Commercial Boilers, Heating & Hot Water
CHP Units
CHP units that run unmaintained lose efficiency long before failing outright, and by then, most of the potential energy savings are already gone. Because CHP ties electrical and heat output together, a single fault can affect both at once, unlike a standard boiler.
Robinsons Facilities Services coordinates CHP unit maintenance, repair, and installation for commercial buildings across Yorkshire and the Humber, working with specialist CHP engineers. We arrange the visit and manage the specialist from first call to sign-off.
Annual servicing typically from £600+VAT per unit, confirmed after we assess your engine size and running hours.
Get a quote for commercial CHP unit maintenance →
Prefer to speak to someone? Call us on 01423 226578 →
Combined heat and power (CHP) is a single gas engine that generates electricity and captures waste heat for heating and hot water at the same time. Well-maintained commercial CHP plant can reach total efficiencies of up to 80%, against around 50% for grid electricity and a separate boiler.
What is a CHP unit?
CHP units burn natural gas to drive an engine that generates electricity on site, and rather than letting the heat that process produces escape, a heat recovery system captures it for space heating, hot water, or process heat. It replaces buying electricity from the grid and running a separate boiler with one combined system.
Gas Safe registration and legal requirements
Most commercial CHP units run on natural gas, and any work on the gas side, from a routine check to a full engine overhaul, must be carried out by a Gas Safe registered engineer holding the right commercial qualification for CHP-scale plant. This is a legal requirement under the Gas Safety (Installation and Use) Regulations 1998, and it applies regardless of whether the unit is under a maintenance contract.
Routine CHP maintenance itself is not set out in law in the same way. It’s driven by manufacturer warranty terms and insurer requirements, plus the practical reality that an unmaintained gas engine loses efficiency and reliability quickly. Under the Health and Safety at Work etc. Act 1974, employers also have a general duty to keep work equipment, including on-site power generation, in a safe condition.
What a CHP maintenance visit includes
A typical CHP maintenance visit covers:
- Oil and filter changes, and spark plug replacement on gas engines that need them
- Engine health checks and fault diagnostics
- Cleaning the heat exchanger to keep heat recovery working efficiently
- Calibrating the controls that balance electricity and heat output
- Emissions testing to confirm the unit is running within its permitted limits
How often should a CHP unit be maintained?
Maintenance frequency depends on how hard the unit works. High-utilisation CHP plant, running most hours of the day, typically needs a maintenance visit every three months to stay within warranty terms and keep efficiency up. Lower-duty units, used only at peak times, can often run to a longer interval, closer to annual.
We assess your unit’s running hours and recommend a schedule that matches how it is actually used, rather than applying one interval to every site.
Why CHP maintenance matters
CHP earns its efficiency advantage by capturing heat a conventional generator would simply discard, but that advantage erodes quickly once a unit runs unmaintained. A neglected engine burns more fuel for the same output, the heat exchanger fouls and recovers less heat, and manufacturer warranties typically depend on proof of regular maintenance.
Pricing
CHP maintenance pricing varies more than most commercial services. Engine size and fuel type both affect the cost of a visit, and so does how many hours a year the unit runs.
A small single-unit installation and a larger multi-engine plant are different jobs, so we price CHP maintenance individually rather than publishing a flat rate.
Maintenance contracts: quoted individually
Annual servicing typically starts from £600+VAT per unit for a single, smaller installation, rising to £1,200 to £3,000+VAT a year for larger or multi-engine plant. Frequency, typically quarterly for high-utilisation plant or annually for lower-duty units, and the exact price are agreed after we assess your unit and its running hours.
This sits within a PPM and compliance contract, with maintenance for other building services combined where relevant.
Repairs and one-off works: quoted works
Faults and breakdowns, along with one-off jobs such as installation or a specific overhaul, are quoted through Quoted Works, with a fixed, itemised price confirmed before we start.
How we support you
We coordinate CHP unit maintenance, repair, and installation through a specialist CHP subcontractor network, covering the major commercial brands including ENER-G, EC Power, Yanmar, Capstone, 2G Energy, and Tedom. You get a single point of contact managing the visit, the paperwork, and the schedule, rather than dealing with the specialist directly.
Robinsons Facilities Services is Gas Safe registered and holds UKAS ISO 9001 certification. We manage CHP maintenance alongside the wider building services we look after for commercial clients across Yorkshire and the Humber.
Get a quote for commercial CHP unit maintenance →
Prefer to speak to someone? Call us on 01423 226578 →
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CHP Unit FAQs
As a guide, a single smaller unit typically costs from £600+VAT a year to service, while larger or multi-engine plant runs from £1,200 up to £3,000+VAT a year. What the engine runs on and how big it is both matter, and so does the number of hours it clocks up each year, so we confirm a fixed price once we’ve assessed your unit. Send us an enquiry or call us on 01423 226578 for a tailored quote.
CHP stands for combined heat and power, sometimes called cogeneration. Both terms describe the same thing: a system that produces electricity and useful heat from a single fuel source at the same time, on site, instead of two separate systems doing that job.
Usually every three months for a unit in near-continuous use, stretching toward annual for one that only runs occasionally. Running hours, not a blanket rule, set the right interval for a given site.
Not in the way people often assume. There is no law setting a fixed CHP maintenance interval. The legal part sits elsewhere: under the Gas Safety (Installation and Use) Regulations 1998, only a Gas Safe registered engineer with the right commercial qualification can touch the gas side of the unit. Beyond that, the schedule itself comes down to your equipment warranty, your insurer’s expectations, and keeping a costly asset performing as it should.
A typical visit covers an engine health and fault check, oil, filter, and spark plug replacement where fitted, a clean of the heat exchanger, calibration of the controls, and an emissions check to confirm the unit stays within its permitted limits.
Falling electrical or heat output, unusual noise or vibration from the engine, more frequent fault trips, higher fuel use for the same output, and visible leaks or unusual smells are all worth investigating. A unit that keeps tripping out or underperforming is often cheaper to repair early than to run until it fails outright.
We coordinate maintenance and repair for the major commercial CHP brands, including ENER-G, EC Power, Yanmar, Capstone, 2G Energy, and Tedom. If your unit is a different make, get in touch and we will confirm coverage.
Both. New CHP installations and larger replacement projects are handled through Quoted Works, with a fixed, itemised price agreed before any work begins, alongside our ongoing maintenance and repair service for units already on site.
Efficiency is usually the first thing to slip, and it can happen before there’s any obvious fault to point to. Left longer, wear on the engine accelerates and breakdowns become more frequent. Gaps in the maintenance record can also leave a warranty claim unsupported, and because electricity and heat come from the same engine, a problem rarely stays contained to just one side of the output.
Well-maintained commercial CHP plant typically reaches total efficiencies of up to 80%, against roughly 50% for buying grid electricity and heating separately with an on-site boiler. The gap comes from capturing the heat that conventional power generation simply discards.
Last updated: 15/09/2026
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