I saw an hydronic heating system in a trade show last winter. The system has a tankless hot water box, a heating box, a pump control box with an a couple of external pumps and a hydronic heating unit. I am planning to install hydronic heating in my house. I want to understand how these components work together. Here is what I learned from reading the trade show materials. Please correct me if any of my understanding is wrong.
1. The tankless hot water box provides hot water to heat up the house. It turns on automatically when there is a demand for hot water. It heats up city water.
2. The heating box distributes heated water from the tankless hot water box. It has a build in pump. It is controlled by thermostat. When the thermostat calls for heat, it will turn on the pump which creates the demand for hot water. This demand will turn on the tankless water heater.
3. The pump control is a supplement to the pump of the heating box. it will turn on the external pumps if the hot water distribution circuit is larger than what the internal pump of the heating box can handle. It is controlled by thermostat.
4. The hydronic heating unit provides heat to heat up the space. It is controlled by thermostat. The thermostat can be on the wall or in the floor (if it is a floor heating system) or both. It will call for hot water when the thermostat calls for heat.
If my understanding is correct so far, then my main question is where should my thermostat be connected to? I now have 3 boxes (the heating box, the pump control and the hydronic heating unit) that can be controlled by the thermostats.
My first answer is to connect my wall thermostat to the hydronic heating unit. This will cause the unit to call for hot water when the room temperature is below my settings. But the water will not come unless I turn on the heating box and the external pump. How do these components normally work together?
1. The tankless hot water box provides hot water to heat up the house. It turns on automatically when there is a demand for hot water. It heats up city water.
2. The heating box distributes heated water from the tankless hot water box. It has a build in pump. It is controlled by thermostat. When the thermostat calls for heat, it will turn on the pump which creates the demand for hot water. This demand will turn on the tankless water heater.
3. The pump control is a supplement to the pump of the heating box. it will turn on the external pumps if the hot water distribution circuit is larger than what the internal pump of the heating box can handle. It is controlled by thermostat.
4. The hydronic heating unit provides heat to heat up the space. It is controlled by thermostat. The thermostat can be on the wall or in the floor (if it is a floor heating system) or both. It will call for hot water when the thermostat calls for heat.
If my understanding is correct so far, then my main question is where should my thermostat be connected to? I now have 3 boxes (the heating box, the pump control and the hydronic heating unit) that can be controlled by the thermostats.
My first answer is to connect my wall thermostat to the hydronic heating unit. This will cause the unit to call for hot water when the room temperature is below my settings. But the water will not come unless I turn on the heating box and the external pump. How do these components normally work together?