puzzler

Frank_7

This is kind of long and involved and I am not too conversant in this area but since the tech I have working on it appears to be stumped I'm looking for any crumb so it's worth a shop.

To start we moved into a 30 year old home about 18 months ago. The heating sytem is a three zone tube and fin hot water system and the boiler had been replaced in 1997. The boiler chosen was a Lennox oil fired model "Conservator" (made by Dunkirk Radiator) with a Beckett burner system.

We got the first cleaning when we moved in and (now) it appears that the service person I got mis-read the settings on end cone, due to the boiler unit it was changed out to a smaller end cone. Naturally enough it clicked off in about a few days time and another service tech came out to service the unit. He claimed that the unit was burning too clean and did something that at least allowed the unit to operatte for about a year with no problems (though I did seem to be burning a lot of oil.)

Come next October (2002) the boiler was clicking off and I punched the reset. I called for a service and a cleaning. The service resulted in the replacement of the fuel pump (I have an overhead line). I was told that it wasn't pulling suffieciently. The boiler continued to click off and I called again. This time the tech, a new one, seem genuinely puzzled by the operation of the burner, doing a million different things and then calling in the original tech. Seems that they weren't using the right settings on the end cone.

They fixed that and things were ok for about a month and now the damn thing is clicking off again. It only occurs at night when I shut the other zones down and leave the top floor zone on. When I reset it fires right up so I called again and this time the tech didn't seem to know what to do. It clicked off the in two days and this time there appears to be some leaking at the overflow valve.

Can anybody give me a hint at what is going on? The tech appears to be stumped, its the middle of winter and I need some guidance.

Tom M.

Oil-fired

A few thoughts: If they are replacing the oil filter every time, there could be air getting trapped in the overhead line. To properly bleed, valve at tank should be closed once flow is established to increase vacuum on line and draw absorbed air out of filter material. Then open valve and continue to bleed. Another shot of air will make its way out in a few seconds depending on the length of the line. If this is not done, the air will come out of the filter over the next few days and get trapped in the overhead line. There should also be no connections in the line above the height of the oil in the tank. You said it happens at night. Is the tank or line exposed to freezing temps. The fact that you pressed the reset and it operated normally is enough info to justify installing an Onwatch Burner Monitor. This can diagnose pressure/vacuum problems in the oil system as well as a dead spot in the motor, a slipping drive coupling, problems in the ignition circuit, cadcell circuit, any intermittent problem with voltage or controls. Based on the information given, any of these could apply.
Tom M.