True P1: the Dixell thermostat probe has stopped reading
On True units with a Dixell control, probe 1 is the thermostat probe that sits in the return air and decides when the compressor runs.
Mon–Sat, 8am–8pm
- Sensors and probes
- Commercial controls and board repair
- Source: True Residential
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What P1
actually means.
On True units with a Dixell control, probe 1 is the thermostat probe that sits in the return air and decides when the compressor runs. When the control reads it as open or shorted it shows P1. Without that probe the control cannot hold the set temperature properly.
True Residential commercial appliance display
What to do when P1 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.
MakeTrue Residential
A True cooler or prep station in a restaurant is looked at once the kitchen confirms where the held food is sitting for now.
SourceTrue Commercial Refrigeration General Control Guide, P#811072, rev. C (09/2025)
Listed in the Dixell display code table of True's general control guide (rev. C, 2025); the same guide names p1 as the thermostat (return air) probe.
Before you book,
in this order.
Each step comes from True Residential's own guidance for P1 on its commercial appliances. Follow it to the end: the last card says whether this is a visit.
Check the food temperature with a separate thermometer right away and log it.
If the cabinet is warming, move food that must stay at 41°F or below to another unit.
Do not unplug and replug repeatedly; note the time P1 appeared and book a visit.
Still there?
It usually turns into commercial controls and board repair. Book with the code and the model number.
What not to do
P1 is not a warm alarm, though a warm cabinet may follow. P2 is the coil probe, which mostly affects defrost.
What you may
notice with it.
The commercial appliance problems P1 tends to arrive with. Answer these at the commercial appliance before anyone is booked.
All problems
Where P1 usually leads
Commercial controls and board repair.
True Residential
commercial appliances.
A True cooler or prep station in a restaurant is looked at once the kitchen confirms where the held food is sitting for now.
True Residential commercial appliance repairMore True Residential codes
All 14 True Residential codesSensors 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 True Residential's own words
P1 Thermostat probe failure
Every code on this site is taken from the manufacturer's documentation, never from a forum or a parts listing. Listed in the Dixell display code table of True's general control guide (rev. C, 2025); the same guide names p1 as the thermostat (return air) probe.
True Residential P1 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 P1.
Can I clear P1 myself?
Can a True keep cooling with P1 on the display?
How does a technician test the True P1 probe?
Is P1 on my True caused by the control board?
Back to your everyday
Still showing P1?
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.