Cycle Length Sweet Spot

superMARKet

I finally got a vaportstat. After two PA404s, I'm amazed at the degree of control. Most importantly, I was able to crank the pressure down. The water hammer's nearly gone, and I'm probably consuming less fuel.

I'm wondering about cycle length, though. Right now, I'm seeing 10-12 minutes on, 2 minutes off. Noel mentioned something about the "sweet spot," but I'm not sure if I'm there yet. 2 minutes seems too short to me, but the pressure drops steadily in the off phase.

I'm set up for 1.25 pounds - 12 ounces. I got hammer at 1.5 - 16, so I kept the half-pound cut-in and dropped the cut-out until my radiators and pipes shut up. (The oil guy set it to 1.5 - 8, but the oil guy sells oil and doesn't have to listen to the banging.)

So is the off phase too short, or am I near my sweet spot? I was thinking that a too-short off phase could be a venting problem.

Mark