{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.instantaneous-water-heater","code":"thing-q5953359","url":"https://ver.cy/models/thing/q5953359/","name":"instantaneous water heater","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.OBJ"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"An instantaneous water heater is a device that heats water as it flows through the device, using an electric heating element or fuel-fired heat exchanger rather than maintaining a tank of stored hot water.","purpose":"Enable an AI agent to recognise an instantaneous water heater, assess its ability to meet a hot-water demand, and determine which operating or service actions its condition permits.","scope":{"in":["Flow-through heating principle and distinction from storage-based water heating","Electric or fuel-fired heating arrangements and their supply requirements","Delivered temperature and flow under specified inlet and demand conditions","Flow activation, heat modulation, operating states and protective shutdowns","Appliance water connections, installation constraints and service needs","Evidence of applicable conformity, commissioning and maintenance"],"out":["Manufacturer product lines and individual appliance records as separate catalogue concepts","Building-wide hot-water distribution, circulation and storage systems","Upstream electricity, fuel and water supply infrastructure","Space-heating boilers except the instantaneous domestic-water function of a combined appliance","Fixture mixing valves and outlet fittings except their interfaces with the heater","Detailed installation procedures belonging to the applicable product manual and local requirements"],"boundaries":[]},"distinguishingFeatures":["Its primary hot-water production heats a moving water stream instead of drawing principally from a maintained reservoir of hot water.","Its ability to meet demand must be assessed using flow rate and inlet-to-outlet temperature rise together, rather than storage volume alone.","A hot-water demand initiates or enables heating through the appliance's demand-detection arrangement; the activation threshold must be established for the design.","It adds heat to water rather than merely mixing, circulating or dispensing water heated elsewhere.","Its defining output is heated water; an instantaneous domestic-water section within a combined boiler must be distinguished from the boiler's space-heating function."],"structure":{"bundles":[{"id":"flow-through-identity","name":"Flow-through identity","description":"Establishes what makes the appliance instantaneous and where its function begins and ends.","layers":[{"id":"heating-path","name":"Heating path","description":"Identifies how incoming water acquires heat while passing through the appliance.","findings":[{"id":"primary-production-mechanism","name":"Primary production mechanism","description":"Record evidence that flow-through heat addition is the primary production method, including any auxiliary retained water.","questions":[{"text":"What component transfers heat to the flowing water, and what energy source supplies it?","id":"primary-production-mechanism-q01","kind":"definition"},{"text":"Does any internal reservoir primarily supply stored hot water or serve an auxiliary buffering function?","id":"primary-production-mechanism-q02","kind":"boundary"}]}]},{"id":"appliance-boundary","name":"Appliance boundary","description":"Separates the heater's function from connected fixtures and other heating functions.","findings":[{"id":"standalone-and-combined-functions","name":"Standalone and combined functions","description":"Identify whether instantaneous water heating belongs to a dedicated appliance or an identifiable section of a combined device.","questions":[{"text":"Is this a dedicated water heater, an integrated heated fixture or the domestic-water section of a combined appliance?","id":"standalone-and-combined-functions-q01","kind":"boundary"},{"text":"Which diagram or manufacturer description establishes the heater's inlet, outlet and included control components?","id":"standalone-and-combined-functions-q02","kind":"provenance"}]}]}]},{"id":"hot-water-delivery-envelope","name":"Hot-water delivery envelope","description":"Relates useful heat output to inlet conditions, water flow and requested outlet temperature.","layers":[{"id":"thermal-capacity","name":"Thermal capacity","description":"Makes performance claims conditional on the water and energy conditions under which they apply.","findings":[{"id":"flow-temperature-capacity","name":"Flow and temperature capacity","description":"Record delivery points or curves with their test conditions rather than treating a maximum flow claim as universal.","questions":[{"text":"At what inlet temperature, temperature rise and supply conditions is each stated delivery flow achieved?","id":"flow-temperature-capacity-q01","kind":"measurement"},{"text":"Can the documented useful output meet the intended simultaneous outlet demand at the lowest expected inlet temperature?","id":"flow-temperature-capacity-q02","kind":"action"}]}]},{"id":"activation-and-transients","name":"Activation and transients","description":"Captures behaviour at low flow, startup and changing demand.","findings":[{"id":"minimum-demand-and-temperature-response","name":"Minimum demand and temperature response","description":"Identify activation thresholds and distinguish appliance temperature response from delivery delays in downstream pipework.","questions":[{"text":"What flow starts heating, what flow sustains it, and under which conditions were those thresholds established?","id":"minimum-demand-and-temperature-response-q01","kind":"measurement"},{"text":"When temperature varies after startup or a demand change, which part of the response originates inside the heater and which in the distribution system?","id":"minimum-demand-and-temperature-response-q02","kind":"boundary"}]}]}]},{"id":"demand-control-and-protection","name":"Demand control and protection","description":"Describes how the heater recognises demand, regulates heat and responds to unsafe or abnormal conditions.","layers":[{"id":"heat-regulation","name":"Heat regulation","description":"Connects sensed demand and temperature to the appliance's available heat-control actions.","findings":[{"id":"demand-to-heat-control","name":"Demand-to-heat control","description":"Record demand sensing, user settings and modulation or staging without assuming every heater maintains a selected temperature.","questions":[{"text":"Which flow, pressure or temperature signals enable heating and determine its intensity?","id":"demand-to-heat-control-q01","kind":"definition"},{"text":"Which documented user adjustments can address the observed delivery problem within the appliance's operating limits?","id":"demand-to-heat-control-q02","kind":"action"}]}]},{"id":"protective-states","name":"Protective states","description":"Identifies installed safeguards and the conditions for shutdown, reset or service.","findings":[{"id":"protection-and-restart-evidence","name":"Protection and restart evidence","description":"Record applicable protections, such as overtemperature, inadequate water flow, electrical faults or combustion failure, only where supported for the design.","questions":[{"text":"Which protective devices are documented, and which observed indication identifies the active shutdown or lockout?","id":"protection-and-restart-evidence-q01","kind":"provenance"},{"text":"What documented conditions must be satisfied before a user reset, qualified service intervention or return to operation is permitted?","id":"protection-and-restart-evidence-q02","kind":"action"}]}]}]},{"id":"installation-and-conformity","name":"Installation and conformity","description":"Connects the heater's water and energy interfaces to evidence that an intended installation is compatible.","layers":[{"id":"water-and-energy-interfaces","name":"Water and energy interfaces","description":"Records supply and connection constraints specific to the heater configuration.","findings":[{"id":"connection-compatibility","name":"Connection compatibility","description":"Establish required water pressure, outlet arrangement and energy supply, including combustion interfaces where relevant.","questions":[{"text":"Is the appliance intended for an open-outlet or closed-outlet installation, and what connected fittings or restrictions does its manual permit?","id":"connection-compatibility-q01","kind":"boundary"},{"text":"Do measured water and energy supply conditions satisfy the documented requirements under heating demand?","id":"connection-compatibility-q02","kind":"measurement"},{"text":"For a fuel-fired design, what evidence establishes compatibility of the installation location, combustion-air provision, exhaust route and any condensate connection?","id":"connection-compatibility-q03","kind":"provenance"}]}]},{"id":"applicability-and-commissioning","name":"Applicability and commissioning","description":"Ties standards, marks and installation checks to a specific appliance class and jurisdiction.","findings":[{"id":"verified-installation-basis","name":"Verified installation basis","description":"Require traceable applicability evidence rather than assuming that a familiar mark or standard covers every instantaneous heater.","questions":[{"text":"Which standards and issuing bodies apply to this energy source, appliance class and jurisdiction, and what edition or effective date is relevant?","id":"verified-installation-basis-q01","kind":"provenance"},{"text":"Which product documents support any claimed certification or conformity mark, and what does that evidence cover?","id":"verified-installation-basis-q02","kind":"provenance"},{"text":"Which commissioning checks remain necessary before this installation can be treated as ready for use?","id":"verified-installation-basis-q03","kind":"action"}]}]}]},{"id":"water-path-condition-and-service","name":"Water-path condition and service","description":"Relates heat-transfer and flow-path condition to performance loss and permitted maintenance.","layers":[{"id":"degradation-diagnosis","name":"Degradation diagnosis","description":"Separates capacity limitations from changes in the heater's condition.","findings":[{"id":"delivery-loss-evidence","name":"Delivery loss evidence","description":"Compare current flow, temperature and fault observations with documented or previously measured behaviour before attributing a cause.","questions":[{"text":"How have inlet pressure, water flow, temperature rise and fault indications changed under comparable demand conditions?","id":"delivery-loss-evidence-q01","kind":"measurement"},{"text":"What inspection or service evidence supports scale, an obstructed inlet filter, corrosion or a control fault as the cause?","id":"delivery-loss-evidence-q02","kind":"provenance"}]}]},{"id":"service-and-seasonal-exposure","name":"Service and seasonal exposure","description":"Captures approved cleaning, component service and protection during freezing conditions or extended disuse.","findings":[{"id":"permitted-service-and-preservation","name":"Permitted service and preservation","description":"Link maintenance and preservation actions to the applicable manual, water conditions and dependencies of any installed freeze protection.","questions":[{"text":"What cleaning or descaling method, consumables and service criteria does the manufacturer permit for this water path?","id":"permitted-service-and-preservation-q01","kind":"action"},{"text":"What draining or freeze-protection provisions apply, and which rely on continued electricity, fuel or other installation conditions?","id":"permitted-service-and-preservation-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these standards and regulation hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-regional-variation","name":"Regional variation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these regional variation hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-regional-variation-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of instantaneous water heater this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Monitor flow, temperature and faults on a heater it is authorised to manage.","Set outlet temperature within safe limits chosen by the household.","Remind the user of servicing and descaling needs."],"mustNot":["Raise outlet temperature to a level that can scald, especially where children or older people bathe.","Disable temperature limiters, flame safeguards or earth protection.","Install or repair gas or mains electrical connections without a qualified person.","Run a gas heater in a room without the ventilation or flue it requires."],"requiresHuman":["Any work on gas supply, flue or fixed electrical wiring."]},"ethics":{"considerations":["Hot water safety matters most for the people least able to react to scalding."],"affectedParties":["Household members","Installers and service technicians","Neighbours in shared buildings"]},"owners":{"steward":"The owner of the property; registered installers answer for safe installation.","roles":[],"masterSystems":[]},"relations":[{"target":"Q16630809","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.instantaneous-water-heater","Wikidata: Q5953359 (https://www.wikidata.org/wiki/Q5953359)"]},"properties":{"applicability":"required","items":["Heating energy source: Electric resistance; specified fuel-fired type; other documented mechanism","Rated input and useful heating output: kW, recording input and output separately with rating conditions","Water temperature rise: K, with inlet temperature, outlet temperature and water flow in L/min","Heating activation and sustaining flow: L/min for activation and continued heating, separately where specified","Temperature regulation method: Fixed or staged heat input; modulating temperature control; other documented arrangement","Permitted water pressure: kPa or bar, distinguishing operating limits and test conditions","Water-side connection arrangement: Closed-outlet pressure-rated; open-outlet or vented; other documented arrangement","Electrical or fuel supply requirements: Required supply specification, including applicable voltage, phase, current, fuel type and fuel pressure","Combustion air and exhaust arrangement: Documented intake, exhaust and indoor or outdoor installation classification; not applicable to non-combustion types","Operating and protection state: Idle; demand detected; heating; capacity-limited; protective shutdown; fault lockout; isolated; unknown","Water quality compatibility: Manufacturer limits linked to measured hardness and other specified water properties","Physical installation envelope: Dimensions and required clearances in mm; mass in kg; specified mounting orientation"]},"recognition":{"applicability":"required","items":["A compact wall-mounted unit near the point of use, without a storage tank.","Gas models have a flue outlet; electric models have a heavy-duty supply cable."]},"capabilities":{"applicability":"required","items":["Classify a candidate appliance as instantaneous, storage-based or a combined arrangement using documented operating evidence.","Compare a required flow and temperature rise with the appliance's documented delivery envelope.","Check compatibility with water pressure, supply capacity, connected outlets and applicable exhaust arrangements.","Interpret low-flow cycling, temperature shortfall and protective shutdown using observed conditions and documented controls.","Identify permissible user adjustments and distinguish them from installation or service actions requiring qualified personnel.","Assemble missing commissioning, conformity and maintenance evidence before recommending operation or return to service."]},"hazards":{"applicability":"required","items":["Scalding from excessive outlet temperature.","Carbon monoxide from poorly vented gas units.","Electric shock or fire from faulty wiring or overheating."]},"interfaces":{"applicability":"required","items":["IEC 60335-2-35, Household and similar electrical appliances, Particular requirements for instantaneous water heaters, International Electrotechnical Commission."]},"context":{"applicability":"required","items":["Instantaneous water heaters supply hot water on demand in homes, commercial premises and facilities with localized washing needs.","They may serve one outlet or several outlets, with suitability depending on available energy supply, incoming water temperature and simultaneous demand."]}},"sources":[{"title":"Wikidata item Q5953359: instantaneous water heater","url":"https://www.wikidata.org/wiki/Q5953359","note":"identity and sense of the item"},{"title":"Wikipedia: Tankless water heating","url":"https://en.wikipedia.org/wiki/Tankless_water_heating","note":"general description of the item"}],"openQuestions":["Which existing Vercy world model, if any, already owns this concept or its parent water-heater concept and should be linked instead of duplicated?","Where should the registry boundary fall for small-buffer tankless designs, heated taps and instantaneous domestic-water sections of combined boilers?","Which primary sources establish the applicable standards, issuing bodies and certification requirements for electric and fuel-fired variants in the intended jurisdictions?","What sourced capacity, activation-flow, pressure and dimension ranges are representative of point-of-use and whole-building variants under explicit rating conditions?","Which documented failure patterns and water-quality limits justify common diagnostic questions across variants, and which must remain manufacturer-specific?"],"resources":{"spec":"/models/things/publications/thing-q5953359/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q5953359/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T10:30:21Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:31+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}