Dettson Pressure Switch or Draft Interruption

Dettson furnace starts but shuts off after a few seconds without noticeable heat.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Weak inducer motor, Intermittent pressure switch, Blocked intake/exhaust, Water in pressure switch tubing

Safety first: Turn off power and gas before servicing.

1. Inspect intake and exhaust: Check outside terminations for ice, snow, or debris. Clear any obstructions.
2. Drain tubing: Remove pressure switch tubing and blow through it to clear water or debris. Reinstall securely.
3. Test pressure switch continuity: With inducer running (advanced DIY), verify the switch closes. Replace if intermittent.
4. Evaluate inducer: If the inducer is noisy or slow to start, it may need replacement.

Medium 3/5

Pressure Switch

Check Price on Amazon

We may earn a commission from links on this page.