It’s difficult not to be pleased to see the fireplace boiler working as planned in its new surround. The wood fire exudes such peace and tranquility on a snowy winter evening and adds heat to the radiant system. Directing heat to the water and radiant system means the fireplace does not overheat the room. The outside air piped into the stove means that the room does not get drafty as air rushes in to replace the oxygen used by the fire.
Turning on the system switch starts the primary pump, sending water through the stove, preparing the stove to have a fire started. As the fire heats up the circulating water the aquastat turns on the secondary pump sending hot water to the heat exchanger in the utility room.
In order to use the heat, the main heating system pumps must be running. I have to create a call for heat by raising the temperature in the rear of the house which opens that zone.
The call for heat turns on the boiler system and its secondary pump.
The boiler receives warmed water from the heat exchanger which turns off the gas heat because it believes the water is at heating temperature.
The stove heats up the circulating water. I can move the TV out of the way to see the pressure and temperature gauge.
The red indicator is set to 15 lbs pressure which is about atmospheric pressure. The stove is designed to heat at that pressure and the safety pressure relief will pop off at 30 psi which is also atmospheric pressure. The gauge is reading below the red indicator at 13 lbs.
The temperature dial is under the pressure reading. It reads 110 degrees. That warm water will cool in the heat exchanger sending warmed water to the boiler. The boiler modulates it’s firing due to the warmed return water, even turning off depending on the outside temperature. The design temperature for the radiant heating system is 87 degrees. That means that if the temperature in the pipes is 87 degrees it is warm enough to heat the house down to an outside temperature of zero.
The stove is only capable of about 26000 btu so it’s appropriate to send the warm water to only one zone. Since it is also ultra high efficiency and emits very few particulates this contribution to a snowy afternoon and evening is a thing of beauty.