Anyone here know anything about oil furnaces?

[bluue13]

Ok so-

I have a oil furnace and tankless hot water. For the past few months I've had a very slow drip out of the discharge pipe. Having done some research I've read that this could be either a water logged expansion tank issue (which I have counted out as I have a new diaphragm type expansion tank and I've checked it out to be working properly), or an issue of high intake pressure from the outside water line, or even a discharge valve stuck open due to mineral deposits or corrosion.

My furnace PSI reads at around 15 when at rest and close to 20 while running. Pretty sure it should stay around 12-15 PSI.


So my question is:
Is it likely that the discharge pipe is dripping because of the higher furnace pressure? Or, is it more likely that the discharge valve is faulty due to mineral buildup inside. I should note that there is a bit of buildup on the outside of the valve where the copper piping exits the discharge valve.

Should I operate the discharge valve and see if this lowers the pressure to a more "safe" level?

I'll come back with some pictures later if it will help the situation.

Thank you in advance and I hope I've been clear. Let me know if I need any more info!

Thanks, Brothers and/or Sisters!
-Greg

 

[badwhale]

The emergency blow off valve is doing what it's supposed to. Mine sorta does what you're describing.

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. Plumber told me that THAT thing is bad on mine, and it's not regulating the house pressure in. When the furnace runs, the psi goes up, and the blowoff valve kicks on.

I turned off the house feed to the boiler, and I just crack it once in a while to keep the system charged. In other words, a "new fangled" convenience device went bad, and I'm back to manual.

Will

 

[Devil Doc]

I have a good relationship with my Oil man. You should too. I'd call him.

Doc.

 

[bluue13]

I have a good relationship with my Oil man. You should too. I'd call him.

Doc.

Yeah, its definitely on the list of phone calls to make. I figured I would ask around here first and see if there were any easy fixes before I had to get charged an arm and a leg.

We actually used to have a service contract with the oil company for $99/yr. For whatever reason they jacked it up to $300/yr so we opted out. Figured one call to a technician would cost about the same or less. (fingers crossed).

 

[grateful1]

What does the manual say?

 

[MadMonk]

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

 

[badwhale]

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

Automatic feed....that's it!

Will

 

[MadMonk]

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

Automatic feed....that's it!

Will

Yeah, as the name implies, monitors low and water, adds it, and then shuts down until it needs more. There really isnt a lot on a burner. Whatever you do, do not touch the Transformer. Can kill you.

 

[bluue13]

What does the manual say?

Gary, unfortunately the previous homeowners did not keep the manual handy, so I've been using the all great and powerful google.

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

Automatic feed....that's it!

Will

The automatic feed is actually working fine. I tried bleeding the discharge valve for a few seconds and it took the pressure down a little and I could hear the water feeding back in. Since then the drip has actually stopped. I'm thinking that discharge valve itself may have just been a little loose. In any case I'm still going to have someone come look at it. I'd hate for there to be a bigger problem and for it to go unnoticed.

 

[badwhale]

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

Automatic feed....that's it!

Will

Yeah, as the name implies, monitors low and water, adds it, and then shuts down until it needs more. There really isnt a lot on a burner. Whatever you do, do not touch the Transformer. Can kill you.

So can the lugs on my 200 amp service panel, uncovered about 2 feet away

Will

What does the manual say?

Gary, unfortunately the previous homeowners did not keep the manual handy, so I've been using the all great and powerful google.

There's another mechanism, which I don't know the technical term for which allows water from the house to keep the system at a set pressure. ....

Will

I think you might be talking about the Low water cut-off / Automatic feed. Those go bad a lot. I worked on oil burners a lifetime ago, as a kid. My Cousin had a biz, and I did about 2 years with him.
Unfortunately, I can't remember a lot as this was well over 30 yrs ago.

Edit to add: do a search on how to check that part...I know I used to do one, and it was pretty simple/

Automatic feed....that's it!

Will

The automatic feed is actually working fine. I tried bleeding the discharge valve for a few seconds and it took the pressure down a little and I could hear the water feeding back in. Since then the drip has actually stopped. I'm thinking that discharge valve itself may have just been a little loose. In any case I'm still going to have someone come look at it. I'd hate for there to be a bigger problem and for it to go unnoticed.

Yeah, it feeds it back in fine....then it subtly doesn't stop. If it didn't feed water back in, you'd have zero pressure, and would be reporting a different problem.

Will

 

[bluue13]

Yeah, it feeds it back in fine....then it subtly doesn't stop. If it didn't feed water back in, you'd have zero pressure, and would be reporting a different problem.

Will

Makes sense. Gonna call someone in to take a look at it.

Thanks for the help, everyone!