Our house had always had some latent heat coming through the vents even when they were turned off, which was causing the temperature to be pretty unbearable during the summer. One day, we heard something making a ton of noise in our garage, and we found the source was apparently a circulator pump, which we unplugged. After we did this, the heat from the vents disappeared, and it's been much cooler inside. However, the hot water no longer works with the pump off. Our landlord said he would replace the old pump, but we don't want the heat to come back. So my question:
Why is the circulator pump affecting the heating? From what I've read, it should just be pulling water out of the pipes, it's not clear to me why that would keep the heater hot all the time, even if it's heated by hot water.
Also, is there any way to have the circulator pump running but not heat the house at the same time? It sounds like the pump should save a lot of water, but we don't want to save water at the expense of the extra energy it's consuming and the heat it's putting out.