On the surveyed Bosch boiler the front door measured 96 °C and the burner flange around the throat reached 146 °C — FLIR-measured, bare. The door also hinges open for burner service.
Figures are for one boiler. Surface temperatures from a real FLIR survey of a UK commercial boiler house; CAD surface areas uplifted ×1.4 for bolts and irregular geometry; ISO 12241 steady-state (50 mm core, ambient 28 °C, air movement 0.5 m/s).
Drag-free toggle. Visible in this view: front (boiler) door (96 °C) and burner flange (146 °C) — bare.3D model: Inzonex · equipment rights belong to the manufacturer
The front of a Bosch package boiler is large, hot and movable — the three properties that defeat rigid insulation. The door runs at 96 °C over a 2.3 m² face and the burner flange at 146 °C, yet both have to open for burner service.
A buttoned removable panel is made to the door and hinges with it: insulated when closed, out of the way when open. The burner mounting and sight port stay clear.
| Element (this view) | Temp °C | Area m² | Bare W | Insulated W | Surface °C | Cut |
|---|---|---|---|---|---|---|
| Front (boiler) door | 96 | 2.33 | 2,530 | 150 | 30 | −94% |
| Burner flange | 146 | 0.85 | 1,780 | 60 | 30 | −97% |
| Front / burner door, per boiler | 3.18 | 4,310 | 210 | ≤45 | −95% |
ISO 12241, 50 mm Inzonex modular core, ε(bare)=0.9, ε(jacket)=0.85, hconv at 0.5 m/s. Insulated figures are conservative steady-state.
The front door carries the burner and closes onto the furnace tube — a 2.3 m² face the FLIR survey measured at 96 °C. It hinges open for burner service, so a fixed jacket fails here; a buttoned removable panel insulates it and opens with the door.
The burner mounting flange ran hottest on the front at 146 °C — a concentrated ring of loss around the burner throat. A shaped removable collar insulates the flange while leaving the burner and sight port clear.
Every module here re-opens for access.
Every surface on this view is covered by an Inzonex modular removable panel: a PAROC stone-wool core (50 mm) in a silicone outer shell — or a more durable PTFE shell as an option. The form-fitting build unbuttons for access and refits after each maintenance cycle. The outer surface drops to a touch-safe ≤45 °C.
Industries that run this boiler
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Carbon hub → 3D modelRotate the Bosch UL-S model, toggle bare vs insulated, and jump to every other surveyed surface.
Open 3D model →FLIR-measured at 96 °C bare over a 2.3 m² face; the burner flange beside it reached 146 °C.
Yes — a removable panel hinges with the door, insulated when closed and clear of the burner mounting and sight port when open.
About 30 °C — below the 45 °C touch-safe threshold — roughly a 94% cut in loss.
Selected readings from this boiler survey. This surface is the marked point.
On the Bosch UL-S the same view carries two items, not one: the door itself at 2.33 m² and 96 °C, and the burner flange ring at 0.85 m² and 146 °C — the hotter of the two by 50 degrees. Together they are 4,310 W bare. The flange stays covered when the door is opened.
The sequence for taking a module off a burner door, opening the door and refitting is the same on both machines and is set out once, on the Cochran door page.
| Survey | Bosch UL-S, front / burner door. FLIR S62 Pro, emissivity 0.90, reflected 25 °C, 3 m, full radiometric correction. Peak on this view 146 °C. |
| Geometry | Rebuilt in CAD from the surveyed machine. This view carries 2 element group(s) and sheds 4.3 kW bare. The ×1.4 factor is a geometry allowance for bolts, seams and irregular surface — it is not a measured area. |
| Calculation | ISO 12241 steady state. Heat loss is calculated from the measured surface temperature and the modelled area — it is not metered. Full method, basis and limits. |
| Largest single item | Front (boiler) door, 2.5 kW on this view. |