Unconventional boiler venting

[Kenton H. Shepard, CMI]

This setup is unusual here. The vent setup will add cool air to exhaust gases and allow it to draw, but is it OK? Does the draft diverter need to be where the vent exits the boiler cabinet? What's the "T" with the clear plastic tube coming out the bottom?

[sfalvey]

I have seen the plastic tube on one boiler before. The boiler was gas and not oil. In my scenario, the plastic tube was a drain for the condesate (sp?) removal so the water would not go back to the unit.

My own boiler has a similar setup except the drain is down near the floor away from the combustion chamber.

[Kenton H. Shepard, CMI]

Dry climate/ propane/ mid-efficiency boiler, I'm surprised condensation is a problem, but you're right, Scott, it's obviously for condensation. I'm just wondering why this one and not all the other mid-efficiency boilers.

[sparksnmore]

Just a guess but a lot of flue pipes have had drains added because they do not draw properly so the humidity condenses inside the pipe rather than get all the way outside.

Not that I've personally seen many but I've seen a lot of pictures when the Metalbestos rep put on a slide show about improper flues.

I might add that their slide show is both very interesting and very informative and if you ever get a chance to see it you'll be glad you did although it does contain several death by Carbon Monoxide related stories.

[Kenton H. Shepard, CMI]

How about this...

Installer forgot to bring a draft diverter with him (this home is 20 miles up into the mountains) so he invented this funky monkey draft diverting system.

During system operation, the exhaust gases cooled excessively, causing condensation which ran back into the boiler, rusting the heat exchanger (piture here is from the same home/same boiler) and causing some kind of damage which the installer caulked... badly.

Instead of installing a proper draft diverter, he installed a "T" with a condensate drain.

This boiler was short-cycling at the inspection. I don't know why.

P.S. Client was a construction defect attorney form California who makes a lot of money defending home inspectors! After he told me I told him I needed five more hours to finish up. We all laughed.

[Patrick Bolliger]

Kenton ,
Maybe the altitude at that location is the question on that setup?
Perhaps that is a "high altitude" install for a boiler. Was there a fan in that closet? Is it a natural draft system?
I have seen in Summit county a boiler and water heater @ 9,900 feet with added combustion and draft air supply fan. Heat and flue /chimney draw work hand in hand so I don't think "cooling" down a flue is productive.
If hot combustion gases get cooled down then moisture maybe a problem and draft maybe a bigger problem...

Regards...
Time to go skiing....

[Gary Reecher]

Sidewall venting of mid efficiency boilers is a little different than 80 percent efficiency furnaces. Depending upon the manufacturer they may require the use of stainless steel vent system as pictured above. Will have to check on the validity of concentric venting through the combustion air pipe. Now other manufacturers may require B vent material with a sidewall venting kit.