Maintenance & PPM: capacity, cost and efficiency

What HVAC maintenance and PPM are, and why they are different from install work

Every other system on this site is about putting plant in. This one is about keeping it running, efficient and legal for the fifteen or twenty years it is in service — and it is where most facilities managers’ real day-to-day pain lives. PPM stands for Planned Preventative Maintenance: a schedule of visits, typically quarterly or six-monthly, that services your HVAC plant before it fails rather than after. It is the opposite of the reactive model, where you wait for a chiller to trip or an AHU fan to seize and then pay premium rates for an emergency call-out and unplanned downtime.

The distinction matters because the economics are different from an install. A PPM contract is a recurring cost that buys down three separate risks at once: the risk of breakdowns (planned servicing catches drift before it becomes failure), the risk of efficiency loss (dirty coils, worn belts and drifting controls quietly push running cost up year on year), and the risk of non-compliance (statutory F-gas leak checks and records that the law requires and the Environment Agency enforces). For most commercial buildings the contract costs less than the breakdowns, efficiency losses and compliance exposure it prevents — which is why it is a numbers decision, not a discretionary extra.

What a PPM contract actually covers

A commercial PPM contract is scheduled against your specific plant, following recognised task schedules — the SFG20 standard maintained by BESA, which defines what maintenance tasks each type of equipment needs and how often. A full contract across a mixed building typically covers:

• VRF and air conditioning — filter cleaning, coil condition, controls and refrigerant checks across the VRF systems.
• Chillers — compressor and refrigerant checks, free-cooling and control verification, and the more frequent F-gas leak checks that large chillers require.
• AHUs and ventilation — fan and belt condition, filter changes, heat-recovery performance and TR19 ductwork hygiene across the air handling and ventilation plant.
• Heat pumps — refrigerant, controls and performance checks that protect the SCOP on electrified plant.
• Controls and BMS — trending and set-point verification so the plant keeps running as designed rather than drifting.

The point of a contract, rather than ad-hoc servicing, is that one provider holds the whole picture — the plant register, the F-gas records, the leak-check calendar and the warranty conditions — so nothing falls through the gap.

The compliance angle — the statutory duty most owners cannot self-manage

This is the heart of the maintenance page and the reason PPM is not optional for most buildings. If your HVAC plant contains F-gas refrigerant, leak checks are a legal duty, and the frequency is set by the charge measured in CO2-equivalent:

• 5 tonnes CO2e or more — at least annual leak checks.
• 50 tonnes or more — six-monthly.
• 500 tonnes or more — quarterly.

Automatic leak detection can reduce some frequencies. Most commercial VRF crosses the 5-tonne line, and large chillers routinely sit in the six-monthly or quarterly band. The work must be carried out by an F-Gas registered company — certified by REFCOM, the Quidos F-Gas Register or Bureau Veritas, renewed every three years — using certified engineers, and refrigerant records must be kept. The Environment Agency enforces the regime. You can read the F-gas company certification requirements on GOV.UK, and REFCOM’s own F-gas company registration guidance. This is the compliance most owners genuinely cannot self-manage, and it is exactly what a PPM contract absorbs: the leak-check calendar, the certified engineers and the records, all handled.

Beyond F-gas, a full PPM regime also carries the other statutory duties that live in the plant room: TR19 ductwork-hygiene cleaning for fire safety, ACOP L8 Legionella control on water-cooled and wet systems, and NICEIC electrical checks. Pulling these into one scheduled, documented regime is what turns a scattered compliance headache into a managed, auditable programme.

The efficiency and warranty case

Two things owners often overlook about maintenance. First, efficiency drifts without it. Dirty coils, blocked filters, worn belts and drifting control set-points quietly erode the performance you paid for at install — a VRF or chiller can lose a meaningful slice of its efficiency over a couple of neglected years, and you pay for that in every electricity bill. Planned servicing holds the performance year on year. Second, manufacturer warranties usually require documented PPM. Skip the scheduled maintenance and you can void the warranty on a six-figure asset, so that when a compressor fails out of warranty you carry the full cost. The maintenance contract protects the capital investment, not just the comfort.

Remote monitoring and BMS trending sharpen all of this. Many modern systems can be monitored remotely so that drift, faults and inefficiencies are flagged before they become breakdowns — a fault caught on a Tuesday trend is a service visit; the same fault ignored is a Friday-afternoon emergency call-out with the building too hot or too cold and tenants complaining.

What a good contract looks like — how to choose a provider

Not all PPM contracts are equal, and knowing what to ask for protects you from a schedule that looks cheap on paper but leaves gaps. A good contract starts with a proper asset register — every piece of plant surveyed, listed, and matched to its SFG20 task schedule and, crucially, its F-gas leak-check frequency, so the visits are keyed to what your plant actually needs rather than a generic annual call. It sets out response times for reactive call-outs alongside the planned visits (a critical data-suite cooling fault needs a different response commitment from a comfort niggle), and it makes clear what is included in the contract price and what is chargeable — parts, out-of-hours attendance, specialist cleans.

The provider must hold current F-Gas certification (REFCOM, Quidos or Bureau Veritas), because that is a legal precondition of the refrigerant work, and ideally works to BESA / SFG20 standards with documented records you can produce for an insurer, a landlord or the Environment Agency. The single most useful test of a contract is whether one provider is willing to hold the whole picture — the asset register, the compliance calendar, the records and the warranties — so that nothing falls between suppliers. Fragmenting the work across whoever is cheapest each time is precisely how leak-check dates get missed and warranties get voided.

Sizing and economics

PPM is priced against your actual installed plant and its F-gas leak-check frequency, not a flat rate. Indicative annual contract values run from around £1,500 for a small building with a single VRF system up to £40,000 or more for a large mixed estate with chillers, AHUs, ventilation and heat pumps on quarterly leak-check cycles. The comparison that matters is not the contract price in isolation but the whole cost of the alternative: reactive call-outs at premium rates, unplanned downtime, drifting efficiency and compliance exposure. Most buildings find the planned contract costs less than the reactive model it replaces. There are indicative ranges for every system type on our cost guide.

How maintenance protects the electrification ladder

Maintenance is the recurring-revenue hub that protects every other measure on this site. There is little point specifying efficient low-GWP VRF, a free-cooling chiller, heat-recovery ventilation or a well-modelled heat pump if the plant is then left to drift out of tune and out of compliance. PPM is what keeps the efficient, electrified building performing at the numbers it was designed to hit — protecting the SCOP on the heat pumps, the part-load efficiency on the chillers, and the EPC rating that underpins the building’s MEES lettability year after year. It is the discipline that makes the whole commercial HVAC strategy hold up over time.

Objections we hear, answered honestly

“We keep getting hit with reactive call-outs — is a contract actually worth it?” Almost always, and not just for fewer breakdowns. A PPM contract handles your statutory F-gas leak checks and records so you stay legal, catches faults early before they become emergency call-outs at premium rates, and holds your plant’s efficiency so running cost does not drift. Most buildings find the contract costs less than the reactive model it replaces. We price it against your actual plant.

“Our plant is fairly new — surely it does not need maintenance yet?” New plant is exactly what you want to protect. Manufacturer warranties commonly require documented PPM, so skipping it can void the cover on an expensive asset. And F-gas leak checks are a legal duty from day one, regardless of the plant’s age — the Environment Agency does not exempt new systems.

“Can we just do it ourselves or use whoever is cheapest each time?” You can service some things in-house, but the statutory F-gas work must be done by an F-Gas registered company with certified engineers and proper records — and fragmenting the work across different providers is how leak-check dates get missed and warranties get voided. A single contract holds the whole plant register, calendar and records in one place.

What actually happens on a maintenance visit

It helps to know what a planned visit involves, because the value of PPM is in the detail rather than a tick on a form. On a typical service the engineer works through the SFG20 task schedule for each item of plant: checking and cleaning filters and coils, inspecting fans, belts and bearings, verifying refrigerant pressures and checking for leaks, testing controls and safety devices, and confirming the plant is holding its design performance rather than drifting. On systems in F-gas scope, the statutory leak check is carried out and logged with the refrigerant records updated. Anything found — a worn belt, a control drifting off set-point, a filter close to blocked — is reported with a recommendation, so small faults are fixed before they become failures. The visit ends with documentation: a service record, the compliance log, and any remedial actions, all of which you can produce for an insurer, a landlord or the Environment Agency. That paper trail is as much the point as the spanner work, because it is what proves the plant is maintained, compliant and warranty-protected.

Frequently asked questions

What is a PPM contract and do I need one?

PPM stands for Planned Preventative Maintenance — scheduled visits (usually quarterly or six-monthly) that keep your HVAC plant efficient, compliant and running. It handles statutory F-gas leak checks and records, catches faults before they become reactive call-outs, and protects manufacturer warranties, which commonly require documented maintenance. For most commercial buildings the contract costs less than the breakdowns and compliance risk it prevents.

How often do I need F-gas leak checks?

By charge: at least annually at 5 tonnes CO2-equivalent, six-monthly at 50 tonnes, and quarterly at 500 tonnes, with automatic leak detection able to reduce some frequencies. Most commercial VRF crosses the 5-tonne line and large chillers sit higher. The checks must be done by an F-Gas registered company with records kept, and are normally handled inside the PPM contract.

Will maintenance really save me money?

Usually, in three ways: it holds plant efficiency so running cost does not drift up, it replaces premium-rate emergency call-outs with planned servicing, and it keeps you compliant and warranty-protected so you avoid large uninsured failures. The comparison is against the whole cost of the reactive alternative, not the contract price alone.

Does a maintenance contract cover ductwork and Legionella?

A full PPM regime pulls in TR19 ductwork-hygiene cleaning for fire safety and ACOP L8 Legionella control on water-cooled and wet systems, alongside the F-gas and electrical duties. Bringing these into one scheduled, documented programme is much of the point of a contract.

Do I lose my warranty without maintenance?

Often, yes. Many manufacturer warranties require documented planned maintenance as a condition, so skipping PPM can void the cover on a six-figure asset — leaving you to carry the full cost if a compressor or major component fails. The contract protects the capital, not just comfort.

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We provide commercial HVAC maintenance and PPM across the UK, including London, Manchester and Birmingham, across VRF, chillers, AHUs, ventilation and heat pumps. For a plant survey and a PPM proposal priced to your F-gas leak-check duties, request a quote, or read the most common commercial HVAC questions.