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Alpine Gas Boiler Venting Problem

Bunk11 Member Posts: 3
I recently had an Alpine alp080bw-2t02 installed to replace a very loud and large oil burner. I have some concerns which have been partially addresses by the plumbing company and I want to get some feedback before contacting them again.

This question has to do with venting and exhaust. There were 3 major issues.

1. There was the slight smell of fumes which I assumed was a new equipment smell as new parts got hot. This did not cause my CO sensors to go off .

2. The intake and exhaust were at 10" center to center when the absolute min. is 12"

3. There is a tiny round window to view the flame color. The color should be primarily blue however it was mostly orange depending on where I placed my eye and what angle I looked.

I talked to the salesman for the company and he set an appointment to come a week later. He explained that an Alpine Rep had said that taking the airtight cover off the boiler, to view the flame caused the air pressure in the system to change and affected the flame. In other words you can't see a blue flame because to do so you have to take the cover off.

 I went home and inspected more thoroughly and discovered a plate was not screwed tight on the left rear, near where the vent and intake attach. I could feel a cool breeze coming from the plate and I smelled some fumes. I called back and they agreed to come out that day and modify the exhaust so it was farther from the intake. They screwed the plate down tighter. I say tighter because I do still feel a very slight breeze at that location and this morning I smelled the fumes ever so slightly, at the top of the basement stairs where it likes to collect.

I am wondering how this unit is constructed? If the front latching panel needs to be airtight for the boiler to fire correctly then that means the intake/exhaust/fire box have open connections to the case of the unit. It is odd that at the plate at the rear I feel very cold outside temperature air but also smell exhaust. It would seem exhaust/intake/burner and the case all are interconnected and a plate with screws that is a weak link.

But why is there a slow but steady flow of air at the plate? I do not have a wood stove or anything which would create a vacuum inside the house. Could the force of heated air escaping through seams, wherever, in the house cause enough vacuum to pull exhaust and intake air into the living space.

Or is it possible that the exhaust and intake were not properly connected to the boiler?? I want to contact the plumbers again but would like to know more.

Thank you.



  • Zman
    Zman Member Posts: 7,107

    The 12" number should be considered a bare minimum, get much more separation if you can. You should also check the manufactures drawing and be sure that all other clearances on the exterior of the building  are being observed. It sounds like you have a cross contamination between the exhaust and intake which is a very bad thing. Post a picture if you are unsure.

    The boiler will burn a bit differently with the door open verses closed. Unless you have a very long combustion air run, I do not think the flame would go from blue to orange. Your installer should have performed a combustion analysis on the boiler when they started it up. The should have a printout to prove it. This assures that the boiler is tuned for peak performance and is helpful for warranty and troubleshooting issue down the road.

    Insist on a combustion analysis.

    Hopefully, when you resolve the first 2 problems the smell will go away. The boiler should not smell.


    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • unclejohn
    unclejohn Member Posts: 1,751
    Oil Burner

    Blue flame? Never seen a blue flame on a oil burner.
  • Ironman
    Ironman Member Posts: 6,686

    The Alpine IS a gas boiler. The OP said it replaced an oil boiler.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Bunk11
    Bunk11 Member Posts: 3
    smell from boiler

    Thanks for the suggestions zman. They did come back and add a vertical extension to the exhaust so it is a good distance from the intake. They also tightened the screws to the plate on the left side where I felt a draft, although I can see it is not a perfect job. There is gasket material that is missing for a short segment leaving a tiny crack where I can sometimes feels that cold draft still. They also said that they used the correct equipment to tune the boiler.

    I do still smell fumes at the top of the stairson rare occasions.

    I am wondering how a correctly installed boiler such as this could produce a smell inside the house? How is it that any gases whatsoever can escape the vent system? Could you explain why this would be related to whether the exterior vents are too close? In other words how could less efficient combustion cause gases to come into the house from the furnace, even if the plate on the side were slightly loose. Thankfully the CO monitors are not going off but this question keeps bugging me.