air.