Preway BI28 & BI36 Fireplaces (ID & Specs)
The BI28 and BI36 are model designations, not enough to confirm fireplace dimensions, clearances, or chimney fit. Identify the full model and serial number from the rating plate, then match the unit to its own installation instructions. Until that is done, do not install, alter, or use an uncertain fireplace or chimney system.
Do you remember the look of a Preway fireplace warming a room on a winter evening? If you are restoring one now, the first job is not measuring the opening or choosing a chimney part. It is finding out exactly which appliance you have and what its own documentation allows. A familiar model name does not prove that a fireplace is safe to use.
In my fireplace assessments, I start with the plate, not the visible opening. That order matters: a factory-built fireplace is a listed system, and its chimney, supports, firestop, cap, and approved accessories may all be part of that system. Here is a practical guide to identifying a BI28 or BI36 and checking what can, and cannot, be established from its name.
What the BI28 and BI36 model names tell you
The model name is a starting point for identification, not a complete specification. “BI28” and “BI36” do not, by themselves, verify the firebox opening, heat output, required clearances, chimney size, or permitted installation layout. Those details must come from the rating plate and documentation that matches the exact fireplace.
Find and record the rating plate
A rating plate is the fireplace’s identification label. With the unit completely cold, look for a plate on the fireplace body or in an accessible area identified by its original instructions. Do not remove panels or disturb the chimney to search for one. Photograph the plate clearly, and record every legible detail, including the full model, serial number, fuel type, and any listed standard or revision information.
Also take photos of the firebox, front opening, damper area, visible chimney parts, fireplace surround, and chase. These images can help a qualified professional compare the installed system with the correct instructions. They do not replace those instructions or reveal concealed framing clearances.
| Item to identify | What to record | What not to assume |
|---|---|---|
| Model | Full model designation as printed | That BI28 or BI36 gives the opening size |
| Serial number | Every visible letter and number | That two units with the same model have identical histories |
| Fuel | Exact wording on plate or manual | That the fireplace accepts gas logs or a gas burner |
| Listing details | Standard, label wording, and manual revision, if shown | That a listing can be confirmed from appearance |
| Chimney | Markings and components visible from safe access points | That a pipe that fits is approved |
If the plate is missing or unreadable, the model name alone cannot establish the fireplace’s listing or exact installation rules. Pause before installation or operation. Ask a qualified fireplace or chimney professional to assess the unit, and check with the local authority having jurisdiction (AHJ), the agency that oversees permits and code compliance.
Which specifications must be verified
A safe specification is one supported by the fireplace’s own rating plate and matching instructions, or by an appropriate professional and the AHJ. Do not fill gaps with measurements from a similar-looking unit. For these fireplaces, model-specific values are not established just by the BI28 or BI36 label.
Clearances, framing, and hearth extension
Clearance means the required space between the fireplace or chimney and nearby combustible materials. Framing details explain how the fireplace is supported and enclosed. The hearth extension is the noncombustible floor area required in front of the opening. Obtain all three from the instructions for the exact model.
Do not guess a clearance from the visible surround. Decorative trim can hide framing, while walls and finishes may have been changed since the fireplace was installed. A professional may need to assess concealed areas; a visual check of the room cannot confirm them.
Chimney type and configuration
The instructions must identify the required chimney system and its approved components. Check the specified chimney type and diameter, allowable height and layout, supports, firestop, and termination details. A firestop is a component used where the chimney passes through a floor or ceiling; it is not a substitute for the specified clearances or support parts.
A chimney connection that appears to fit is not proof of compatibility. Do not connect the fireplace to a masonry flue or a different factory-built chimney based on appearance. Treat the fireplace, chimney, firestop, cap, and approved doors or other accessories as one listed system.
Fuel and operating instructions
Confirm that the plate or manual identifies the unit as wood-burning before choosing a fuel or operating method. Do not assume the fireplace can use gas logs, a gas burner, or another fuel. If the documentation permits wood use, follow its instructions for loading, damper position, and the screen or doors.
Use seasoned firewood, and never burn waste or use a flammable liquid to start a fire. Keep the screen or doors in the position specified by the manual. Do not rely on general fireplace advice when the model’s instructions give a different direction.
A safe identification and inspection sequence
This sequence separates what you can check safely from what needs professional verification. Work only with a cold fireplace, and stop if you find damage, missing parts, signs of overheating, or an uncertain chimney connection. Do not use the fireplace while its identity, condition, or required system remains unverified.
- Photograph and record. Capture the rating plate and visible fireplace and chimney parts. Write down the complete model and serial number; do not rely on memory or a partial label.
- Inspect accessible parts. Look for cracks, missing or damaged refractory panels, warped metal, damaged doors or screens, and signs of water entry or overheating. Refractory panels are heat-resistant lining inside the firebox.
- Match the documentation. Find instructions that match the exact model and, where shown, revision. Confirm that the listed chimney components match the instructions. If the manual cannot be matched, ask a qualified professional and the AHJ what evidence is needed.
- Check local requirements. Confirm whether a permit or inspection is required. Have concealed clearances and parts of the chimney that cannot be safely viewed assessed by a qualified professional.
- Use only after clearance to operate. If the identity and condition are verified, follow the model-specific instructions for fuel, loading, doors, damper, and maintenance. Do not test an uncertain system with a fire.
| Finding | Appropriate next step |
|---|---|
| Legible plate and matching instructions | Verify the full installation and chimney system before use |
| Missing or unreadable plate | Do not infer specifications from the model name; seek professional assessment |
| Cracked refractory panel or warped firebox | Stop use and have the unit inspected |
| Damaged or unidentified chimney parts | Do not operate until compatibility and condition are assessed |
| Evidence of overheating or a prior chimney fire | Keep the fireplace out of service pending professional inspection |
Installation decision cases
The examples below are practical decision cases, not documented claims about specific Preway installations. They show how the same identification rules apply to common restoration questions. The outcome in any actual home depends on the unit, its condition, the instructions, and local requirements.
Case: A BI36 with no readable plate
A homeowner can see “BI36” on a sales listing or hear it from a previous owner, but the fireplace plate is missing. The opening may be measurable, yet that measurement does not verify the model, listing, clearances, or chimney requirements. The safe next step is to stop the installation or use decision and arrange an assessment.
A professional may be able to gather useful evidence from visible markings and components, but the model name alone still does not supply missing specifications. Ask the AHJ what documentation or evaluation it will accept before doing work.
Case: A BI28 connected to an unknown chimney
A fireplace appears intact, and the chimney pipe seems to meet the firebox. But its markings are absent or do not match known instructions. Apparent fit does not establish that the chimney, supports, firestop, cap, or clearances are approved for that appliance.
Do not make a test fire to see whether the connection works. Have a qualified professional identify the chimney system and assess accessible and concealed parts. Replace components only after confirming what the exact fireplace allows.
Case: A replacement panel or door is needed
A cracked panel or damaged door may tempt an owner to choose a part by size or appearance. That can create a mismatch in material, fit, or approved use. First identify the complete fireplace and find written confirmation that the replacement is approved for it.
If the exact instructions or written compatibility information cannot be found, ask a qualified professional. Do not cut, modify, or substitute a generic part based only on apparent fit.
Maintenance, repair, and seasonal care
Maintenance should preserve the fireplace as a complete, matched system. Let the unit cool completely before removing ash or inspecting it. Arrange chimney inspection and cleaning based on use and condition; a qualified professional can advise how often inspection is needed for the actual system.
Keep the fireplace dry and address water entry. Do not store combustible items against the unit or within the clearances required by its instructions. Replace damaged parts only with components approved for the identified model. A cracked refractory panel, warped firebox, damaged chimney, or evidence of a chimney fire calls for inspection before further use.
The most serious hidden risk is heat reaching combustible framing through an incorrect clearance or incompatible chimney. A fireplace can look sound from the room while concealed parts remain unsafe. Do not treat a clean face, recent paint, or a successful past fire as proof that the installation meets its requirements.
Conclusion: identify first, then verify
For either model, the dependable path is the same: record the full rating-plate details, locate matching instructions, and confirm the fireplace and chimney as one system. The model name is not a substitute for firebox dimensions, clearance values, a chimney specification, or a replacement-parts list.
If the plate is absent, the documentation cannot be matched, or damage is visible, do not install or operate the unit on a guess. Get a qualified assessment and consult the AHJ. That pause is safer than learning about a hidden clearance or chimney mismatch after the fireplace is in use.
Frequently asked questions
These answers distinguish what the model names establish from what must be checked on the appliance. For safe installation or operation, use the exact fireplace instructions and seek qualified help when identification or condition is uncertain.
Does BI28 mean the firebox opening is 28 inches?
No. The model designation alone does not verify the opening size. Measure only for planning, and use the matching manual or professional assessment for model-specific dimensions.
Does BI36 mean the fireplace is 36 inches wide?
Not necessarily. Do not interpret the model number as a confirmed opening or firebox dimension. Check the rating plate and exact installation instructions.
Can I use gas logs in a BI28 or BI36?
Do not assume so. Use gas logs or a gas burner only if the rating plate and matching instructions expressly allow that fuel and setup.
What if the rating plate is missing?
Do not infer the listing or installation requirements from the model name. Have a qualified fireplace or chimney professional assess the unit and consult the AHJ before installation or use.
Can I connect either fireplace to a masonry chimney?
Do not do so based on appearance or fit. Verify the required chimney type in the exact instructions and have the system assessed by a qualified professional.
Are generic doors, caps, or refractory panels acceptable?
Not by default. Use only parts expressly approved for the identified fireplace, with compatibility confirmed by its instructions or a qualified professional.
Can I use the fireplace while I search for its manual?
Not if its identity, condition, or chimney compatibility is unverified. Wait until those points have been assessed and the proper operating instructions are available.
What damage means I should stop using it?
Cracked refractory panels, a warped firebox, damaged chimney parts, missing components, or evidence of overheating or a chimney fire require inspection before further use.
Who confirms concealed clearances and local requirements?
A qualified fireplace or chimney professional can assess the installation; the AHJ can explain local permit and inspection requirements. Concealed clearances cannot be confirmed by looking only at the room-side finish.
(This article was written by one of our staff writers, Samuel Vance. Visit our Meet the Team page.)
