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James visits, gives a straight answer on suitability and a fixed estimate on the spot.
How to choose a heat pump installer comes down to two tests before anything else: the company should measure your house room by room before it names a size, and the person who designs the system should still be the one you speak to once it is running. Both tests matter most in an oil-heated house, where the new system replaces the only heat source and a size picked from a guess shows up in the first cold week. This guide sets out nine checks you can run on any of the heat pump installers in Devon who come to quote.
Key Takeaways
- Pick the installer who measures every room before naming a size, and whose designer stays your contact after commissioning.
- The grant is £7,500, or £9,000 for off-gas-grid homes on oil or LPG until 31 March 2027, and only an MCS certified installer can claim it for you.
- A quote without a radiator schedule, a cylinder size and a design flow temperature leaves the parts that decide comfort until after you sign.
- Many oil-heated East Devon homes we survey come out at 4 to 10 kW, so a much bigger figure for an ordinary three-bedroom house deserves a question.
- A stone or cob house turned down by one installer still deserves a measured survey, and a valid EPC is no longer needed to apply for the grant.
- Three quotes built on room-by-room surveys give you a fair comparison, so ask about the survey at every visit.
James Stalker runs Eco Pro Renewables from Exmouth and also works as a freelance NAPIT MCS assessor, so part of his week goes on inspecting heat pump installations other companies have fitted. Several of the checks below, the survey, the sizing and the flow temperature, sit inside the MCS standard he assesses those jobs against. The rest concern the company behind the quote, from the guarantee terms to the person you ring in January when a radiator runs cool.
Check 1: An MCS Certified Heat Pump Installer, and What It Means for Your Grant
An MCS certified installer is a company that a certification body, NAPIT for example, has assessed against the Microgeneration Certification Scheme standards for heat pump design and installation, and it has to keep meeting them to stay listed. The certificate matters to you because the Boiler Upgrade Scheme pays out only on MCS certified installations.
An MCS certified installer
- The grant £7,500, or £9,000 for off-gas-grid homes on oil or LPG until 31 March 2027
- How it reaches you The installer applies, and the grant comes off your invoice upfront
- Consumer code Certification requires membership of RECC or HIES. We are RECC members
A company has to hold certification the whole way through.
You never pay the grant yourself and wait for it to come back.
Installation carries 0% VAT until 31 March 2027 whichever certified company does the work, and the rules for this area are set out on our page about the Boiler Upgrade Scheme grant in Devon.
The certificate belongs to the company as a whole. It tells you the business passed an assessment, and the other eight checks tell you about the job it would do on your house.
Check 2: A Room-by-Room Heat Loss Survey Before Any Size Is Named
The MCS heat pump design standard, MIS 3005-D, requires the installer to select the heat pump from a room-by-room heat load calculation to BS EN 12831-1:2017. A figure that arrives after a phone call, from the floor area or from the old boiler’s rating has skipped that step.
Where the kilowatt figure on a quote came from
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A phone call
Skips the calculation
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The floor area
Skips the calculation
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The old boiler’s rating
Skips the calculation
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Every room measured: walls, windows and floors
What MIS 3005-D requires
Illustration: two Devon houses and the same guess.
We work in two stages. James visits for free, looks over the property, tells you if a heat pump suits it and leaves an estimate on the spot. The heat loss survey comes next and measures every room, wall construction, window and floor. It costs £250 plus VAT, waived in full if you go ahead with the installation.
At any first visit, ask who carries out the calculation and if you will get a copy with the room figures on it.
Check 3: Heat Pump Installation Red Flags Start With the Size
An oversized heat pump reaches temperature fast, switches off, cools and starts again, a pattern engineers call short cycling. Frequent cycling wears the compressor and pushes running costs up. An undersized unit does the opposite damage and leaves the back bedroom short in the coldest week of the year.
One cold day, as the compressor sees it
Illustration: how each unit runs, drawn without a scale.
Each shortcut in a survey pushes the size one way. Guess the draughts high, lean on an EPC in place of measurements or add a margin to be safe, and the kilowatt figure climbs, with a bigger price attached to the bigger unit. Many of the oil-heated East Devon homes we survey come out between 4 and 10 kW, so a quote well above that for an ordinary three-bedroom house deserves a question.
Check 4: A Quote That Covers the Radiators, the Cylinder and the Flow Temperature
A heat pump sends cooler water round the radiators than an oil boiler does. We design to a flow temperature of 45 to 50°C, and at that temperature some existing radiators give out less heat than their room loses on a cold night. The survey shows which ones, and often a few rooms need a larger radiator while the rest stay on the wall.
Hot water is the other half of the design. A heat pump needs a cylinder built for it, with a large coil and heavy insulation, sized to the household, and an old copper cylinder from the oil system will not do the job.
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Outdoor unit
Priced
- Radiator schedule To be confirmed
- Cylinder To be confirmed
- Design flow temperature To be confirmed
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Outdoor unit
Priced
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Radiator schedule
Room by room, in writing
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Cylinder
Built for a heat pump, sized to the household
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Design flow temperature
Stated on the quote
Illustration: two quotes for the same house.
Ask every installer for the radiator schedule, the cylinder and the design flow temperature in writing, with the price.
Check 5: How the Installer Treats an Older Devon Home
East Devon’s housing runs from 1960s bungalows to cob farmhouses and stone cottages whose solid walls have no cavity to fill. Some installers turn these houses away because they do not fit a standard package or a standard survey sheet. A “can’t be done” from one company reflects that company’s method, and the house itself may never have been measured.
Three walls, three different calculations
Illustration. The calculation uses the wall that is really there, never a default.
Solid stone and cob lose heat on their own terms, unlike cavity brick, which is why the measured heat loss leads the design. Our guide to heat pumps in old houses covers the building side in more detail.
Paperwork used to stop some of these homes as well. Since April 2026 a valid EPC is no longer required to apply for the Boiler Upgrade Scheme, and other evidence is accepted, so a cob cottage without a recent certificate can still go forward.
Check 6: An Independent Heat Pump Installer Chooses the Unit to Suit the House
Illustration: four air-to-water heat pumps of different sizes and builds beside a hot water cylinder.
Some heat pump installation companies fit one or two makes, often their own unit or a single manufacturer’s range. An independent heat pump installer can start from the survey result and choose the unit, its output, the cylinder and the controls from there.
Where the survey sits in the order of choice
Stock and training stay simple for the installer, and the survey ends by matching your house to whatever they sell.
Each choice starts from the survey result, which matters most when a house falls between two sizes in one maker’s range.
We install Ideal often, and we are not tied to one manufacturer. James selects the heat pump and cylinder that suit each property, which matters most when a house falls between two sizes in one maker’s range or has a tight cylinder cupboard. Ask every installer which makes they fit, and what they would do if your heat loss landed between two of their sizes.
Check 7: A Local Heat Pump Installer Who Stays With the Job
Ask who you will deal with at each stage. At a large installer the survey, the design, the fitting and the aftercare can each sit with a different person, and a customer with a question can get passed between a sales adviser, a call centre and a scheduling department.
Who you deal with, stage by stage
Each stage can sit with a different person.
James, from the first visit to aftercare
If something needs attention two winters later, you ring James and speak to the person who designed your system.
Every air source heat pump installation we carry out runs on that model.
A search for a heat pump installer near me returns a map full of names, and distance alone tells you little. The useful test is whether the person who designed your system can get to your house when it matters. We cover around an hour from Exmouth, which takes in heat pump installation around Exeter and the oil-heated villages to the east of the city.
Check 8: Guarantees, and the Small Print Behind a Long One
A long headline guarantee looks simple on a quote. Some sit inside a paid plan with a monthly fee, and the cover ends if you stop paying. Over ten or more years that fee adds up to a real sum on top of the installation price, so multiply it out before you compare two quotes.
Read what a long guarantee pays if the whole unit has to be replaced late in its term, because some plans pay less as the unit ages.
Three questions for any guarantee
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What does it include?
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What does it cost per month to keep?
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What would a full replacement claim in the later years leave you paying?
- No monthly plan attached
- An IWA workmanship warranty with deposit insurance on every job
- The manufacturer warranty registered at commissioning, on whichever heat pump we install
- On an Ideal, that means seven years of Ideal parts and labour
Check 9: Aftercare, Servicing and Who Turns Up
A heat pump needs a service once a year, and the question to settle before you sign is who carries it out. At Eco Pro, James does the servicing himself, and we contact you when your annual service is due.
Carried out by James himself.
- A full system inspection
- Checks and testing
- Cleaning where needed
- A written report on any defects or recommended work
Repair costs depend on the job and the location, and James talks them through on your first call and fixes a competitive price upfront. We also service most major air-to-water brands, including systems we did not install; the details are on our heat pump servicing page.
From any installer, find out who services the system in year three, whether that person has seen your design, and how soon they reach a breakdown in February.
How to Choose a Heat Pump Installer From Three Quotes
Three quotes is a sensible number for a decision this size, as long as each one comes from a survey of your house. Heat pump installation companies range from one-person specialists to national operations with regional crews, and their quotes look different on paper for that reason.
Set every quote out on the same lines
- The heat loss figure
- The unit size chosen from it
- The design flow temperature
- Radiator changes, room by room
- The cylinder
- The controls
- The guarantee and its monthly cost
- Who commissions the system
- Who services it
The grant is the same through any MCS certified installer, so the gap between two quotes sits in the design and the service around it.
Questions to Ask a Heat Pump Installer, and How to Read Their Reviews
If you are still weighing how to choose a heat pump installer, these questions pull the nine checks into one conversation at the kitchen table.
Eight questions for every installer who quotes
- Are you MCS certified, and which consumer code do you belong to?
- Who carries out the heat loss survey, and will I get the room figures?
- What size have you chosen, and why that size?
- Which flow temperature is the design built on, and which radiators change?
- Which cylinder is included, and which makes of heat pump do you fit?
- Who is my contact from the survey through to aftercare?
- What does the guarantee cost per month, and what would it pay out in year nine?
- Who services the system, and how fast do you attend a breakdown?
Heat pump installer reviews tell you more once you read past the stars. A review written on commissioning day says little about the first winter, so give more weight to the ones that cover the months after the install.
Frequently Asked Questions
Ask whether they are MCS certified and in a consumer code, who does the room-by-room heat loss survey, what size they chose and why, which radiators and cylinder the quote includes, the design flow temperature, who your contact is through aftercare, and what the guarantee costs per month to keep.
Book my free home assessmentMCS certification means a certification body has assessed the company against the Microgeneration Certification Scheme standards for design and installation. The Boiler Upgrade Scheme only pays on MCS certified installations, so an uncertified installer cannot claim the £7,500, or £9,000 for off-gas-grid oil and LPG homes, on your behalf.
Book my free home assessmentThree is a sensible number, as long as each installer surveys your house room by room before quoting. Compare them on the same lines: heat loss figure, unit size, flow temperature, radiator changes, cylinder, guarantee terms and who services the system.
Book my free home assessmentA size quoted without a room-by-room survey, a quote with no radiator or cylinder details, pressure to sign on the day, a salesperson who never meets the engineer, and a long guarantee that only runs while you keep paying a monthly plan.
Book my free home assessmentIt depends on the house. A national company can suit a simple modern home where price decides. A local specialist suits older or harder properties, where one named person designs the system, commissions it and handles the aftercare.
Book my free home assessmentAn MCS certified installer applies for the grant for you, and the amount comes off your invoice upfront. That is £7,500, or £9,000 for off-gas-grid homes on oil or LPG until 31 March 2027, the same across England and Wales. We handle the application on every eligible installation we fit.
Book my free home assessmentHow to Choose a Heat Pump Installer: Put Us Through the Same Nine Checks
Every check above comes down to something you can hold in your hand: a certificate you can look up, room figures on paper, a unit size with its reasoning, guarantee terms with the monthly cost beside them, and a phone number for the person who designed the system. At the free home assessment James looks over your property, tells you if a heat pump suits it and leaves an estimate, and you are welcome to put that visit through all nine checks.
Book my free home assessmentPrefer to talk it through first? Ring 01395 202030. James answers, and he is the person who will price the job.
★★★★★
“James and the team provided a first rate end to end service, our old oil boiler failed on Good Friday and within 3/4 weeks we were up and running with a new energy efficient air source heating system.”
Richard Drake · Google review
