A flooded BlitzWolf BW-SS1 WiFi smart relay switch was recovered from silt, dried for months, and inspected after a flood on 15 September.
Inside, a PN8016 non-isolated step-down converter feeds an LDO for 3.3V, while the LM2 WiFi module drives the relay; the reset button showed the most corrosion.
The unit was extracted on 27 September and tested again on 11 April, after roughly six months of drying.
After cleaning with isopropyl alcohol and flashing Tasmota, the access point appeared, the BW-SS1 template loaded, and both LEDs still worked.
Long-term reliability is still uncertain, and the screw terminals may need filing to restore good contact.
Generated by the language model.
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Today I am going to check the condition of a small electronic gadget flooded. The flood took place on 15 September and I extracted the equipment from the silt on 27 September, about two weeks later. The water carried so much sand and soil that I had to play archaeologist, and the water level is indicated by the line on the light:
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Now let's see the relay itself. The sand has essentially dried up:
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The shape of the RESET button has rebounded:
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The victim itself is the WiFi-controlled BW-SS1 relay working with the BlitzWolf app.
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First section:
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I then took the equipment out to dry and wait, it's been about six months. It is now 11 April.
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The operation of the device itself is very simple - here we have a non-isolated step-down converter based on a PN8016 and then there is just an LDO regulator providing 3.3V for the WiFi module, and this module in turn controls the relay.
It looks like the button has suffered the most - you can see corrosion on it. I cleaned the board with isopropyl alcohol. I also soldered out the LM2 WiFi module:
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I removed the screen with hot air:
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No damage is apparent, so it's time to upload Tasmota and see if WiFi works:
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Uploading Tasmota:
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There is an access point:
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The BW-SS1 template has been successfully uploaded:
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It looks like everything is working, but whether the situation will continue, time will tell.
In summary , this was a loose topic - a curiosity. In the end it worked out that it paid off to leave the module in place. Even both LEDs are working. Now it remains to run a file over the screw terminals to make sure there is good contact.
Of course, this is not the end of the experiments, as I have more flooded equipment - for example, I have tiles left over from flooded Alfawise air purifiers:
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In the next part I will also check the WiFi modules from these boards. I'll see if they're still suitable for some DIY or if, however, in this case the humidity has won out....
Of the thicker hardware I have, among other things, a switch for presentation:
Spoiler:
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... But in his case the story will be short, because he was also damaged before the flooding.
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TL;DR: After about 6 months of drying, a BlitzWolf BW-SS1 buried in silt for about 2 weeks still worked; "everything is working" after cleaning, LM2 inspection, Tasmota flashing, and a final relay test. This FAQ helps repair-minded owners decide whether a flood-damaged smart switch is recoverable and how to verify it. [#21516100]
Why it matters: Flood damage can leave a smart switch functional at first power-up, while corrosion still threatens its long-term reliability.
Option
Evidence in the thread
Post-flood result
Original BlitzWolf app
BW-SS1 originally worked with the BlitzWolf app
Not used for the recovery verification
Tasmota
Flashed onto the LM2 module; BW-SS1 template imported
Access point appeared and the final relay test worked
Key insight: Drying alone was not the whole fix. Cleaning corrosion, checking the LM2 module, and validating GPIO mapping with Tasmota turned a buried flood-damaged relay into a working test unit.
Quick Facts
The flood happened on 15 September, and the BW-SS1 was recovered from silt on 27 September, about 2 weeks later. [#21516100]
The device then dried for about 6 months and was retested on 11 April. [#21516100]
Its power chain uses a PN8016 non-isolated step-down stage and an LDO regulator that supplies 3.3 V to the LM2 WiFi module. [#21516100]
The most visible corrosion appeared on the tactile RESET button, while the LM2 module showed no obvious internal damage after shield removal. [#21516100]
After cleaning with isopropyl alcohol and flashing Tasmota, the switch exposed an access point, accepted the BW-SS1 template, and even both LEDs still worked. [#21516100]
How do you clean and revive a flood-damaged BlitzWolf BW-SS1 smart switch after it has been buried in silt for weeks?
You revive it by drying, cleaning, and then testing each function in stages. 1. Recover the unit, remove dried sand and soil, and let it dry fully; this sample sat about 6 months after roughly 2 weeks in silt. 2. Clean the PCB with isopropyl alcohol and inspect corrosion, especially around the RESET button. 3. Check the LM2 WiFi module, reassemble, and verify WiFi, LEDs, and relay operation before trusting it again. [#21516100]
What steps are involved in flashing Tasmota onto the LM2 WiFi module used in the BlitzWolf BW-SS1?
The thread shows a short recovery workflow, not a full programming guide. 1. Desolder the LM2 WiFi module from the BW-SS1 board. 2. Remove the metal shield with hot air and inspect for visible damage. 3. Upload Tasmota, confirm that an access point appears, and then import the BW-SS1 template so the GPIO mapping matches the hardware. [#21516100]
Why would a flooded BW-SS1 still work after six months of drying, and which parts are most likely to fail first?
It can still work because the core electronics showed no obvious damage after drying and cleaning. In this case, the LM2 module still accepted Tasmota, created an access point, and drove the relay. The tactile RESET button looked worst, with visible corrosion, so switches and exposed contacts are the first likely failure points. Screw terminals also remained suspect because the author still planned to file them for better contact. [#21516100]
What is a non-isolated step-down converter, and how does the PN8016 use it in a smart relay like the BW-SS1?
"Non-isolated step-down converter" is a power-supply stage that lowers mains voltage without galvanic isolation, keeping the low-voltage side electrically tied to the input side. In the BW-SS1, the PN8016 performs that first reduction before the local 3.3 V supply stage feeds the control electronics. The thread describes this as the first block in the relay’s simple power path. [#21516100]
What is an LDO regulator, and why does the BW-SS1 need 3.3V for its WiFi module?
"LDO regulator" is a linear voltage regulator that provides a stable low output voltage from a slightly higher input, with simple, low-noise operation. In the BW-SS1, it delivers 3.3 V so the LM2 WiFi module can run after the PN8016 drops the mains-derived voltage. The thread explicitly states that the LDO supplies 3.3 V for the WiFi section. [#21516100]
Which symptoms of corrosion on a tactile RESET button mean it should be cleaned versus replaced?
Clean the button if corrosion is visible but the switch body still holds shape and the unit remains testable. In this BW-SS1, the RESET button shape had rebounded, yet corrosion was visible, so the board was cleaned and the device still worked afterward. Replace the button if corrosion prevents consistent action or the switch no longer supports reliable testing, because this part looked most affected in the thread. [#21516100]
How should you safely test a flood-damaged mains-powered smart switch before reconnecting it to household wiring?
Test it in stages and do not trust it immediately after drying. First dry it thoroughly; this unit waited about 6 months. Next clean the PCB with isopropyl alcohol, inspect corrosion, and check the LM2 module. Then verify low-level functions first, such as Tasmota flashing, access-point creation, LEDs, and relay response, before considering household use. The thread also flags the screw terminals as a final contact-risk area. [#21516100]
What is the BW-SS1 Tasmota template, and how do you import the correct GPIO configuration?
The BW-SS1 Tasmota template is the JSON device profile that maps the relay’s GPIO functions correctly. In the thread, the uploaded template was {“NAME”:“BW-SS1”,“GPIO”:[255,255,255,255,157,21,0,0,255,17,255,255,0],“FLAG”:0,“BASE”:18}. The practical sequence was simple: flash Tasmota, confirm the access point appears, and then upload this BW-SS1 template so the hardware works with the right pin assignments. [#21516100]
Why is isopropyl alcohol used to clean flooded electronics boards, and when is it not enough on its own?
It is used here as the board-cleaning step after flood exposure and dried contamination. The author cleaned the BW-SS1 PCB with isopropyl alcohol before deeper testing, which helped remove residue around corroded areas. It is not enough on its own when dirt has packed into mechanical parts or contacts, because this unit still needed LM2 inspection and the screw terminals still needed filing for dependable electrical contact. [#21516100]
How do you remove the metal shield from an LM2 WiFi module with hot air without damaging the board?
Use hot air only to lift the shield, then inspect immediately for visible damage. The thread reports that the LM2 shield was removed with hot air and no damage was apparent underneath. That outcome matters because the next step was successful Tasmota flashing and access-point creation, which confirmed the WiFi section survived the flood and the shield-removal process. [#21516100]
BW-SS1 with the original BlitzWolf app vs Tasmota — which is better after restoring a flood-damaged device?
Tasmota was better for post-flood verification in this case. The original device had worked with the BlitzWolf app before flooding, but the recovery test used Tasmota instead. Tasmota gave two concrete checks: the LM2 module created an access point, and the BW-SS1 template loaded successfully. Those results made it a stronger diagnostic choice for a restored unit than the untested original app path. [#21516100]
What long-term problems can appear in a smart relay after flood exposure even if the WiFi, relay, and LEDs still work during the first test?
Corrosion can keep progressing after the first successful power-up. The thread already showed corrosion on the RESET button and uncertainty about whether the good result would continue over time. The author also still planned to file the screw terminals to ensure good contact, which means exposed electrical joints remained a long-term risk even though WiFi, relay action, and both LEDs initially worked. [#21516100]
How do you check whether the screw terminals on a recovered BW-SS1 still make reliable electrical contact after corrosion and dirt exposure?
Inspect and mechanically refresh the terminals before trusting them. The thread’s next planned step was to run a file over the screw terminals to make sure contact was good, which shows that visual survival is not enough after mud and corrosion. If the metal surfaces remain dirty or oxidized after cleaning, contact resistance can stay unstable even when the relay, LEDs, and WiFi already pass a first test. [#21516100]
What troubleshooting steps help when a restored LM2-based smart switch creates a Tasmota access point but behaves unreliably afterward?
Recheck the hardware first, then the template. Confirm the PCB is clean, revisit corrosion around the RESET button, and inspect the LM2 module area again if you removed the shield. Then verify that the BW-SS1 template loaded correctly, because the thread used a specific GPIO map after the access point appeared. Finally, retest relay action and both LEDs, since those were the author’s practical proof points. [#21516100]
How can you evaluate whether WiFi modules recovered from flooded Alfawise air purifier boards are still useful for DIY projects?
Use the BW-SS1 process as the screening method. The thread says the next step is to check the WiFi modules from flooded Alfawise purifier boards and see whether they are still suitable for DIY or whether humidity has won. A practical evaluation sequence is clear from the post: dry the boards, inspect for corrosion, clean contamination, expose the module if needed, and then test whether the WiFi section still behaves normally. [#21516100]
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