on my system (oil heat/tankless hot water), the demand (thermostat) kicks the pumps on/off - subject to min. temp being met. flame is governed by the water temp. But I'm not a pro...
: I live in Canada, close to Niagara Falls, and am trying to understand the hot water heating system in a house that I just purchased. It is not getting the house warm enough.
: It is from the 1950's, but the oil hot water system was upgraded in 1991 with a gas conversion package being installed on the boiler (an old cast iron system).
: The piping is (all copper) 1 1/2 inch loop, with the radiators in parallel to the loop, which does not make sense to me, since I am used to radiators being in parallel to each other with a supply and return line at either end. (even the radiators being in series sounds better than a loop with radiators feeding off the loop)
: Also, the filling station is straight off the cold water line, with a turn valve, check valve, pressure relief valve, ball valve and pressure gage in series, connected to the return line, open constantly and draining (dripping) constantly. The pressure goes from about 15 at rest to 32 psi during running conditions, at which time the system drains in a trickle.
: Lastly, the boiler controls are temp. sensors on the return line ( on top of the boiler) for the max. water temp set to about 150-160F, and the pump on/off switch set at about 120F. and the wall thermostat controlling the boiler flame unit.
: Am I correct in assuming the demand should switch on the flame, and the rising water temp should kick in the pump at the min. temp. till there is no demand, the flame stops and the pump kicks off when the water temp goes low? (and the heater stays off till the water temp drops below 150F)
: Off course with the water going in a loop, the water temp will go high fast, but not enough heat will go to the radiators.
: Could you let me know if my thoughts are correct, and I should be putting another return line next to the supply line, and rerun all the radiator returns to the return line, or could I just put a restriction in the feed line between all supply and return points for each radiator and thereby force more water through the radiators. (this I assume would not be the best way, but surely the easiest way.