De Dietrich Soft Lockout / Demand Loss

Furnace starts normally but shuts down after a few minutes without error code

Possible Causes

Room thermostat reaching setpoint too quickly, Flow temperature limit reached due to low circulation, Internal anti‑cycling timer in De Dietrich control, External control removing demand

How to Fix / Troubleshooting

Safety: No immediate hazard, but system comfort is affected.

Steps:

Check thermostat setting and location: Increase setpoint slightly and ensure thermostat is not in a hot or draughty area.
Open valves: Ensure enough radiators are open to absorb heat.
Review control settings: On De Dietrich controllers, reduce anti‑cycling time if set too high (installer level).

Professional help: A technician can optimise control parameters and check for circulation issues.

Repair Difficulty

Easy 2/5