[{"data":1,"prerenderedAt":187},["ShallowReactive",2],{"doc-\u002Fverticals\u002Flegionella-faq":3},{"id":4,"title":5,"body":6,"description":176,"edit":177,"extension":178,"meta":179,"navigation":180,"path":181,"seo":182,"stem":183,"vertical":184,"weight":185,"__hash__":186},"content\u002Fverticals\u002Flegionella-faq.md","Legionella — frequently asked questions",{"type":7,"value":8,"toc":164},"minimark",[9,14,23,26,30,33,67,70,76,80,87,90,93,97,110,113,121,125,132,143,147,150,153,157],[10,11,13],"h2",{"id":12},"does-temperature-monitoring-replace-the-annual-lab-swab","Does temperature monitoring replace the annual lab swab?",[15,16,17,18,22],"p",{},"No. It ",[19,20,21],"strong",{},"reduces the frequency"," of swabs (in jurisdictions that\nallow that, such as Germany under DVGW W551) but does not replace\nthem. The lab swab confirms there is no Legionella; temperature\nmonitoring evidences that conditions remain unfavourable for growth.",[15,24,25],{},"OpenSense generates a quarterly PDF showing 50\u002F60\u002F50 compliance; most\nEU health authorities accept this as evidence to move from monthly\nto annual sampling. Confirm with your local authority before\ncommitting.",[10,27,29],{"id":28},"where-do-i-install-the-sensors","Where do I install the sensors?",[15,31,32],{},"Five places, in priority order:",[34,35,36,43,49,55,61],"ol",{},[37,38,39,42],"li",{},[19,40,41],{},"Cylinder top"," — top of the hot-water storage tank. The hottest\nlayer. Must be ≥ 60 °C.",[37,44,45,48],{},[19,46,47],{},"Cylinder bottom"," — coldest layer. Where Legionella grows first\nif the heater is undersized.",[37,50,51,54],{},[19,52,53],{},"Ringline return"," — the return loop just before re-entering the\ncylinder. Must be ≥ 50 °C; the diagnostic that the recirc pump\nworks.",[37,56,57,60],{},[19,58,59],{},"Distant outlet"," — the tap farthest from the cylinder. Must\nreach ≥ 50 °C within 30 s of opening.",[37,62,63,66],{},[19,64,65],{},"Cold supply"," — the cold-water inlet. Must be ≤ 25 °C. (Below\nthis temperature Legionella does not thrive.)",[15,68,69],{},"For most small buildings, sensors at positions 1, 2, 3 (storage top",[71,72,73],"ul",{},[37,74,75],{},"bottom + ringline return) are the minimum. Position 4 requires a\nflow-actuated probe; position 5 is cheap and worth adding.",[10,77,79],{"id":78},"how-do-i-install-a-probe-on-a-closed-pipe-without-cutting-it","How do I install a probe on a closed pipe without cutting it?",[15,81,82,83,86],{},"Use a ",[19,84,85],{},"clamp-on PT100"," (the strap-on contact probe with thermal\npaste, wrapped under insulation). Vendor: Sensata, OMEGA, or any\nDIN-rail PT100 transmitter with a contact probe.",[15,88,89],{},"Accuracy is ±1.5 °C against a wet probe in the same line, dominated\nby the quality of the insulation around the contact. For monitoring\nthe 50\u002F60\u002F50 thresholds at ±2 °C precision this is sufficient.",[15,91,92],{},"For high-stakes compliance (a hospital), use a thermowell (cut a\nT-piece into the pipe, install a brass thermowell with thread-seal,\ninsert a PT100 probe in the well). Expensive (€80–€150 per point\ninstalled) but rated for compliance audit.",[10,94,96],{"id":95},"what-about-the-thermal-disinfection-cycle-70-c-nightly","What about the thermal-disinfection cycle (70 °C nightly)?",[15,98,99,100,103,104,109],{},"OpenSense supports a ",[19,101,102],{},"window"," in the rule that raises the\nacceptable temperature during the cycle. See\n",[105,106,108],"a",{"href":107},"\u002Fapi\u002Falerts#time-of-day-windows","Alerts API → time-of-day windows",".",[15,111,112],{},"Be cautious of two things during the cycle:",[71,114,115,118],{},[37,116,117],{},"Some old thermostatic mixing valves (TMVs) cannot tolerate 70 °C\non the supply for an hour. Newer DVGW-certified TMVs can. Check\nyours.",[37,119,120],{},"People in the building can scald themselves at 70 °C taps. If the\ncycle runs while the building is occupied, post warnings.",[10,122,124],{"id":123},"what-is-the-delta-channel","What is the \"delta\" channel?",[15,126,127,131],{},[128,129,130],"code",{},"flow_delta = supply − return",". A healthy ringline has a delta of\n5–10 °C — the loop loses some heat in the run but the return is\nstill > 50 °C. A delta > 15 °C means too much heat is being lost in\nthe loop (broken insulation, oversized pipe) or the pump is too\nsmall for the flow demand. A delta \u003C 3 °C means the pump is too\nstrong — minor concern, but it can mean you are heating more water\nthan the building uses.",[15,133,134,135,138,139,142],{},"OpenSense computes the delta automatically when both ",[128,136,137],{},"flow_supply","\nand ",[128,140,141],{},"flow_return"," channels exist on the same device or same site.",[10,144,146],{"id":145},"a-guest-scalded-themselves-and-is-threatening-to-sue","A guest scalded themselves and is threatening to sue.",[15,148,149],{},"OpenSense's temperature log shows the actual outlet temperature at\nthe time of the incident. If the tap was at 38 °C (you have a TMV)\nthe scald claim is unsustainable; if the tap was at 65 °C (you ran\na disinfection cycle in occupied hours), the log is evidence of\noperator negligence.",[15,151,152],{},"The log cuts both ways. We do not tell you it always saves you. It\nis honest evidence.",[10,154,156],{"id":155},"my-building-manager-says-all-this-is-overkill","My building manager says all this is overkill.",[15,158,159,160,163],{},"For a single-family home, it is. For any building serving the\npublic — hotels, spas, care homes, hospitals, schools, dormitories,\ngyms, public swimming pools — Legionella is ",[19,161,162],{},"the"," waterborne risk.\nPeriodic outbreaks happen in EU buildings; insurance and statute now\nrequire demonstrable management. OpenSense is one component of that\nmanagement; an annual risk assessment by a competent person and a\nwritten water-safety plan are the others.",{"title":165,"searchDepth":166,"depth":166,"links":167},"",3,[168,170,171,172,173,174,175],{"id":12,"depth":169,"text":13},2,{"id":28,"depth":169,"text":29},{"id":78,"depth":169,"text":79},{"id":95,"depth":169,"text":96},{"id":123,"depth":169,"text":124},{"id":145,"depth":169,"text":146},{"id":155,"depth":169,"text":156},"Hotel \u002F care home \u002F spa operator perspective",null,"md",{},true,"\u002Fverticals\u002Flegionella-faq",{"title":5,"description":176},"verticals\u002Flegionella-faq","legionella",321,"o3m6s_umoeLE24Z1j6ZdlDt8OOrtD07QWEOo5QM51kQ",1779022954927]