Alpha [E38] fault codewhat it means and how to fix it

Alpha call this loss of flame rectification, and their description is "flame detected but signal lost, ignition retries after fan purge". Two things follow from that. The first is the separation from E01, which is the code people confuse it with: in an E01 the appliance never established a flame at all, while here it did — ignition worked, the flame was proved, the burner ran — and then the signal went. That eliminates a family of causes outright. The electrode evidently fired, and there was gas at the burner at the moment of lighting.

So the question is what changed during the cycle: a gas supply that sags under load rather than being absent, condensate backing up as soon as the appliance starts producing it, a flue recirculating its own products once it warms, or a sensing electrode losing its grip on a marginal signal as the chamber heats and metal moves. The second is a quirk of Alpha's own numbering that will mislead you if you do not know it.

Alpha publish two separate faults under the loss of flame rectification heading — this one, and a different code covering repeated loss of flame signal during operation, which they say can occur when the flue is exposed to high wind. They then note that the second one is "shown as E38 in the fault code history in the INFO menu". So an E38 read off the d9 history is not necessarily the E38 that was on the display, and if yours appears in windy weather on an exposed terminal, the wind explanation is the more likely of the two despite the number.

1. 1

   Time it. Note how long the appliance runs before the code appears, over two or three attempts. A consistent interval points at condensate; a random one points at gas supply or wind.

2. 2

   Check whether it fails more readily when another gas appliance is running, such as a hob at full rate. If so, the supply is the likely constraint and that is a job for an engineer with a manometer.

3. 3

   In cold weather, check the external condensate pipe for ice as you would for an ignition lockout, and thaw it with warm water if you find any.

4. 4

   Note whether it is worse on windy days. That is genuinely useful diagnostic information and it is the kind of thing only the household can observe.

5. 5

   Reset no more than twice. Give whoever attends the timing pattern you noted — it will save them a visit.