Bock oil heater - needs constant air bleeding

Old 01-13-07, 01:25 PM
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Question Bock oil heater - needs constant air bleeding

We recently purchased an old farmhouse with a Bock oil heating system (water heater and furnace) which was installed new in 2000. The first month we occupied the property (Nov/Dec), the heating system seemed adequate. In the last two weeks, however, the system has become very problematic. Everything seemed to be working, including the hot water, but cold air was being blown through the heating vents.

According to the technician who visited, the reason cold air is coming out of our heating vents is because air rises in the pipes and stays in the attic where the air blowers are located. He showed us how to bleed the line of air, and that seemed to do the trick. After he bled air from the water line, hot air immediately began circulating through the heating vents.

However, the problem (cold air) is re-curring on an almost daily basis. We have become proficient at bleeding air out of the water lines, because we are doing this task almost every day, everytime the temperature drops inside the house and cold air begins to come out of the heating vents again.

Clearly, we have an on-going problem with too much air getting into the water lines. What can be done to resolve this?

Besides whatever issues may be connected to regular maintenance the system may require, two things are different now (i.e. different than from the first month of occupancy, when everything seemed to work consistently).

1) Towards the end of December we had a 5000 gallon storage tank installed (we are on a well). The storage tank has its own seperate line to fill it. The new line was run directly from the same well that services the house.

2) It is much colder now. For the past few weeks, temperatures have dropped below 20 degrees F, almost every night. The pipes leading from well into house are well protected, but the outside spigots (in the farm yard) cannot be used until early afternoon, after the sun warms things up.

Also, around New Years day, the Bock furnace ceased working, presumably because we allowed the fuel tank to get too low. It was off for two days while we awaited delivery of more fuel oil and a visit from the technician to get the system running again. Since then, we have had the problem with air in the lines. Prior to the system shutting down after New Year, we did not have this problem.

Advice for a long-term solution to prevent air from building in the pipes would be appreciated. Thank you,

Old 01-13-07, 03:21 PM
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Air in system

How much pressure is on the system? Some pictures of the boiler & near boiler piping would be helpful. You can post them on photobucket or similar site & provide a link here.
Old 01-13-07, 06:18 PM
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It sounds like a Bock water heater and duct coil. I would like to know if the heating loop is isolated from the domestic hot water or if they are all piped together. I don't expect you to know this but there may be some things that will be a constant problem if air is present in your water supply. The arrow on the circulator should point away from the water heater not toward it. An automatic air vent would be very helpful but probably not in the attic. There is too much potential for water damage up there. There are some piping practices that make a system like yours work better and if you can post a couple of pictures of the water heater and piping nearby, maybe we can help more.


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