DL260 – LIMIT SWITCH

Snap-disc furnace high-limit switch from the DL series; the number is the opening (cut-out) temperature in degrees F. It is a safety device that breaks the heating circuit when the plenum overheats, and a limit that keeps tripping points at restricted airflow or a failed blower rather than at the switch. No manufacturer datasheet is published for this number, so reset type and disc size are unconfirmed. Never substitute a higher-temperature limit – that removes the furnace’s overheat protection.

Specifications from our own stock records. The manufacturer does not publish a public page for this item.

Specs

• TypeFurnace high limit, snap-disc
• Opening (cut-out) temperature260 F per our stock records - verify the stamping on the disc
• Close (cut-in) temperatureNot published - differential varies by disc
• ContactsNormally closed, open on temperature rise
• ResetNot confirmed - check whether the part is auto or manual reset
• Data SourceOTP stock record - not manufacturer-verified

What does L200-40 mean on a furnace limit switch?

L is limit, 200 is the temperature in F where the contacts open on a rise, and 40 is the differential, so it closes back around 160F. That is an auto-reset disc. Manual-reset limits have a button and stay open until somebody pushes it. Bring the old one in so we can match the temperature, the mounting hole pattern, and the probe length together.

My limit keeps tripping. Is the switch bad?

Usually not. A limit is a safety reading real heat, and most repeat trips we hear about trace back to airflow - a loaded filter, closed or blocked registers, an undersized return, a dirty blower wheel, or a plugged evaporator coil sitting above the heat exchanger. Check temperature rise against the nameplate range, often 40-70F or 45-75F. Rise above the top number means airflow, not a bad switch.

Can I use a hotter limit if that is what is in stock?

No. L200, L230, L250 and L290 differ only by trip temperature and by base or probe size, and they are not interchangeable. Dropping a hotter limit into a furnace that specced a cooler one lets the heat exchanger run past the temperature it was tested to. That is defeating the safety, not fixing it.

Does insertion length matter?

Yes. A 3 inch probe where 5 inch was called for sits in the wrong part of the airstream, reads low, and trips late or never. Measure the old probe from the back of the mounting plate to the tip.