Front Inner Doors

Front Inner Doors

Our durable front inner doors provide secure, heavy-duty thermal protection for industrial boilers, ensuring seamless equipment compatibility.

*These front inner doors are compatible with Cleaver-Brooks boilers.

  • 465-183
    36 inch
    15-40 HP
  • 465-1322
    48 inch
    CB
    50-100 HP, N/S
  • 465-1323
    48 inch
    CB
    100A-125A HP
  • 465-1324
    48 inch
    P&M 50-60 HP, CBH 50-100 HP
  • 465-311
    48 inch
    50-100 HP, O/S
  • 465-1330
    60 inch
    125-200 HP
  • 465-1703
    Ohio Special
    60 inch
    125S-225S
  • 465-138
    78 inch
    250-350 HP
  • 465-167
    96 inch
    400-800 HP

Get a Quote

"*" indicates required fields

This field is for validation purposes and should be left unchanged.

In-stock items. Order by 3:00 PM EST for Same-Day Shipping.

*Halmar Corporation offers many Cleaver-Brooks aftermarket parts. Halmar Corporation is not a factory authorized sales representative for Cleaver-Brooks, nor is Halmar Corporation affiliated with Cleaver-Brooks in any way. Cleaver-Brooks is a registered trademark of Cleaver-Brooks, Inc., Thomasville, GA.

Some aftermarket parts may be made by other manufacturers.

Can’t Find the Front Inner Door
You’re Looking For?

We carry a large inventory and if we don’t have what you need, we can help track it down for you. Give us a call.

Frequently Asked Questions About Front Inner Doors & Insulation Kits

The front inner door of an industrial boiler acts as a critical thermal barrier between the high-heat combustion chamber and the external environment. Over time, the refractory insulation on these doors can degrade, crack, or pull away due to constant thermal expansion and vibration. If this insulation fails, excessive heat can transfer to the outer door and burner components, potentially warping the metal, damaging sensitive controls, and significantly reducing overall boiler efficiency by increasing radiative heat loss. Replacing old, worn insulation with a high-quality kit ensures your boiler maintains its design efficiency and protects surrounding components from heat damage.

When selecting a replacement kit, it is vital to ensure that the insulation material is specifically engineered for the high-temperature demands of your boiler’s internal environment. Look for kits that provide a precise, custom fit for your specific boiler model, as gaps or improper sealing can lead to “hot spots” and localized overheating. A high-quality kit should include durable, thermal-shock-resistant materials that can withstand repeated firing cycles without crumbling or shrinking. Additionally, choosing a kit that is designed for straightforward, secure installation will minimize your downtime during maintenance turnarounds and ensure a long-lasting, reliable thermal seal.