My ARFCOM-infamous home heating oil furnace once again has an issue. We have forced hot water heat and our shower/sink water is heated by the furnace via some kind of internal coil system.

I opened the oil filter housing (located where the fuel enters the house, near the furnace) to check the filter condition when I had a problem a couple weeks ago. It looked fine so I didn’t replace any parts.

Since then it’s been leaking onto the floor at the rate of perhaps 6 to 8 ounces a day. That doesn’t sound like much, but it’s enough to drive my wife crazy with the smell.

Today I had the time to troubleshoot. I cleaned the filter housing well and then turned on hot water to cause a demand on the furnace. I observed the leak to be from the bottom of the bolt on top of the filter housing, which my online research shows being called the “filter mounting bolt.” I went to the hardware store and purchased a filter replacement kit which included the gasket for that bolt. I came home, shut off the furnace, opened the filter, replaced the gasket, and turned the furnace back on. It appears there is still a tiny leak, though much less than before. I tightened the bolt more and it didn’t seem to make a difference. I’m leaving it for now with an absorbent pad underneath to see what happens. Could it be perfectly fine and the leak I see is actually just residual oil from my opening the bolt? Could it still be leaking? The gasket looked substantial and not too thin so I’d imagine it is sealed quite nicely.

Thank you.

Ok, it’s been about 28 hours. There’s evidently still a tiny leak that has made its way down to the absorbent pad that I placed below the filter. It’s not even enough to smell unless you’re standing right above it.

For what it’s worth, the filter housing has only part of a paper label left and it’s not legible anymore. So I’m not sure the exact make or model. It looks like your basic typical filter housing, such as:

Thanks.

I did replace the washer using one from the filter replacement kit— maybe I need a thicker one, or made of different material?

I still haven’t had time to get to this due to sick children, changes in my work schedule, etc. I’m hoping to solve the problem this week.

There is a shutoff valve right before the filter.

Is the bolt that’s in there a regular bolt I can get anywhere? I thought it may have been bisected by a hole near the inner end. I could be wrong.