--- title: "BMS Call Out London: 24/7 Emergency Response | BIAV Controls" description: "24/7 BMS emergency call-out across London. Phones answered every day, 2-hour on-site SLA for contract clients, 24-hour response for reactive call-outs. 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There are no 'from' prices; every site is different." } }, { "@type": "Question", "name": "Can you help if you didn't install the system?", "acceptedAnswer": { "@type": "Answer", "text": "Yes, most of our call-out book is on third-party installs, across every open protocol and major manufacturer." } }, { "@type": "Question", "name": "Do you attend healthcare / NHS sites out-of-hours?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. Hospital plantroom call-outs, including 3am attendances, are a regular part of our work under formal NHS contract SLAs." } }, { "@type": "Question", "name": "Will you leave the system in override?", "acceptedAnswer": { "@type": "Answer", "text": "No. Every call-out closes with the sequence restored, overrides cleared and a written report, including root cause and any follow-up recommendation." } }, { "@type": "Question", "name": "Can you fix it remotely?", "acceptedAnswer": { "@type": "Answer", "text": "Often yes. If remote access exists we log in immediately and resolve where we can; many faults never need an engineer to leave the depot." } }, { "@type": "Question", "name": "Do you provide a call-out report?", "acceptedAnswer": { "@type": "Answer", "text": "Every attendance closes with a written report: what was found, what was changed, root cause and any follow-up recommendations." } } ] } ] --- 52 Selah Drive, Swanley, BR8 7WD 24/7 phones answered · 2hr SLA response [accounts@biav-controls.co.uk](mailto:accounts@biav-controls.co.uk)[](https://www.instagram.com/biav_controls)[](https://www.linkedin.com/in/bradley-thomas-62a0901b6/) [![BIAV Controls](/__l5e/assets-v1/aa32365b-edd5-4700-8950-51fcbb3a024c/biav-logo.webp)](/) Services Service Areas [About](/about) Our Work [Contact](/contact) [07782 247022](tel:+447782247022)[Request a Quote](/contact) ![Trend IQView4 HMI showing an active AHU Common Fault alarm attended on a BMS call-out](/__l5e/assets-v1/52077a86-d494-4089-a291-676bc7275e13/Another_call_out_for_a_alarm_on_AHU_system.jpeg) BMS Call Out · London & the South East # 24/7 BMS call-out across London, phones answered, engineers on-site, not a shared voicemail. Contract clients see a controls engineer on-site within two hours, including 3am NHS call-outs. Reactive call-outs answered day-of and responded to within 24 hours. [Request a Quote](/contact) [Call 07782 247022](tel:+447782247022) 13+ years hands-on BMS experience 2-hour on-site SLA for contract clients 1-year workmanship warranty 1. [Home ](/) 2. [Services](/services) 3. BMS Call Out 13+ Years hands-on BMS experience 2 hr On-site SLA for contract clients 24/7 Phones answered, every day £20M Public liability insurance BS EN 61439 Panel build standard Service overview ## BMS Call Out, explainedwithout the marketing gloss. What it is A BMS call-out is an urgent visit to diagnose and rectify a fault on the Building Management System or the plant it controls: no-heat, no-cooling, comms failure, supervisor crash, alarm storm, network dropout or safety interlock trip. Who it's for Facilities managers, duty engineers, hospital estates teams, landlords and M&E contractors who need a specialist controls engineer on-site now, not a returned-call ticket in a queue. When you need it As soon as the BMS or the plant it controls stops behaving. Common triggers: overnight plant lockouts, comms loss to controllers, boiler or chiller sequence failure, tenant complaints about temperature, alarm storms in the small hours, or a supervisor front-end going offline. Why professional matters A generic maintenance contractor can attend the plant. Only a controls engineer can read the graphics, interrogate the logic, isolate whether the fault is mechanical or controls, and restore the sequence without leaving the site in override. The cost of ignoring it ## What happens whenthis gets left alone. The wrong call-out response turns a two-hour fix into a two-week problem. Risks & cost escalation - Manual overrides left in place after a rushed fix drain energy for months before anyone notices. - Undiagnosed comms faults quietly disable safety interlocks and alarms; the building looks fine on the graphic while the plant runs blind. - A supervisor left down means every alarm, trend and history stops recording: evidence for later audits is gone. - Repeated call-outs to the same fault, none of them root-caused, are a warning sign the BMS is quietly failing. - In a hospital or data-centre setting, delayed response is not an inconvenience: it's a clinical, tenant or SLA event. Common mistakes we see - × Calling the M&E contractor first when the fault is on the controls side; the call gets escalated a day later. - × Accepting 'we've got it running, we'll come back': a fix without root-cause is a fix that returns. - × No written record of the call-out: no report means no learning and no evidence. - × Assuming out-of-hours means a voicemail. It shouldn't. Our process ## How we deliverbms call out. 1. Step 01 Live phone triage Phones are answered 24/7 by an engineer who can read the site, not a call handler. We take the fault details, site access, and any on-site contact. 2. Step 02 Remote interrogation Where remote access exists we log in immediately; often we can diagnose and clear the fault before anyone is dispatched. 3. Step 03 Response dispatch Contract clients: on-site within the SLA, typically 2 hours, including out-of-hours. Reactive non-contract call-outs: response within 24 hours. 4. Step 04 Diagnose & rectify Fault isolated to controls, network, mechanical or electrical. Rectified where we can; escalated to the correct trade where required, with clear evidence, not guesswork. 5. Step 05 Restore & document Sequence restored, overrides cleared, alarms acknowledged, back-up taken. Written call-out report issued with root cause and follow-up recommendations. 6. Step 06 Post-incident review For contract clients, recurring or high-impact call-outs trigger a post-incident review, so the same fault doesn't reappear next month. Outcomes you can measure ## What the right bms call outactually gives you. Human phone response 24/7 phones answered by an engineer, every day of the year. 2-hour SLA available Contract clients, including NHS estates, see an engineer on-site within two hours, out-of-hours included. Remote-first triage Faults resolved remotely wherever possible, often before anyone leaves the depot. Root-cause fixes Every call-out closes with a documented root cause, not a temporary override. Written call-out reports You get a written record for every attendance: evidence for insurance, landlord and regulatory audits. One point of contact The engineer on the phone is a controls engineer who can attend, not a triage layer between you and the fix. Scope & specifics ## Detail thatbuyers ask about. Call-outs vary in urgency, complexity and blame allocation. Common categories we attend: Materials, methods & standards All call-out work is performed by controls engineers. Any electrical intervention is carried out by partner electricians (NICEIC/NAPIT/ECA/ECS/CSCS). Panels remain compliant with BS EN 61439: no bodges, no untested tweaks. £20M public liability, £10M employers' liability, £10M professional indemnity. Residential vs commercial Commercial and healthcare call-outs are typically triggered by BMS alarms and formal SLAs. Residential and mixed-use call-outs are often triggered by resident/tenant comfort complaints; the diagnostic approach is the same but the communication path differs. Plant lockout & no-heat / no-cool Boiler, chiller, AHU or FCU lockouts investigated at controls level before the mechanical trade is called, often a sensor, actuator or interlock fault. Supervisor / front-end failure Niagara AX / N4, EC-Net, or generic supervisor down: restored from off-site back-up where we hold one, or rebuilt/patched on-site. Comms & network faults Loss of BACnet/IP, MS/TP, Modbus RTU/TCP, KNX, LON or M-Bus segments: token-passing, bias, terminators, cable damage and gateway failures all investigated. Alarm storms & spurious alarms Root-cause investigation of alarm floods, usually a single failed device or a bad threshold cascading through the schema. Post-fit-out defects Snagging call-outs on newly commissioned systems; we attend both projects we installed and third-party installs. Healthcare & critical-care call-outs Attendance to NHS and private-healthcare estates under strict SLAs, including out-of-hours theatre, ward and pharmacy plantrooms. Related services [BMS Maintenance](/services/bms-maintenance) [BMS Service](/services/bms-service) [BMS Software & Graphics](/services/bms-software-graphics) Recent work ## BMS Call Outon real sites. ![Trend IQView4 HMI showing an active AHU Common Fault alarm attended on a BMS call-out](/__l5e/assets-v1/52077a86-d494-4089-a291-676bc7275e13/Another_call_out_for_a_alarm_on_AHU_system.jpeg)![Trend IQ3xcite BMS controller with expansion modules inspected during an AHU alarm call-out](/__l5e/assets-v1/dffaeeb2-7c6b-4833-b9f4-ccd14b8d024e/Another_call_out_for_a_alarm_on_AHU_system2.jpeg)![BMS control panel with MCB protection and terminal blocks investigated on an AHU alarm call-out](/__l5e/assets-v1/c910a90b-4231-41d6-8979-3b3d15614f0c/Another_call_out_for_a_alarm_on_AHU_system3.jpeg)![Megaflo cylinder and heating plant in a high-end London residential property attended on a BMS call-out](/__l5e/assets-v1/58121e22-c2a7-44bb-9d52-1e4c03c30803/Call_out_on_a_high_end_residential_property.jpeg)![Modern BMS panel with Distech controllers and Kamstrup metering attended on a call-out](/__l5e/assets-v1/9fd4d046-e6ce-434c-88a5-e11076ae26b5/This_was_a_call-out.jpeg)![BIAV Controls engineer diagnosing a tenant-floor FCU fault via the BMS graphics on a weekend call-out](/__l5e/assets-v1/8bedc425-9208-42a6-b78f-19fd64942dd9/Weekend_works_for_a_urgent_call_out_on_a_tentant_floor_for_a_break_down_on_the_FCU_system_2.jpeg) Coverage ### Delivered across London & the South East Based in Swanley on the London/Kent border. Engineers cover the City, the South East London boroughs, north-west Kent and beyond. [Swanley ](/service-areas/swanley)[Dartford ](/service-areas/dartford)[Sevenoaks ](/service-areas/sevenoaks)[Orpington ](/service-areas/orpington)[Sidcup ](/service-areas/sidcup)[Bexley ](/service-areas/bexley)[Bromley ](/service-areas/bromley)[Greenwich ](/service-areas/greenwich)[Croydon ](/service-areas/croydon)[Gravesend ](/service-areas/gravesend)[South East London ](/service-areas/south-east-london)[City of London ](/service-areas/city-of-london)[Canary Wharf ](/service-areas/canary-wharf) FAQs ## BMS Call Outquestions, answered. Anything not covered here? Call us on [07782 247022](tel:+447782247022). Pricing BMS work is bespoke and project-based; pricing is **quote on application**, issued in writing after a site or specification review. ### Are your phones really answered at 3am? + Yes, 24/7, 365. Phones are answered by an engineer, not an out-of-hours call-handling service. ### How fast will you be on-site? + Contract clients: per SLA, typically 2 hours, including out-of-hours. Reactive non-contract call-outs: response within 24 hours. ### How much does a call-out cost? + Call-outs are priced against the SLA in your contract; reactive call-outs are quoted on application before we attend. There are no 'from' prices; every site is different. ### Can you help if you didn't install the system? + Yes, most of our call-out book is on third-party installs, across every open protocol and major manufacturer. ### Do you attend healthcare / NHS sites out-of-hours? + Yes. Hospital plantroom call-outs, including 3am attendances, are a regular part of our work under formal NHS contract SLAs. ### Will you leave the system in override? + No. Every call-out closes with the sequence restored, overrides cleared and a written report, including root cause and any follow-up recommendation. ### Can you fix it remotely? + Often yes. If remote access exists we log in immediately and resolve where we can; many faults never need an engineer to leave the depot. ### Do you provide a call-out report? + Every attendance closes with a written report: what was found, what was changed, root cause and any follow-up recommendations. Request a quote ## Send us the spec.We'll come back with a fixed scope. Every bms call out enquiry is scoped and quoted in writing: no 'from' prices, no hidden variations, no proprietary lock-in. Response within one working day, sooner for anything urgent. [Call 07782 247022](tel:+447782247022)[Full contact details](/contact) 24/7 phones answered £20M PL / £10M PI cover 1-year workmanship warranty BMS Call Out enquiry Tell us about the site. ![BIAV Controls](/__l5e/assets-v1/aa32365b-edd5-4700-8950-51fcbb3a024c/biav-logo.webp) Family-run BMS specialist delivering smart, energy-efficient solutions to support net zero buildings across London and the South East. Bespoke design, BS EN 61439 panels, open-protocol systems. [07782 247022 ](tel:+447782247022)[accounts@biav-controls.co.uk](mailto:accounts@biav-controls.co.uk) 52 Selah Drive Swanley, Sevenoaks BR8 7WD [](https://www.instagram.com/biav_controls)[](https://www.linkedin.com/in/bradley-thomas-62a0901b6/) Services - [BMS Service](/services/bms-service) - [BMS Installation](/services/bms-installation) - [BMS Call Out](/services/bms-call-out) - [BMS Pre-Design](/services/bms-pre-design) - [BMS Projects](/services/bms-projects) - [BMS Panel Manufacturing](/services/bms-panel-manufacturing) - [BMS Software & Graphics](/services/bms-software-graphics) - [BMS Electrical Installation](/services/bms-electrical-installation) - [BMS Maintenance](/services/bms-maintenance) - [BMS Energy Optimisation](/services/bms-energy-optimisation) Service Areas - [Swanley](/service-areas/swanley) - [Dartford](/service-areas/dartford) - [Sevenoaks](/service-areas/sevenoaks) - [Orpington](/service-areas/orpington) - [Sidcup](/service-areas/sidcup) - [Bexley](/service-areas/bexley) - [Bromley](/service-areas/bromley) - [Greenwich](/service-areas/greenwich) - [Croydon](/service-areas/croydon) - [Gravesend](/service-areas/gravesend) - [South East London](/service-areas/south-east-london) - [City of London](/service-areas/city-of-london) - [Canary Wharf](/service-areas/canary-wharf) Company - [About](/about) - [Our Work](/our-work) - [Case Studies](/case-studies) - [FAQs](/faq) - [Contact](/contact) - [Leave a review](https://search.google.com/local/writereview?placeid=ChIJDUK3gbWt2EcRTEnbDZS2st8) Hours: 24/7 Company No. 16344714 © 2026 BIAV Controls Limited. 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