Actually I do not use a fan initially when firing the boiler. The natural convection through the vertical flue is sufficient to raise steam, although a fan would no doubt speed up the process.
I did find that I needed to shorten the stack above the boiler, however, to get sufficient convection flow through the flue. With the original length stack one could hold one's palm a few inches above the stack and not feel any discomfort from the heat. After the stack was shortened this was no longer possible and steam was raised quicker.
My theory is that without forced draft the flue gas flow stalled in the longer stack. Of course with a blower the stack length would be a lot less critical. When I do fit the permanent blower I will try to tailor the stack length according to the final vertical position of the blower nozzle in order to maximize the blower's effect.
Steve
[EMAIL PROTECTED] wrote:
I assume you used a fan initially.
