Recently when outside temp dropped to very cold my Burnham ES2 gas fired two zone, hot water baseboard heat failed to warm the house. One zone has been shut down by choice so i am dealing with one zone, one Taco cartride circulator, one circuit, relay et. Thinking my circ. Pump failed I took both pumps apart and switched cartridges. I tested both cartridges with a/c current and both operated ok. I switched relays on the circuit and tested for a/c at the pump connection and got120 volts when fired. My radiators are screaming hot, cant touch them without saying outch, but the house is never comfortable. At the boiler I noticed flame on for about 30 seconds then a couple of minutes flame off and then flame on for another 30 seconds. This cycle goes on and on. The thermostat, programable, is set for longer cycles rather than shorter and I have set the max temp at 95F but the temp never catches up beyond 60F or so and that after running an entire 12hrs. It seems the boiler is fighting a never ending battle. Insructions that came with the boiler suggest that in extremely cold conditions an adjustment should be made to the "High Limit Safety Control" but I do not know where it is or what it looks like. Quesions: Can my thermostat be the problem? Should I try adjusting the High Limit Control to a higher setting. if so where is it and what does it look like? Is there something else causing the problem - perhaps air in the line, although there is a bleeder device at the boiler that I was told woul eliminate the need to bleed each radiator.

Hi. First, here is my info: 1. In which area you live and ambient temperatures you usually experience. [B]CT (very cold in the winter)[/B] 2. House style and construction details. [B]2 story colonial[/B] 3. Make, model and age of equipment related to the problem. [B]Not sure, about 10 or 15 years old maybe? Maybe more, but I've been told it's in good condition, no problems, many years left[/B] 4. Fuel type. [B]Oil[/B] 5. Water temperature and pressures of boiler systems. [B]not sure[/B] 6. What type of zoning do you have with your boiler system. [B]two zones, one for upstairs and one for down[/B] 7. Thermostat type. [B]Nest[/B] 7. Anything else that would be useful. No detail is to small. The more information you provide the easier My issue is that I have very uneven heating, both upstairs and downstairs. I believe the heat travels through the baseboards counterclockwise, and the rooms it hits first (both upstairs and downstairs) are the rooms that get the hottest (almost unbearably/quickly) while the rest of the rooms get lukewarm at best. As an example, I keep the heat at 64 upstairs (where the bedrooms are) at night, as we like it cold and prefer to bundle up. When the temp drops to whatever level (62/63?) the heat comes on. The master bedroom (the first one in the loop) gets really hot/really fast (66/67), but the far bedrooms, where the kids are, barely get to 64 (which is perfect). Is this just the way it works or should it be more even? In the master bedroom you can really feel the heat if you are in the room. The other bedrooms you can really only feel it if you go over near the heater and put your hand near it. Same situation downstairs. Family room (first in loop) gets ridiculously hot really fast, while the rest of the downstairs barely warms up. Thanks for any thoughts!