Help with the heat!!!!!

[Thechap]

Okay, let me try to explain. I have a oil furnace hot water, with cast iron radiators. Last year I installed an OWB. I am using a heat exchanger which is in the basement next to the oil furnace. My problem is I have the oil furnace turned off. The thermostat is turned off, however the radiators are HOT! The circulator on the oil furnace is not on. The OWB is heating my domestic hot water. What is the problem? Is the heat exchanger heating my oil furnace water and it the rises? What gives? Please help!!

Bryan

 

[stee6043]

Sounds like perhaps you're getting a some thermosiphoning. A check valve on your oil furnace side may correct the issue. You may need something to prevent convective flows in your original oil furnace loops even if the pump is not running. If your OWB is still heating the HX you'll get flow even if the pump is off...

 

[deerefanatic]

Too much heat....... That's always a GOOD problem! Just think of that when it's -20F... LOL

 

[Gooserider]

Sounds like some sort of thermosiphoning or "ghost flow" problem, or possibly if you have everything shut off except for the DHW exchanger, you might be developing enough pressure to be pushing past your zone valves. As already suggested, you may need some additional check valves to prevent thermosiphoning. If it is a case of excessive pressure, you might need either a pressure bypass valve or one of the newer pumps that can reduce their outputs to match your load.

It would really help if you could post a diagram of your plumbing layout, even a rough one, as that will help us figure out where your problems are likely to be.

Gooserider