hot water loop control question

AlexR

Our house is mostly steam heat but with a baseboard loop for one room.  There's a heat exchanger between the BB loop and the boiler.  There's a pump (call it A) on the BB loop and another (B) on the short loop from the boiler to heat exchanger.



In the current setup, the thermostat in the room with the BB turns on pump A.  An aquastat between the boiler and heat exchanger turns on pump B and the boiler.  Sometimes B doesn't run because the water in the pipe from the boiler to exchanger is hot enough even though A is running cool water through the baseboard.



Question: wouldn't it make more sense to have the thermostat turn on both pumps and let the the aquastat turn on just the boiler (rather than boiler and pump B)?  This way, hot water goes from the boiler to heat exchanger and through the BB loop.  When the water in the boiler cools enough, the aquastat turns the boiler on.



3

World Plumber

Pumps

It sounds logical. Makes sense to heat up the heat exchanger  when your trying to heat the baseboard. Be aware of your water temperature going out. If there is not a bypass to cool the water on the primary side you may need a limit aquastat  on it.