Smith boiler question

Simple question:

 Can I adjust the temperature at which my gas boiler kicks on? I'd like to lower it from where it currently is (presumably around 185 because I have baseboard heat) to around 170. I can't find any obvious control for this on my boiler.



Complicated explanation:

I just bought a house last March with a Smith GB100 gas boiler. I'm not sure how old it is, though it looks to be fairly new. The house also has an outdoor wood fired boiler that heats a garage with radiant floor heat and "supplements" the indoor heat: pex tubing from the wood burner runs into the "hot water tank" (not sure if that's the correct terminology here) located next to the boiler in the basement. The wood furnace also supplements a separate hot water tank for domestic hot water, but that is in a completely different loop.

The former homeowners told us that they kept the outdoor wood furnace water temp around 130 degrees. Talking to other people with outdoor wood "boilers", that seems low - I'm told that a 160 to 180 range is more common. Not only that, but a buddy of mine told me that baseboard heat is usually set around 180 to 185 degrees. If that's the case, then unless I keep the outdoor wood furnace hotter than the lowest temperature the water in the indoor boiler naturally hits between cycles, won't the wood burner actually pull heat from the gas boiler and cost me higher gas bills? The way I see it, without the wood burner in the loop, the indoor boiler will kick on to heat the house, then between cycles the temperature in the tank might fall to "x" degrees. When the thermostat in the house kicks the indoor boiler back on, it only has to heat the water back up to 185 from "x" degrees and maintain it there during the cycle until the house heats back up. But with the wood burner in the loop, that 185 degree water is flowing back outside into a furnace that's set for a lower temperature, and so the wood burner actually becomes a heat sink, doesn't it?



My goal is to keep the indoor gas from coming on as little as possible when I'm burning wood, so given the above, what I'd like to do is keep the wood burner around 170 degrees, and drop the temperature that the gas boiler kicks on to about the same. I read in the online literature that the current Smith G series kicks on the gas burners when the temp. falls 15 degrees below the cut out point for the burners. But can I adjust this setting on the gas boiler? I see no control that would allow me to adjust this.



Any help or advice here would be greatly appreciated. None of the heating companies around here want anything to do with servicing the outdoor boiler, and they don't seem to have any experience with this kind of set up. I do have a company coming out on Nov. 10 for standard maintenance of the gas boiler, but I'll be firing up the wood boiler this weekend, as the temperature here is expected to fall into the 30s. Thanks for your help.