Grant Aerona E58 fault code

What it means

Gas sensor fault

The R290 leak sensor is reporting a fault. Grant's table names it simply 'GAS SENSOR' and gives the same wiring / Refrigerant PCB remedy as E57. Treat any accompanying alarm as a real leak until you have disproved it with your own detector.

Safety: R290 is propane — flammable (A3), and Grant's manual states it is ODOURLESS, so a leak will not be noticed by smell. With this code active the unit's own leak detection cannot be relied on, so your detector is the only one working. Survey before AND during work with equipment suitable for flammable refrigerants — non-sparking, adequately sealed or intrinsically safe, calibrated in a refrigerant-free area. Never use a halide torch or any naked-flame detector. No ignition sources, ventilate, and have dry-powder or CO₂ extinguishing equipment to hand for any hot work.

UK models this code applies to

From the Grant service literature we hold (Grant Aerona 290 installation manual DOC0204 Rev 1.8, Table 11-1 (p.57); safety steps from §10.6 and the flammable-refrigerant work procedure) — not a scraped list.

Now the harder half: proving what caused it

E58 names a symptom, not a root cause. In the app, the same code opens a guided investigation: what to measure first, the expected values for your exact model, and an honest verdict — including “nothing in this machine is broken” when that's what the readings say.