Majestic Fireplace Inserts

Unfortunately, we do not carry a 45,000 BTU direct vent insert.

This part can be special ordered at a cost of $103.81 with shipping included and no sales tax. Please note that this is a non-stock item with a lead time of 4-6 weeks prior to shipping. If you would like to order this part, simply call in and reference the part number.

Unfortunately, I can not locate a manual based on the model number you have provided. If you could, can you please provide a picture of your fireplace's data plate?

This is approved for use with vent free gas logs, so long as the chimney is intact and a Adjustable 4 Inch Fireplace Hood is installed.

The manual for the MBU36 and MBU42 does indeed indicate that the unit is only rated for use as a vented appliance and should not be utilized with a vent free gas log set. This series was manufactured before vent free log sets became popular. As such, the extra clearance that is needed to ensure safe operation was not factored in when building this model. Installing vent free gas logs could cause the top of the unit to overheat and char the wood framing above the box. I do not recommend installing vent free logs for this reason.

After a bit of searching through the Majestic archive, I was able to locate a copy of the original manual for this unit. Page 10, section G-3 of the manual makes the following statement in regards to a combustible mantel: "Do not install combustible mantel closer than 17 inches above fireplace opening for R36 or 15 inches above grill opening for RC36." Because you have the latter of the two models, the 15 inch clearance requirement would apply to you. There is also a graph in the manual that indicates the safe zone for adjacent mantel surround legs. I will send a copy of this manual in another email. Please forgive the poor quality, as it appears the manufacturer scanned a physical copy into their system.

Per the manufacturer, the original blower motor has been discontinued, however a direct replacement is available. You can utilize the housing from the existing blower and bolt it to the replacement motor.

After speaking to the manufacturer, they have confirmed that this unit is set up slightly differently from others they have produced. There should be an air control lever at the front left side of the unit. Pushing the level down toward the hearth will open the outside air door and pulling the level up and over, closes the door. The combustion air is ducted to the extreme front left and right corners of the lower hearth panel and drawn into the fireplace from there.

These units are designed so that the air intake opening is located directly behind either the left or the right refractory panel. If either panel was removed, you should be able to clearly see the opening. The unit is designed so that the combustion air will be pulled around the seams of the refractory panels. Usually, air is only pulled in from the outside when a fire is burning and creating a strong enough negative draft for the combustion air to be drawn around the gaps in the refractory panels. It is possible that the tightness of your home or other appliances that require combustion air are causing the issue, but the chimney itself may also be causing the problem if it is too short to create adequate draft. If the combustion air intake was kinked or bent at any point, this may also be a contributing factor.

Per the manufacturer drawing, this insert has an overall height of 23 7/8 inches. If you are able to remove the metal smoke shelf or some of the refractory liners, you may be able to fit the unit. This model has manual controls on the gas valve, but it is remote ready, meaning that a manual wall switch, wall thermostat, or hand held remote could be used.