Flue pipe

ed wallace

thats a big fire hazard can you post more pics? are the furnaces 80+ or90+ furnaces?

Bryan Cummins

Flue pipe

There are four gas fired water heaters {atmospheric type} and four power vent gas furnance's all ties into a box at the base of chimney {new built home aprox. 4 yrs old}. Also all the flue piping is insulated entirely. What I found was inside the burning chamber of the water heaters; I found a build up of scale. I have two questions
1.Can you insulate flue pipe,and if not why?
2.Can you vent power vent and atmosphereric gas appliance into the same chimney?

Bob Harper_2

You cannot common vent atmospherically vented appliances with those under positive pressure.

You cannot wrap, cover, insulate or conceal vent connectors.

HTH,
Bob

Bryan Cummins

Thank you Bob Harper did you see my pictures what do you think. I just need some technical answers so I can convince the owner to correct the situation

Bob Harper_2

IFGC 503.10.2.3- vent connectors shall not be covered with insulation.

501.6 Where an appliance equipped with a mechanical forced draft system creates a positive pressure in the venting system, the venting system shall be designed for positive pressure applications.
503.3.3.4 Vent connectors serving equipment vented by natural draft shall not be connected to any portion of mechanical draft systems operating under positive pressure.

FYI: if you have Cat. I fan assisted applianes, they are considered natural draft.

The vent connectors have states clearances, which are air spaces. The insulation violates states clearances. Even if you fill it with concrete, it would be incorrect. You need air spaces to cool the pipe. Also, the pipe needs to be visible and accessible for inspection, repair and replacement. That insulation appears to be just class 1 duct, which is considered a combustible.

HTH,
Bob

Timco

I doubt the installation manuals will say anything about venting atmospheric & positive pressure appliances, but the IFGC will. I am away from my desk, but look there. There is plenty of info on this being a no-no. Insulating the pipe will just make the ex gases hotter as the heat will not x-fer through the pipe. No benefit from that...I would read the install manual for the power vented appliance and see if it lists approved venting methods. Chimney is likely not one of them if it is a 90%er...

Tim

Unknown

Check to find out if

the furnaces are Category I, III or IV, it will tell you this on the rating plate. The code allows fan assisted to be vented with natural draft units (fan assisted furnaces or boilers Category I with natural draft water heaters). It is my experience however that this does not really work most of the time. Need to know the Category to advise you further. Example if those furnaces are Category III or IV then they can not be vented with a natural draft appliance. They also may be able to be relocated to side wall venting to solve the problem.

Bryan Cummins

Here are some more pictures. I am not sure of the furnace's efficiency,however I will look. One more crazy thing to add to this whole situation. There is a dryer in the same room. Now these are closed combustion water heaters with the screen on the bottom.Lint everywhere!It's amazing what you can run into.

Unknown

Brian, shut all of those units off

and red tag them. Those FVIR water heaters run with excessively high flue gas temperatures already. With that insulation on them they are a fire hazzard. They are also probably running with high levels of CO if the air openings are plugged with lint. A DEATH TRAP WAITING TO HAPPEN!!!

Fan assisted units with FVIR water heaters will never work so the entire job is a nightmare and going to seriously hurt someone.

Have the landlord get in touch with me and I will help him to make a sound decision as to the safety of his tenants My phone number is 401-437-0557.