The short answer
On the BLH family no heat is usually the consequence of a blocked exhaust rather than a broken heater. That is the key departure from the brand-generic page, which opens at the element: on these machines the element is often fine and the safety device in front of it has done its job.
What you observe
- It heated until recently and stopped suddenly — A sudden loss points at a protection device rather than at gradual wear.
- Very long cycles before the heat stopped altogether — Classic history of a restricting duct, and it names the underlying cause.
- Weak heat rather than none at all — Points at a thermostat or a partial element fault rather than an open protection device.
- Heat for a few minutes then nothing — A device opening as the machine warms, which is again an airflow signature.
- NEAR MISS - the drum does not turn at all — That is a no-start or belt fault and belongs on the start page.
Causes, most likely first on BLH
- Thermal fuse or high-limit device open — Ranked first on the BLH family: a large appliance circuit is typically 30 A or higher at 240 V, and these one-shot devices open all at once, which is why the heat stops dead rather than fading. What decides the order here is the protection chain, and on this family that chain is common to every model listed. This moves above restricted or blocked exhaust duct, which leads the brand-generic order, because this family is a single build with fixed access points.
- Restricted or blocked exhaust duct — Second: the duct is the condition rather than the part: restrict it and the protection chain opens, which is why clearing it is the repair and not the preparation for one.
- Cycling thermostat or thermistor — Third: a control sensor that has drifted gives weak heat and long cycles rather than none, which is a different complaint from the one this page opens with.
- Heating element or its circuit — Fourth: a large appliance circuit is typically 30 A or higher at 240 V, so a machine that has lost one leg tumbles perfectly and makes no heat at all.
- Control board or the heat relay — Last: last, because between the duct, the protection chain and the supply there is very little left for a board to explain.
Check in this order, and why
- Disconnect and inspect the whole exhaust duct — Do this first: it is both the commonest cause and the condition that destroyed whatever part failed.
- Feel the exhaust discharge outside while it runs — Warm strong discharge means the duct is clear; weak or cold means it is not.
- Check the outside vent hood opens and is clear — A flap held shut by lint restricts the run even when the duct itself is clean.
- Have the supply checked if the machine runs on two legs — Losing one leg leaves the motor running and the heat dead, which is exactly this symptom.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. A thermal protection device that has opened is replaced with the correct part, and only after the restriction that opened it has been cleared: it opened for a reason, and that reason is still there.
When to call a technician
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Clearing the duct is owner work and is the part that matters. Call for anything inside the cabinet: the protection devices sit next to the heater and are tested live.
Other BLH pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
