Traulsen SN2: the coil sensor has failed
The coil sensor tells the control when the evaporator has shed its frost during defrost.
Mon–Sat, 8am–8pm
- Sensors and probes
- Commercial controls and board repair
- Source: Traulsen
Book a visit
Three short steps, about a minute.
or call (844) 571-4566
Loading appointment form…
The appointment form couldn’t load. Please try again.
What SN2
actually means.
The coil sensor tells the control when the evaporator has shed its frost during defrost. With SN2 showing, defrost timing is no longer guided by the coil, so frost and ice can build up. Traulsen marks SN2 as a service message.
Traulsen commercial appliance display
What to do when SN2 shows on the commercial applianceKind of codeSensors and probes
A probe is handing the controller a reading it cannot trust, or none at all: a box or coil sensor torn loose from its clip, a fryer probe coated in carbon from oil left too long between filterings, a combi core probe with a kinked cable, or a connector gone green from steam and cleaning chemicals. The unit then runs on, stops, or shuts the heat or the cooling off to protect itself. Letting it cool and restarting it as the manual describes is fair; a probe that still reads wrong sits behind a panel, and that is a visit.
Usually leads toCommercial controls and board repair
Controllers, touch panels, relays, contactors and interlocks tested, and replaced only when the evidence says so.
Shows up asCommercial Appliance Error Code on a Combi, Fryer, Dish Machine or Laundry Display
A commercial appliance error code appears as letters or numbers on a combi, fryer, reach-in controller, dish machine or laundry machine display, or as a flashing light or an alarm tone.
MakeTraulsen
A Traulsen cabinet that starts to drift gets its visit as soon as the food inside has a safe place to go.
SourceTraulsen All Series quick reference guide, owner's manual TR35924 rev. C (2015), linked from traulsen.com owner's manuals
Shown by the control on R & A Series cabinets, as listed in Traulsen's quick reference guide TR35924 (rev. C, 2015). Units built after July 2025 carry the Smart Control, which keeps alarms in a menu instead (see PFA).
Before you book,
in this order.
Each step comes from Traulsen's own guidance for SN2 on its commercial appliances. Follow it to the end: the last card says whether this is a visit.
Keep logging food temperatures twice a shift.
Look through the grille for heavy frost on the coil and note what you see.
Book a visit before the coil ices over and airflow stops.
Still there?
It usually turns into commercial controls and board repair. Book with the code and the model number.
What not to do
SN2 does not mean the cabinet is warm yet. It is also different from DEF ERR, which reports a defrost that did not finish.
What you may
notice with it.
The commercial appliance problems SN2 tends to arrive with. Answer these at the commercial appliance before anyone is booked.
All problems
Where SN2 usually leads
Commercial controls and board repair.
Traulsen
commercial appliances.
A Traulsen cabinet that starts to drift gets its visit as soon as the food inside has a safe place to go.
Traulsen commercial appliance repairMore Traulsen codes
Sensors and probes on other makes
Commercial cold storage
Reach-in and pass-through cabinets, walk-in coolers and walk-in freezers, prep and sandwich tables, undercounter units and blast chillers that hold a kitchen's food at safe temperatures.
Commercial cooking equipment
Fryers, griddles, charbroilers, restaurant ranges, convection and combi ovens, steamers, kettles, holding cabinets and toasters, on gas or electric, that make up the hot side of a kitchen line.
In Traulsen's own words
SN2: Indicates coil sensor has failed.*
Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Shown by the control on R & A Series cabinets, as listed in Traulsen's quick reference guide TR35924 (rev. C, 2015). Units built after July 2025 carry the Smart Control, which keeps alarms in a menu instead (see PFA).
Traulsen SN2 commercial appliance repair,
where we come out.
The same visit in every metro below: the code, the model number, and a diagnosis before any part is ordered.
All service areasTampa BayFL · 31 areas
Miami / South FloridaFL · 47 areas
New York MetroNY · 75 areas
HoustonTX · 36 areas
ChicagoIL · 50 areas
Los AngelesCA · 95 areas
San DiegoCA · 31 areas
Questions
about SN2.
Can I clear SN2 myself?
Why does my Traulsen show SN2 and frost on the coil?
Can I defrost a Traulsen by hand while I wait?
Will SN2 on a Traulsen stop the unit?
Back to your everyday
Still showing SN2?
A booking with a code goes further when it has the code as shown, the model and serial from the data plate, and a word on whether the unit still holds temperature, heats, rinses or spins. With those three, the office can match the likely part to your unit the same day.