The short answer
On the Blomberg BLH dryers specifically, this fault sits one level below the brand-generic answer: the models in this family share a layout, and that layout changes which check comes first. The single most common cause of a dryer that will not heat is a vent the exhaust cannot get through. The heat source is fine; the safety device in front of it has done its job. If you smell gas at any point: do not switch anything on or off, leave the building, and call the gas utility or 911 from outside.
What you observe on these models
- Clothes take two or three times as long as they used to — Partial airflow restriction rather than a complete loss of heat.
- A burning or scorched smell during a cycle — Lint accumulated somewhere it is being heated, which is the urgent case.
- The drum turns normally but the load comes out cold and damp — Mechanically healthy, thermally not — the classic presentation.
- NEAR MISS — it heats but stops partway through — A cycle that ends early with heat present belongs on the cycle-fault page.
Causes, most likely first on this family
- Exhaust vent blocked or crushed — First on the list because it explains every symptom on this page at once — no heat, long cycles, a hot cabinet and a scorched smell.
- Cycle selection or sensor calibration — Last: an air-fluff or no-heat programme produces exactly this symptom deliberately, and a moisture sensor coated with residue ends cycles early.
- Gas supply off, or the burner not igniting — Fifth, and it is checked at the valve rather than inside the appliance.
- Where this order differs from the brand-generic page — On this family the access route decides the sequence. The cause that moves up is the one reachable without removing a panel on these models, and the cause that moves down is the one that needs the cabinet opened — so the ranking here is ordered by what this platform lets you confirm first, not only by raw likelihood.
Check in this order, and why
- Pull the lint screen and hold it up to the light — You should see through it easily. A screen sealed with fabric-softener residue looks clean and passes almost no air.
- Check the programme selected — An air-fluff or no-heat setting produces a perfect tumble with no heat by design, and it is easy to select accidentally.
- On a gas machine, confirm the supply valve is open — The handle should be in line with the pipe. Do not go further than the valve.
- What the family layout dictates here — On these models the components involved are not equally accessible, and the order reflects that. Working it as written means you reach a conclusion with the least disassembly, which matters more on this platform than on a machine where everything is behind one panel.
Before you open anything
Safety
Switch off at the breaker before any cover comes off. Lint is combustible, so treat a restricted vent as a fire risk and not merely as a performance problem, and never run the machine with the duct disconnected for longer than a brief test.
When to call a technician
The line is the cabinet on an electric machine and the supply valve on a gas one. Airflow work is yours; elements, thermal devices, motors, igniters and gas valves are not. A scorched smell is an immediate call rather than a diagnosis.
Other faults covered for this family
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Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
