Home / Cost guides / What a boxed-in boiler quote should separate
What a boxed-in boiler quote should separate
A boxed-in boiler price is a joiner's cupboard plus whatever a Gas Safe engineer needs to see ventilation, the flue and the condensate pipe. Compare cupboard quotes, and keep Gas Safe access as its own line.
Last reviewed:Two trades, two pieces of paper
People box a boiler in because the case sits in a kitchen and they want a door in front of it. The timber, the hinges and the paint are joinery. The appliance behind the door is a gas appliance if it burns gas. Those are different responsibilities, and a single "box it in" price often hides the join. Ask for the cupboard as one quote and for a Gas Safe visit as another, even if one firm offers both. You should be able to see which line pays for wood and which line pays for someone who is allowed to work on the appliance.
| Line | Which person should write it |
|---|---|
| Cupboard size, door swing and material | Joiner |
| Whether the case, the air path and the flue remain visible with the door open | Ask the Gas Safe engineer before the box is built [S1] |
| Condensate pipe: size, support and termination left as they are, or moved | Engineer, if anything moves [S1] |
| Manufacturer's instructions in the house, yes or no | You, so the visit is not visual-only by default [S1] |
| Making good the tiles and the worktop | Joiner |
| A new boiler, if the visit turns into a replacement | A different job. Do not fold it into the cupboard |
| VAT on each quote | Included or not. Registration when taxable turnover for the last 12 months goes over £90,000 [S4] |
What the inspection sheet is willing to list
The Gas Safe consumer inspection factsheet (February 2026, version 6) is about how inspectors visit, not a carpentry manual [S1]. For a gas-fed boiler, and only where access allows, it includes ventilation, the chimney or flue, and where the pressure relief terminates [S1]. It includes the condensate discharge pipe: size, how it is supported, and where it ends [S1]. Pressure-relief termination is the relief route. It is not a gauge number. Ask the engineer for the gauge figure in the manufacturer's instructions, and do not guess one.
If the instructions are missing, the sheet says the inspector may be limited to looking and may not run operational checks [S1]. Find the booklet before you ask for a cupboard. If you cannot find it, say so. The sheet also says an inspector will not go onto a roof, into a loft that lacks suitable access, or after concealed pipework where access would damage the property or be an unacceptable risk [S1]. Use that list as the standard of "we could not check it". Then ask, in writing, whether the cupboard you want would put the case or the pipe into that kind of limit. The answer belongs to the engineer, not to a mood board.
Gas Safe Register. QuoteZila is not affiliated with this organisation.
If the appliance worries you, stop the joinery
On the HSE domestic gas FAQ, it is illegal to use a gas appliance you suspect is unsafe [S2]. Turn it off and do not touch it until a Gas Safe registered engineer has checked it [S2]. That is HSE's instruction for an unsafe appliance. It is not an invitation to open the case, drain anything, or alter a filling loop.
Anyone you employ to work on the appliance must be on the register and competent for that work [S2]. The card shows the competencies [S2]. You can check the register online or call 0800 408 5500 [S2]. HSE strongly advises an annual service of appliances, flues and pipework by a registered engineer [S2]. A cupboard project is a sensible moment to book that service first, and to ask the engineer to say whether the box can be built afterwards.
A new or replacement boiler is a different example of work. Do not fold a replacement into the cupboard price. If the engineer says the appliance should be replaced, get a separate quote and ask them about building regulations for that replacement. Do not let the joiner start a box around a boiler that is about to leave.
How to compare the paperwork
Citizens Advice wants written quotes, a fixed price rather than a rough guess, and ideally three traders [S3]. For this job, "three" may mean three joiners, while the gas question is one registered engineer you have checked yourself. Do not average them into one number. Be wary of a cupboard price far below the others if it never mentions the flue or the air path [S3]. The paper should show a fixed total, a breakdown, how long it stays open, and whether VAT is included [S3].
Some firms charge to come and measure a kitchen. Ask first. Deposits: avoid one where you can. If you cannot, do not agree to more than 25%, get a receipt, and ask about protection if the firm stops [S3]. Ask to see insurance for the joiner that lasts until the door is hung, and do the Gas Safe check on anyone who will touch the appliance [S2] [S3].
The door, the tiles and the day after
A cupboard fails in ordinary use when the door will not open far enough for a person to stand at the case, or when it swings into a dishwasher that is already there. Ask the joiner to write the swing on a sketch of the kitchen, including the handle and the worktop it must clear. Tiles that have to be cut around a new frame are making good. If they are missing from the quote, the wall will still be unfinished when the door is hung.
Ask what happens to the existing shelf, the washing tablets and the boiler instructions that currently live in that corner. A box that leaves no shelf for the instructions fights the factsheet's request to have those instructions ready [S1]. You can keep them in a drawer nearby. Say where, so the next visit is not a search.
If the kitchen is being replaced in the same month, keep the boiler box out of the kitchen fitter's lump sum until the engineer has answered. A fitter who panels over the case as part of a run of units has still created the access question. The units can be priced. The gas question stays on its own page of the quote.
Kitchens in Cheshire
QuoteZila is new, starting in Cheshire with Crewe, Nantwich and Sandbach. Anyone in the UK can still post a job or register a business [QZ5]. Photograph the boiler from the doorway, say whether the instructions are in a drawer, and say you want the joiner and the engineer as separate lines. How many people reply depends on who has joined [QZ5].
Honest status: QuoteZila is new. We're starting in Cheshire, beginning with Crewe, Nantwich and Sandbach, and growing area by area. Anyone in the UK can still post a job or register a business. How fast you get quotes depends on how many local businesses have joined near you. Businesses can register and receive jobs straight away. We don't check insurance, qualifications or registrations, so please check these yourself before you hire.
Up to five matched local businesses can send quotes [QZ2]. QuoteZila is free for customers and local businesses [QZ1].
Posting a job is not open yet
See heating engineers, joiners and plumbers. Plumber cost and electrician cost in Cheshire are guides to other written prices. Fencing cost is unrelated work, linked only as another example of reading a quote. Leave any wiring to an electrician.
This page is general information, not professional or legal advice. QuoteZila does not check Gas Safe, WaterSafe, NFRC, NICEIC or other registrations against the register on your behalf: look them up yourself.
Before the joiner cuts timber, ask the engineer whether the door, the air path and the flue can still be seen with the door open, and write the answer on the quote. Keep the instructions somewhere you can find them on the day of a visit. If the kitchen units are being replaced in the same month, do not let the box disappear into that lump sum until the access question is answered. A sketch that shows the door swing, the worktop and the case is enough for both people to price the same corner.
Jobs you might post
These are examples, not taken from real job posts.
- "Kitchen boiler in Crewe, already in a corner. I want a joiner's price for a door, and I will book a Gas Safe engineer first to say whether the flue and the air path stay checkable. Do not move the pipe."
- "Nantwich. Instructions are missing. Please say if your visit can only be a look, and do not build anything on that visit."
- "Sandbach. I switched the boiler off because it smelt wrong. Gas Safe check only. No cupboard until you have finished."
Questions about boxing in a boiler
Is a cupboard the same job as working on the boiler?
A joiner can build a cupboard. That is not the same job as working on the boiler. HSE says anyone employed to work on a gas appliance in a home must be a Gas Safe registered engineer, competent for that work, with the competencies on the back of the ID card. Check the engineer on the Gas Safe Register or by calling 0800 408 5500. If the cupboard would mean moving the flue, the condensate pipe or the case, that is the engineer's line, priced separately. The cupboard is not, by itself, the gas work HSE is describing.
What does the inspection sheet say must be reachable?
Gas Safe Register's February 2026 factsheet lists, subject to access, ventilation, the flue or chimney, pressure-relief termination, and the condensate discharge pipe including its size, support and termination. Have the manufacturer's instructions ready. Without them the inspector may only look, and may not run operational checks. Ask the engineer whether your drawing still leaves those checks possible. Do not treat a silent quote as a yes.
What will an inspector not force their way into?
The factsheet says inspectors will not go onto a roof, into a loft without suitable access, or after pipework hidden in a wall or floor if getting to it would damage the home or be an unacceptable risk. A cupboard is not named in that list. The practical question to write on the job is whether the door still lets someone see the case, the air path and the pipe. Ask the engineer to write the gap they need, rather than guessing one.
What if I think the boiler is unsafe while the cupboard is planned?
HSE says it is illegal to use a gas appliance you suspect is unsafe. Turn it off and do not touch it until a Gas Safe registered engineer has checked it. HSE strongly advises that appliances, flues and pipework are serviced at least annually by a registered engineer. Do not ask a joiner to open the case, and do not look for a way to open the case yourself.
How do VAT and a deposit sit on a cupboard quote?
Citizens Advice says a quote is a fixed price and an estimate is a rough guess, and that you should collect written quotes from at least three traders where you can. If a deposit cannot be avoided, do not agree to more than 25%. GOV.UK says VAT registration applies when taxable turnover for the last 12 months goes over £90,000. A joiner and an engineer may be two businesses, so ask each whether VAT is in their total.
Does QuoteZila check the businesses?
No. We don't check insurance, qualifications or registrations, so please check these yourself before you hire. You can report a quote or a business from your job page.
Part of Cost guides. All services
Related trades
Cost guides
Related pages
- Chimney Liner Work: What to Ask First. A chimney liner in Cheshire depends on the fuel and the flue. This guide prints no installation price. It says who may do the work and what to name.
- Combi Boiler Cost: What Changes the Price. What goes into a combi boiler quote in Cheshire, from swaps and conversions to flues, controls and paperwork, and how to compare engineers' prices fairly.
Sources
- QZ1: QuoteZila product fact. QuoteZila public pricing line.
- QZ2: QuoteZila product fact. QuoteZila terms, customers.
- QZ5: QuoteZila product fact. QuoteZila coverage wording.
- S1: Gas Safe Register visit information for consumers, factsheet v6, Gas Safe Register. Accessed 2026-10-25. https://www.gassaferegister.co.uk/media/ykxo3tst/gas-safety-consumer-inspection-guide-factsheet-v6-final.pdf
- S2: Domestic gas FAQ, HSE. Accessed 2026-10-25. https://www.hse.gov.uk/gas/domestic/faqs.htm
- S3: Before you get work done on your home, Citizens Advice. Accessed 2026-10-25. https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/before-you-get-building-work-done/
- S4: Register for VAT, GOV.UK. Accessed 2026-10-25. https://www.gov.uk/register-for-vat