ACV by Gas Safe registered commercial engineers
We provide acv for businesses, landlords and facilities managers across London. Gas-fired water heaters supply hot water to restaurants, hotels, gyms, schools and offices. Storage heaters and continuous-flow units both need regular servicing to keep scale, combustion and flueing under control, and quick repairs when hot water stops.
ACV is part of our commercial water heaters work. Whether you manage one site or a portfolio, you get the same engineers, the same standards and clear paperwork after every visit.
Commercial gas work is different from domestic work. Loads are larger, pipework runs further and safety controls such as interlocks, valve proving and flame supervision are more complex. That is why we only send engineers who work on commercial installations every day and know the equipment found in London plant rooms and kitchens.
What's included
- HeatMaster servicing
- Prestige repairs
- Tank-in-tank inspection
- Fault diagnosis
Before arranging a visit for ACV
Describe the hot-water symptom precisely: no hot water, slow recovery, fluctuating outlet temperature, a leak or a burner lockout. The engineer also needs to know whether the system is storage, continuous-flow or a bank of units and how many outlets it serves at peak demand. A photo of the heater data plate and any controller display helps identify the right documentation. If hot water serves food preparation, care or hygiene facilities, explain the operational impact when booking.
When you contact us about ACV, describe what has changed since the equipment last worked normally. Include the make and model if you can read them safely, the number of affected appliances and any previous repair or inspection findings. Do not remove covers or attempt a reset repeatedly to collect this information. These details help define the visit, but they do not replace an on-site assessment by an appropriately qualified engineer.
What each part of the work involves
The scope below follows the work listed for ACV. Not every installation needs the same action: the engineer will confirm what applies to your site before work starts and explain any additional work that a test or inspection identifies.
HeatMaster servicing
For ACV, this starts with confirming the equipment and the boundary of the work at the premises. The step listed as “HeatMaster servicing” is not a box to tick from a description alone: the engineer needs access to the actual installation and its operating information. The result informs the next part of the visit, “Prestige repairs”; if the first check reveals a defect, the sequence may need to change for safety. For Commercial Water Heaters, the correct test method and acceptance criteria depend on the appliance or installation, not on a generic checklist. Ask which readings or observations support the conclusion, what they mean for safe use now, and what remains to be done before the next planned visit.
Prestige repairs
At this stage of ACV, the step “Prestige repairs” must be assessed against the equipment that is actually fitted. The engineer checks whether earlier alterations, site conditions or manufacturer instructions change the proposed approach. The result informs the next part of the visit, “Tank-in-tank inspection”; if the first check reveals a defect, the sequence may need to change for safety. For Commercial Water Heaters, the correct test method and acceptance criteria depend on the appliance or installation, not on a generic checklist. Ask which readings or observations support the conclusion, what they mean for safe use now, and what remains to be done before the next planned visit.
Tank-in-tank inspection
The practical work includes the step “Tank-in-tank inspection”. It should be coordinated with the person responsible for the site, particularly if an appliance or supply must be isolated while the work is in progress. The result informs the next part of the visit, “Fault diagnosis”; if the first check reveals a defect, the sequence may need to change for safety. For Commercial Water Heaters, the correct test method and acceptance criteria depend on the appliance or installation, not on a generic checklist. Ask which readings or observations support the conclusion, what they mean for safe use now, and what remains to be done before the next planned visit.
Fault diagnosis
Before the ACV visit is closed, the step “Fault diagnosis” needs a clear recorded outcome. The engineer should explain any limitation or further action instead of leaving an unexplained result on a form. The final record should distinguish completed tests from recommendations, and identify anything that has deliberately been left out of service. For Commercial Water Heaters, the correct test method and acceptance criteria depend on the appliance or installation, not on a generic checklist. Ask which readings or observations support the conclusion, what they mean for safe use now, and what remains to be done before the next planned visit.
Choosing the right next step
A hot-water failure may originate in the burner, gas supply, controls, heat exchanger, scale build-up or downstream distribution. On storage systems, tank condition and any sacrificial anode matter; on continuous-flow installations, filters and flow demand can be critical. A replacement should be sized for simultaneous demand and recovery, not simply matched to the physical size of the existing unit. Unvented components and temperature controls require the appropriate competence and must not be bypassed to restore supply.
A quotation or visit description should tell you whether the aim is to diagnose, make safe, repair, install, inspect or commission. Those are different outcomes. For ACV, ask whether an interruption to the gas supply is expected, whether other trades or the site manager must attend, and which checks are needed before equipment can be put back into use. If a fault persists after an earlier repair, share the earlier findings so the engineer can investigate the whole sequence rather than repeating the same intervention.
How the job runs
- Call or book online. Tell us the site, the equipment and the problem. We confirm an arrival window, usually the same or next day.
- Survey and safety check. The engineer checks the installation, confirms the scope and explains anything unsafe before starting.
- The work. HeatMaster servicing, then the remaining tasks above, carried out with minimal disruption to your staff and customers.
- Testing and paperwork. Everything is tested before we leave and you receive a written record you can hand to your insurer or landlord.
Standards we work to
Commercial water heaters are installed and serviced to BS 6644 or BS 5546 as applicable, with unvented safety devices checked to G3 Building Regulations and legionella temperatures maintained to HSG274. Every engineer carries a Gas Safe ID card showing their non-domestic categories, and calibrated test equipment is used on every job.
Records and handover for ACV
The visit record should identify the heater, checks performed, combustion results where applicable, safety device findings and any limits on use. Keep water-side maintenance and gas-side service records together, as scale and temperature problems can present like burner faults. If the unit is one of several feeding a shared system, confirm which heaters were returned to service and whether peak demand remains covered. An inspection does not replace your site's water hygiene management arrangements.
Keep the visit report with any earlier certificates, drawings and manufacturer instructions for the same equipment. If the engineer recommends follow-up work, record who will arrange it and whether the affected item may be operated meanwhile. This is particularly important where a site changes shifts or where the person booking the visit is not the person operating the equipment. Ask for clarification before the engineer leaves if the outcome or next step is unclear.
Who we work for
Our acv customers include restaurants, hotels, gyms, schools, hospitals, care homes and office washrooms. We regularly work out of hours and at weekends so kitchens can keep trading and buildings stay open. Managing agents and FM companies can set up an account for multiple sites with consolidated records.
Why choose us for acv
- Commercial-only Gas Safe registered engineers
- Same-day response available across London
- Written reports and certificates for every visit
- Fixed quotes for planned work, no hidden extras
- Out-of-hours and weekend appointments
Planning, access and cost
Most acv jobs can be planned around your opening hours. Tell us about access arrangements, permits, parking and any restricted areas when you book, and send photos of data plates or fault codes if you have them, so the engineer arrives with the right parts. For planned work we confirm a fixed price in writing before we start. For reactive call-outs the first hour covers attendance and diagnosis, and we will not carry out further chargeable work without your approval.
Staying safe between visits
If you smell gas, turn off the supply at the emergency control valve, open doors and windows, avoid operating electrical switches and call the National Gas Emergency Service on 0800 111 999 before calling us. Keep plant rooms clear of storage, keep ventilation grilles unobstructed and log any lockouts or unusual noises. Good records help our engineers find faults faster and keep your certificates straightforward to renew.
Areas covered
We provide acv throughout Greater London, including City of London, Westminster, Camden, Islington, Hackney, Tower Hamlets, Southwark, Lambeth, Kensington & Chelsea, Hammersmith & Fulham, Wandsworth, Greenwich, Lewisham, Newham, Croydon, Bromley, Barnet, Brent, Ealing, Hounslow, Hillingdon, Harrow, Enfield, Haringey and every other London borough.