Dometic Air Conditioner Symbols and What They Mean

Dometic air conditioner symbols can be confusing the first time you see them in a caravan or RV. You are set up at a site, it is hot, and the little screen on the air distribution box is showing something you have never seen before. The manual is in the van somewhere, or it went missing three trips ago.

Dometic rooftop air conditioners use a different set of symbols to a house split system, and a few of them behave in ways that look like faults and are not. This page sets out every symbol on a Dometic remote and control panel in plain language, taken from Dometic operating manuals rather than from guesswork.

Dometic air conditioner symbols at a glance

Here is the quick answer. Dometic fits different controls across the FreshJet, Ibis and Harrier ranges, so if something on yours is not listed, check the sections below on error codes and on the older status light. If you are looking for a house system instead, our general guide to air conditioner symbols covers those.

The six Dometic modes and what each one does

Dometic uses six modes rather than the usual five, because air purifier sits alongside the others.

Fan speed and the numbers on the display

Dometic uses five fan levels rather than the usual three. They are low, medium, high, turbo and auto.

On the air distribution box display these show as numbers instead of words. 1 is low, 2 is medium, 3 is high, 4 is turbo, and AA is auto. On auto the unit adjusts the speed based on the ambient temperature.

Turbo is worth using deliberately. On the Ibis it has its own button, and pressing it again returns the fan to whatever it was doing before. Use it to pull the heat out of a van that has been sitting in the sun, then drop it back rather than leaving it on.

Remember that fan speed cannot be chosen by hand in automatic or dehumidifying modes. The unit takes that decision in both.

Sleep, timer and I feel

What is not on a Dometic, and why that matters

Two symbols people go looking for are not there, and it is worth saying so plainly rather than letting you hunt.

• There is no child lock or keypad lock symbol. Dometic does not document one in the current FreshJet operating manuals. If your buttons have stopped responding, it is not a lock.
• There is no wifi or bluetooth icon with a published meaning. Dometic documents the pairing action, where two buttons are pressed together to pair with bluetooth or wireless, and lists connectivity on the FreshJet range, but it does not publish a display icon for it. The only transmission symbol Dometic defines is the one showing the remote sending values to the roof unit.

A lot of pages about Dometic symbols list a padlock anyway, copied across from house split systems. It is not in the Dometic documentation.

Dometic error codes and what they mean

Newer Dometic units, including the FreshJet, Ibis and Harrier inverter platforms, show a two character code on the display when something is wrong.

P1 is the one caravanners see most, and Dometic gives a very practical remedy for it. Check with the campsite management whether the voltage at the site is sufficient. It is a power supply problem, not an air conditioner problem.

The status light on older FreshJet units

If your unit shows no codes but has a single status light, it is an earlier FreshJet and the light itself is the message. Dometic publishes the following for that generation.

Note that a flashing green light on these older units is normal behaviour during defrost or heat preparation, not a fault. Winter mode is also documented, starting at a temperature of 7 degrees and stopping once the temperature rises above 10.

Do not apply this light table to a newer FreshJet or a Harrier. Those units have no light colour table at all and report faults as a code on the display instead.

Operating limits worth knowing before you call anyone

A lot of Dometic call outs are the unit obeying a published limit.

• Set temperature range. 16 to 31 degrees in automatic, cooling, heating and dehumidifying.
• Ambient range. Dometic gives an operating range of minus 2 degrees up to 52 degrees.
• No cooling below 16 degrees outside. Stated plainly in the manual.
• No cooling above 52 degrees outside. Listed as a cause of no cooling.
• No heating below minus 2 degrees. Also stated.
• Low voltage. Below about 200 volts the unit protects itself and shows P1.
• High voltage. Above 265 volts the unit stops, and resumes once the supply is back in range.
• Supply. 220 to 240 volts at 50 hertz.

One thing this page will not tell you, because Dometic does not publish it. There is no documented wait time before switching a Dometic back on after shutting it down. The three minute rule you may have read elsewhere comes from house split systems and is not in the Dometic manuals.

Running a Dometic from a generator

This comes up constantly and Dometic answers it directly.

The generator must be correctly sized for the model, and the installation manual carries the requirement for each unit. Dometic states the generator should have pure sine wave output. Starting also needs either a hard start capacitor, which some models include, or a soft start device.

On models with soft start built in, Dometic describes the function as reducing the peak current the compressor start produces, so that a generator used as the power supply will not be overloaded.

Dometic does not publish a generator wattage figure on its support pages, so treat any specific number you find elsewhere with caution and check the installation manual for your model.

Why will my Dometic air conditioner not switch on?

Work through these before assuming a fault.

1. Point the remote at the air outlet unit display. Dometic gives this as the first remedy, and it is a line of sight device.
2. Check the remote battery symbol. A flat remote looks exactly like a dead air conditioner.
3. Check the site power. If the supply is weak the unit will protect itself and show P1.
4. Check the mode. In ventilation the unit runs but does nothing to the temperature.
5. If you are in heating, wait. The fan does not start for about two minutes by design.
6. If it is a mechanical model, remember there is no remote at all. Dometic states the remote control is unavailable for mechanical models, which use knobs on the panel instead.

What the remote does that the panel does not

The two controls are not interchangeable, and knowing which does what saves a lot of hunting.

Remote only. Timer programming, the I feel function, turning sleep on and off, and the display of the actual room temperature, the time and the battery status.

Panel only. The external lights on inverter models, cycling the internal light brightness, and pairing with bluetooth or wireless.

Which Dometic symbols point at a real fault?

Most of what is on the screen describes a setting. A few things are worth treating differently.

• Any code beginning with E that does not clear after a power cycle. These are sensor, communication and drive faults.
• P9, which means the compressor drive is abnormal or the compressor will not start.
• A code that returns every time you run the unit even with good site power.
• Water inside the van around the air distribution box, which usually means a drain or a seal rather than the air conditioner itself.
• The unit runs but never gets the van near the set temperature on a day well inside the published ambient range.

P1 on a powered site is worth one conversation with the site office before it is worth a technician.

Getting your Dometic back to doing its job

Most symbols on a Dometic are the unit telling you what it has been asked to do, or reporting a limit it has run into. Snowflake, droplet, a number for the fan, and a code when something is genuinely wrong.

Read the chart at the top of this page, match what is on your screen, and in most cases the answer is a button press or a word with the site office. Worth knowing too is how often you should service your air conditioner, because a rooftop unit collects dust faster than a house system does.

When the symbols all look right and the van still will not cool, that is the point where guessing costs more than asking. We send a licensed technician who works on air conditioning across Melbourne, and the price is confirmed before any work starts.

If the unit is doing nothing at all rather than showing an unfamiliar symbol, start with our guide on an air conditioner not working instead.

If the same symbols turn up on the split system at home, our air conditioner service in Melbourne covers those, and you can request a quote in a couple of minutes.