Hi, I'm new to this forum. A couple years ago we installed an outdoor wood furnace and tied it into our oil fired boiler . We have a heat exchanger between the OWF and oil furnace. We use the oil fired boiler as a back up to the OWF. The problem we have is excessive water coming from the base of the oil fired boiler . It does not produce water all the time . Sometimes it is dry around the base of the oil furnace and sometimes it is wet. Sometimes when heating with the oil furnace there is no water , sometimes when the OWF is on there is water and sometimes no water. The oil furnace technician said we have excessive condensation but for some reason could not explain it. There is no change in water pressure gauge so we don't think the boiler has a leak. We do not use either furnace from april to october and during this time there is no water around the base of the oil furnace. Any insight , assistance appreciated .