Unreal HE corrosion

JerseyWreckDiver

These pics are from a 7 or 8 year old, oil fired, Burnham HW boiler I looked at the other day. Looks like new, almost, on the exterior. The installation isn't the worst I've ever seen. But before I laid a hand on it I noticed a couple spots of pretty good moisture in the chimney structure a couple/few feet off the floor but still well below the flue connector nipple. Then flue gas condensation induced corrosion seeping out the seems on the connector elbow. So I open the burn chamber inspection port and see the worst corrosion I've yet laid eyes on.

There was a tag from the oil supplier/maintenance company with records of annual service every year, but this is one of two companies I typically tell people to stay far away from for exactly this reason. Though when I fired it up the flame looked fine and there was no backdrafting through the inspection port.

The oil feed line is buried in or below the slab and there is a high water table. I'm leaning toward a hole in the feed line that the burner is sucking water in through. Anybody have other likely culprits?



The first two are looking straight to the left inside the inspection port at the long horizontal fins on the vertical sidewall of the fire chamber - the last is looking hard right

Steve Whitbeck

moisture

I doubt that it is water getting into the oil. You would see that in the nozzle and the oil filter.

Is it a damp basement during some periods of the year?

It looks to me like damp environment corrosion.

Is it possible that there is a water leak when it is firing that is causing a wet chamber?

What is your return water temp?  Is the boiler running cold/underfired?

JerseyWreckDiver

No, not damp

No, the basement isn't damp. I've been in really damp basements and not seen anything on this level. The gas fired water heater right next to it looked clean as can be and is the same age.



I did this as part of a property inspection so I'm not allowed to take off the filters and open up the burner. I was tempted to bleed some oil from the burner but the listing agent was skulking around...



The house has been vacant for a while and was cold when I got there. I fired it up and let it run through a full cycle just to check function/temp/pressure and look at the burn.

Ron Jr._3

Have any pics

of the piping and outside of the boiler ? What kind of heat is the boiler connected to ?

Could be there was no low limit protection of the boiler and condensation rotted it out . Or could be an internal leak that wasn't notcied for a long time .

Here's a pic of a Burnham steam boiler that corroded from too much fresh water makeup .

JerseyWreckDiver

Yikes

Yah I'd love to be able to pull this one apart and see whats happening inside. I ah, "bumped" into the flue connector when the agent went upstairs but is was too tight...



It was fin/tube BB radiation, diverter Tee system. I rarely see a boiler with any kind of controls beyond the hydrostat that came with it (cept in my own basement & on this board)



Here's a pic of the boiler and the chimney base.

Constantin

Couple of thoughts...

... are they cold starting this boiler?

... were they in the habit of turning it off in the summer?

... does the chimney need to be lined because it's too big for this appliance?

... when was this unit allegedly last inspected?

... is a barometric damper fitted?



To my untrained eye, it looks like the chimney is having a condensation issue. If the boiler and the gas water heater share the same flue, that's probably the cause. Up here, one chimney was demolished by a gas water heater, one heating cycle at a time. By the time we bought the house, a hole big enough to put a fist through had spalled through the chimney. At the very least, I'd get the chimney lined, ideally with separate flues for water heater and boiler/

Big Ed_4

Cracking Issues

Pull the side clean out covers and look for cracking along the casting ... There has been casting cracking issue in that general area ...

JerseyWreckDiver

some info

I am working for the people looking to buy this house so information about history is very limited. It's an estate sale and has been vacant for more than a year. Here's what I know.



... are they cold starting this boiler?

As far as I know, no.





... were they in the habit of turning it off in the summer?

I don't know, but I would assume so. Why would this be a problem?





... does the chimney need to be lined because it's too big for this appliance?

No, it's an 8x8 square clay tile flue. It had a rain cap on top that didn't want to come off and I was standing at the peak of a 10/12 pitch roof so I didn't get to look down it but everything I could see gave no indications of damage or flue gas condensation at that end. (I'll post a picture)





... when was this unit allegedly last inspected?

Last fall according to the maint. tag.





... is a barometric damper fitted?

Yes, I don't think it was balanced properly but I didn't use any instruments to confirm one way or another.







To my untrained eye, it looks like the chimney is having a condensation

issue.

This was my first thought, but after poking around it seemed to be more "in the boiler" then in the flue. The flue connector knuckle had corrosion seepage at the joints but looking inside the horizontal section through the damper, everything looked normal.



If the boiler and the gas water heater share the same flue,

that's probably the cause.

This was one of the first things I mentioned was that it shouldn't be that way. But in my world this is a sticky issue. Some municipalities prohibit it other don't. The better HVAC people I know won't install gas & oil on the same flu and many others do. Honestly though I couldn't find anything there to pin it on the WH.



Up here, one chimney was demolished by a gas

water heater, one heating cycle at a time. By the time we bought the

house, a hole big enough to put a fist through had spalled through the

chimney. At the very least, I'd get the chimney lined, ideally with

separate flues for water heater and boiler/



Thanks for taking the time to comment.

Mike Kusiak_2

Low temperature operation?

You mentioned that the house has been vacant for a year. I assume that the heat was left on to prevent freezing of the piping? If the thermostat was set to 55 degrees or less, perhaps the boiler only ran for short periods of time to maintain this low temperature and never got above condensing temperature for long periods, especially in spring and fall.

What was the aquastat setting and was it set to maintain a constant water temperature around 180, or does the burner only fire when there is a thermostat demand for heat?