Doors on Prefab

[Skimple]

OK, I think I looked through the whole site and couldn't find this information, so here goes.

In Q&A 748 you mention that using "generic" fireplace doors can be very dangerous with a prefab, but you don't say why. I have a Majestic MHC36 prefab which was in the house when we bought it. The doors that are on it sure look like the ones they sell in Home Depot. The insert is set back 4" inside a brick facade. The doors are installed on the brick facade.

I have contacted Majestic to get a copy of my owner's manual and installation instructions, but the insert is ~20 years old now, and it took them a couple of weeks to find any information on it. It called out a fireplace door that is no longer in production.

What should I be looking for to find out if my fireplace doors are dangerous?

 

[elkimmeg]

Pre fabs are installed within combustible framing members unlike a concrete and brick fireplace. Your unit had doors that were built and tested for that unit. They are the only doors that were made and tested to function saftely with your pre Fab
Reto fitting generic doors, present variables and characteristics not tested. These doors are tested for brick chimneys. There is know way to determine what dangers exist closing them while running the pre Fab. The retro fit could produce an entirely different inlet air flow the air flow vollume could be different Even its setup and location can cause different characteristics than the factory tested one with the original unit. You are playing with fire co and co/2 gasses. Results could prove deadly. Are you willing to take that gamble? reyling on someone elses un documented retro fit?

 

[Skimple]

Well no, I don't want to rely on anyone else's retrofit (particularly the joker that owned this house before me). I wouldn't have even looked into it if my wife hadn't decided she didn't like the doors anymore.

The doors are not set inside the firebox, and the firebox doesn't even look like it has mounting locations for doors. There are no markings on the existing doors, but they were always a loose fit and look pretty "generic" to me. The prefab has outside air draw, and I usually don't close the doors while I am operating it, and we haven't had any problems that I am aware of.

What are my options if Majestic doesn't make a door for this model anymore? I really don't want to replace the entire insert just because the doors may or may not be the right ones. Is there some way to test it in the home to see if the air flow is off?

 

[Skimple]

I just talked with CFM again. The doors that were certified for my fireplace were model MGE36. These are no longer in production, and CFM cannot suggest a substitute (due to potential lawsuits presumably). The nice gentlman from India suggested that I contact "one of the many suppliers you can find on the internet" with the dimensions of my opening. These suppliers should be able to help me.

OK, so he bailed. So my question now is, how does Fireplace Door Supplier know what doors will work properly with my unit?

I'm not trying to be cheap. I'll pay the money to get a good door, but how do I know that I am getting the correct door for my unit?