Debris in combustion chamber - InspectionNews

JD Johnson · #1 (**permalink**) 02-02-2008, 07:41 AM

I have inspected a lot of gas fired water heaters, but have never seen any thing like the metal plates I found on this one. Does anyone have a clue what these plates are from? I wrote it up as a deficent condition that needed corrected, but I don't have a clue what they are, or how they got there...although my guess is they were dropped down from the heat vent.

Thanks for any advice, be careful out there and have a great 2008!

Michael Thomas · #2 (**permalink**) 02-02-2008, 07:53 AM

The flue baffle ("turbulator") detached from its support at its upper end, fell down into contact with the burners, and melted.

http://www.blueflame.org/images/yourwaterheatera1.gif
http://www.whirlpoolwaterheaters.com...s/std_gas6.jpg

John Goad · #3 (**permalink**) 02-02-2008, 09:03 AM

Good find & nice picture JD

Jerry Peck · #4 (**permalink**) 02-02-2008, 01:56 PM

Quote:

Originally Posted by Michael Thomas

The flue baffle ("turbulator") detached from its support at its upper end, fell down into contact with the burners, and melted.

Michael,

Correct, but I always thought that was a strange name as its purpose is to help create a vortex spiral of hot combustion by-products so it goes up the center flue better. Otherwise, there could be turbulence created in the flue, causing a 'boiling up' effect in the air, reducing the efficiency of the upward flow.

At least that's what I learned many years ago (Bob H. will correct me if this is incorrect

).

Michael Thomas · #5 (**permalink**) 02-02-2008, 02:46 PM

Quote:

Originally Posted by Jerry Peck

Michael,

Correct, but I always thought that was a strange name as its purpose is to help create a vortex spiral of hot combustion by-products so it goes up the center flue better. Otherwise, there could be turbulence created in the flue, causing a 'boiling up' effect in the air, reducing the efficiency of the upward flow.

At least that's what I learned many years ago (Bob H. will correct me if this is incorrect

).

My understanding is the intention is to improve efficiency by increasing heat transfer from the exhaust gases to the surrounding material, for example:

"The water heater contains a turbulator in each firetube, which increases flue gas velocity against the tube wall. This increased velocity does two things. 1. Transfers more heat into the water thus reducing fuel cost. 2. Helps in maintaining a cleaner tube wall should combustion adjustment change (which can produce sooting",

pp 12 here:

http://www.hubbellheaters.com/pdf/ModelDFOM.pdf

----------------

Tabulators in residential hot water heaters usually hang by to small "ears", and are sometimes dislodged during shipping or installation, so you can see this on a brand new heater(!)

Here's my verbiage:

Observation: The flue baffel (turbulator) at the hot water heater has become dislodged and has fallen on to the burners below.

Analysis: A missing or damaged flue baffle can affect the efficiency of the water heater and produce unsafe operation. If the water heater is otherwise undamaged, a qualified service person may be able to remove the damaged flue baffle and install a new one. If they cannot, the water heater will have to be replaced. If replacement is required, this will be a substantial expense.

Recommendation: Have a qualified and insured plumber or HVAC contractor repair or replace the water heater as required.

Jerry McCarthy · #6 (**permalink**) 02-02-2008, 03:18 PM

As a wise man once said, "one picture is worth a thousand words."

Jerry McCarthy · #7 (**permalink**) 02-02-2008, 03:22 PM

Enlarged the water heater schematic for older eyes.

Bob Harper · #8 (**permalink**) 02-02-2008, 03:36 PM

Turbulator is for improved heat transfer. Without it, you could have laminar airflow. That means only the boundary layer of hot gases would be in contact with the heat exchanger walls. By creating turbulence, more heat rubs against the heat exhanger, thus improving efficiency.

The current theory is that smoke follows a spiral pattern on its own, all this considered equal. May have something to do with the Coriolis Effect. The turbulator does not speed up gases--it slows them down allowing more time for heat transfer. It adds flue restriction.

The question for this water heater pictured is: did the turbulator fall on its own somehow then get all melted and distorted or was the unit overfired, which resulted in this condition?Either way, the base of the tank may have been stressed to where it will soon fail. Probably ought to replace the entire unit.

Bob

JD Johnson · #9 (**permalink**) 02-03-2008, 03:22 PM

Thanks for all the great advice. We have only about 30% gas water heaters in our area, so it is great to be able to ask for advice from others who inspect these appliances on a more frequent basis!