AIR TUBE

detmurds said:

After using my fireplace for 100% of the heating last year, my Avolon "Pendelton" air tube warped. No I did not burn any building lumber, and 99% of the time I burned Douglas Fur,....now, the dealer gave me a new air tube free of cost, ...but I am still puzzled as to why it did what it did. I am guessing I burned too hot with the damper open for the first part of the winter,..is this a good excuse?

I replaced the air tube, and the chimney gets swept and inspected on 7 Sept.

Click to expand...

Sounds about right on the cause... Remember that softwoods like fir tend to burn hotter than the typical hardwoods, even though they don't burn as long. Thus it is probably easier to over-fire while burning softwoods, leading to damage of this sort. (Note that you might not want to say this to the dealer - remember that overfiring voids warrantees...)

Gooserider

Yeah, to me it sounds like you're allowing the open damper burn at the beginning of a new load to last a little too long. I've done the same thing and seen my tubes glowing red for a while, but I used much thick stainless than necessary so no warping took place. Just cut that wide open time down and step down, instead of remaining at wide open the whole time. In other words, leave it wide open for a new fuel load maybe 5 minutes, then step it to 3/4 open for five and then half for five and then put it back to the desired heat output level. That's just an example, of course things will vary for you, but you get the idea.

Burning mostly fir and soft maple last year, I could leave the air open full for only a few minutes and then I'd have to adjust the air down to the "sweet spot". A few times my wife loaded it up and let it rip simply because she forgot about it. I'd come home and see this ball of flame (in the stove) from the drive way...I couldn't get into the house fast enough!