If your Daikin VRV system is showing error code E3, the high pressure switch activated and the system shut itself down.
That shutdown did its job. It protected your compressor. But the reason pressure climbed is still there, and it will happen again on the next attempt.
What this means for your building
A VRV system rejects heat through the outdoor unit. When something interferes with that process, pressure on the high side rises.
At a defined limit, the high pressure switch opens and the system stops rather than allow pressure to keep climbing.
The critical framing: E3 is a symptom, not a diagnosis. It tells you pressure got too high. It does not tell you why, and the reasons range from a straightforward cleaning to a significant repair.
How urgent is it?
Urgent, though not hazardous. Nothing is escaping and nobody is at risk.
The urgency is about the compressor. Compressors rarely fail suddenly — they fail after being run repeatedly outside their design envelope. A system throwing E3 that gets reset and run again is a compressor being worn out deliberately.
What it typically costs
Medium to high, with one of the widest ranges on the Daikin list.
At the cheap end, a blocked outdoor coil is a cleaning. In the middle, a failed outdoor fan motor or a refrigerant charge correction. Toward the upper end, evacuating non-condensables means recovering and recharging the system properly.
The genuinely expensive outcome is what E3 leads to when ignored: compressor damage.
What causes it
- Blocked or dirty outdoor coil — the most common, and the cheapest to resolve
- Outdoor fan motor failure or restriction — if the fan is not moving air, heat is not leaving. This often shows as E7 alongside.
- Airflow obstruction around the unit — debris, added screening, storage, or equipment installed too close
- Refrigerant overcharge — frequently from a previous service where charge was added instead of a leak being repaired
- Non-condensables in the system — air introduced during a repair where the system was not properly evacuated
- High ambient conditions compounding any of the above
Two of those trace directly back to previous service work. Overcharge and non-condensables are both artefacts of a repair done quickly rather than correctly, and they are more common than most building owners realise.
What happens if you leave it
Short term, the affected system stops and your tenants notice.
Long term is where the money is. Each high pressure event stresses the compressor. Repeated events accumulate wear that does not become visible until the compressor fails — at which point you are looking at the largest repair on the system.
A dirty coil caught in spring is a cleaning. The same coil ignored through a Los Angeles summer can be a compressor.
What we check
- Inspect the outdoor coil for blockage, and the surrounding space for airflow restriction.
- Verify outdoor fan operation — running, correct speed, unobstructed. A failing fan frequently shows up here before it raises its own code.
- Measure system pressures to establish where the system actually sits.
- Assess refrigerant charge — overcharge as well as undercharge.
- Check for non-condensables, particularly if the system has been serviced recently.
- Verify the high pressure switch and sensors — occasionally the reading is wrong rather than the pressure.
- Review fault history to establish how long this has been developing.
What you can tell us before we arrive
- Does it only trip in hot weather? Strongly suggests a marginal heat rejection problem.
- Has the system been serviced recently? Overcharge and non-condensables both originate in prior work.
- How many times has it tripped? A first occurrence and a recurring pattern are different situations.
- Has anything been built or stored near the outdoor unit? Screening and storage restrict airflow more than people expect.
Related codes
- E7 — Outdoor fan motor fault. A frequent cause of high pressure, and often present alongside.
- E4 — Low pressure sensor activation. The opposite condition.
- L5 / L8 — Compressor faults. Where repeated E3 events eventually lead.
Diagnose it while it is still the cheap repair
We are certified on Daikin, Mitsubishi and LG VRF platforms, and we service systems we did not install.
Next business day service for commercial VRF.
Related codes
Error E7 is an outdoor fan motor fault. Extremely common on commercial rooftops, and it cascades into pressure and compressor problems if left running.
Error L8 is sustained compressor overcurrent. Unlike L5, it often means the system is working too hard against an external condition.
Error E4 means low pressure protection activated. On commercial VRV it often points at a failed expansion valve or a restriction rather than a simple leak.
Frequently asked questions
What does error code E3 mean on a Daikin VRV system?
The high pressure switch activated and the system shut down. Refrigerant pressure on the high side exceeded its safe limit, which means something is preventing the system from rejecting heat properly. The shutdown is protection, not the fault itself.
What causes high pressure on a commercial VRV system?
Most often blocked or dirty outdoor coils, a failed or restricted outdoor fan, or airflow obstruction around the unit. Refrigerant overcharge and non-condensables introduced during previous service work are also common, particularly on systems that have been repaired before.
What are non-condensables and why do they cause E3?
Non-condensables are gases such as air that do not condense in the refrigerant circuit. They usually enter during a repair where the system was not properly evacuated. They occupy space and raise pressure, and the only fix is to evacuate and recharge correctly.
Why does E3 only appear on hot days?
Ambient heat adds to the load the system is already working against. A marginal fault such as a partially blocked coil can be tolerable in mild weather and trip protection once outdoor temperature rises. A fault that appears only in heat is still a real fault.
Can I keep resetting an E3 error?
You can reset it, but the condition causing it has not changed, so it will trip again. Each cycle runs the compressor under excessive pressure. Repeatedly resetting E3 is one of the most common ways an inexpensive repair becomes a compressor replacement.
How much does an E3 error cost to fix?
Medium to high, with wide range depending on cause. A dirty outdoor coil is a cleaning. A failed fan motor, a charge correction, or evacuating non-condensables are progressively more involved. The expensive outcome is the compressor damage that follows if it is ignored.