[KISS]

Why did you make me work so hard?

This should explain things:

http://www.transtaracsupply.com/pdf/sv95control.pdf

It's the gas valve. See page 5.

Note the fans have to be controlled by a t-stat too. I did not look closely on how the "to fan timer" works on the valve.

But the wall switch turns the fireplace on and off. The outlet is just a convience outlet. They want you to use a 120 V stat to control them.

Note there is a suggested safety in the valve diagram. A high limit control.

It almost looks like you could do a lot better by using a thermostat and wiring things such that the fan comes on with decreasing temperature and the on/off control on the t-stat controls the fireplace.

The wiring and the selection of a suitable thermostat would get tricky, but not impossible.

Most t-stats don't tell you exactly what happens in say a HP thermostat. There would be a reversing valve and a call for heat.

The tstat could operate in the following way: a) The mode selects the state of the reversing valve independently of a or call for heat.

b) When off, the reverseing valve is OFF independent of the actual heat or cool mode. When in heat mode it is on.

If it's (a), then the fireplace gas valve could be controlled by the reversing valve and the fan controlled by the "call for heat" terminal. Off turns the gas and fan off. Mode (b) would save energy.

Both modes would control a Heat Pump (HP), but not a fireplace.

You would need a 24V relay to switch the 120 V to operate the fans too.

Yea, the fireplace diagram looks confusing because it tells you nothing about the operation.

Usually a furnace contains a 24 VAC transformer. You would think that this kit would contain one.

[KISS]

<Moved to HVAC>

after a move from Interior home improvement to Electrical and Lighting while I was answering the question. Grrr.