A house that still has a working boiler can wait a week. A house on heating oil, with a grant that ends on 31 March 2027, cannot treat a leaflet as a design. This piece is the walk you do before anyone opens a tape measure. It is not a quote, not an eligibility decision, and not a substitute for the room-by-room heat-loss calculation an MCS designer has to produce.
If the heating will not fire at all, stop here and use the first-fire check. A lock-out, a gas smell or a wet patch under the case is a Gas Safe job tonight. A heat pump survey is a planned visit. If you already know you want a number, open plumbing and heating and ask whether the person is MCS-certified before you mention the grant.
Why this autumn is a different conversation
Two official changes sit on the same calendar. From 1 October 2026 to 31 March 2027, qualifying domestic electricity in Great Britain is charged at 0% VAT. That is the temporary zero rate in HMRC’s brief of 8 September 2026. Gas stays at 5%. Northern Ireland electricity stays on the reduced rate. DESNZ’s 26 August note puts the average electricity saving at about £45 a year. You do not apply. A heat pump still uses electricity. The cut does not make a badly insulated house cheap to run.
The other change is the Boiler Upgrade Scheme. GOV.UK: What you can get still lists £7,500 toward an air source (air-to-water) or ground source heat pump, £2,500 toward an air-to-air unit, and £5,000 toward a biomass boiler in limited cases. Until March 2027 you can get an extra £1,500 — £9,000 in total — if the property is heated by oil or LPG and has no mains gas connection. DESNZ’s 26 June 2026 announcement said that higher rate opened on 21 July 2026. Ofgem’s property-owner guidance matches those dates. Hybrid systems — a gas boiler paired with a heat pump — are not covered.
Households noticed. On 27 August 2026, DESNZ reported 8,150 scheme applications in July, 81% up on June, and said extra interest from heating-oil homes helped drive the record month. The installer still has to commission and install within 120 days of a properly made application, or that voucher fails. Booking a survey in September is not the same as having a commissioned unit. Diaries fill as the first frost arrives.
If you are on mains gas, the standard £7,500 figure is the one to read, not the £9,000 oil leaflet. If you are a tenant, the owner has to make the claim. Social housing and most developer new-builds are outside the scheme on GOV.UK.
A walk you can do tonight
You are collecting facts for a phone call, not designing the system. Write them down. An installer who has to guess every measurement will either oversize the unit or decline the job.
- Open the loft hatch. Note how deep the quilt looks at the joists and whether the hatch itself is insulated. Photograph a ruler if you have one. Do not walk the joists in socks. Thin loft insulation is common and is a quote for insulation, not an automatic “no”.
- Walk every heated room. Write single-panel or double-panel for each radiator, and whether a towel rail is the only heat in a bathroom. A heat pump usually runs cooler water than a gas boiler. Some panels will be fine. Some will not. The calculation decides, not a shop label.
- Find the hot-water cylinder, or confirm you have a combination boiler and no cylinder cupboard. An air-to-water heat pump that also makes hot water normally needs a cylinder. A tiny airing cupboard can force a different layout or a different product. Measure the cupboard, do not guess.
- Stand in the garden or side return and pick one place an outdoor unit could sit on the ground, with air on the intake and exhaust sides and room for someone to service it. Note the nearest neighbour window and whether that wall fronts a road.
- Open the consumer unit. Photograph the main switch rating and how many spare ways you have. Do not remove the cover if it is a sealed plastic lid you cannot refit. A heat pump often needs a dedicated circuit. That is an electrician’s job, not a weekend add-on.
- Find the latest Energy Performance Certificate if you have one, and the boiler make and model. You can still be eligible if you have already had insulation funding. You cannot use the scheme to replace an existing low-carbon system.
The heating power calculator helps you describe floor area on that call. The heat-pump savings tool is a browser estimate, not a running-cost guarantee. Neither replaces a heat-loss survey.
Radiators versus a heat-loss survey
MCS design standard MIS 3005-D is what a certified designer works to. For a system that must cover the whole heating load, it requires a room-by-room heat-loss calculation and an outdoor unit that can meet that load at the design outdoor temperature. The boiler badge in the cupboard is not that number. A 24 kW combination boiler was sized for fast hot water as much as for radiators. Copying it onto a heat pump is how houses end up noisy, expensive, or both.
What you can see tonight is still useful. Single-panel radiators in large north rooms are the usual upgrade candidates. A house that already has double panels and a reasonable loft is often closer than the owner thinks. Underfloor heating on the ground floor can work at low flow temperatures. A conservatory with no insulation and a single radiator is often left off the heat-pump circuit rather than used to size the whole machine.
| What you notice | What it usually means | What it does not mean |
|---|---|---|
| Loft quilt well below the joists | Heat loss will be higher until the loft is topped up | That the survey is pointless. Insulation can be quoted first or with the pump |
| Most radiators are slim single panels | Some rooms may need larger emitters at a lower flow temperature | That every radiator in the house must be ripped out |
| Combination boiler, no cylinder | Hot water storage has to be found or the design changes | That an air-to-air unit is automatically the answer. That grant is £2,500 and a different system |
| One bedroom always colder than the rest | A valve, air, or a local fabric problem | That a heat pump will fix it without the bleed check or a plumber |
| Solid walls, original sash windows, no cavity | The heat-loss figure will be higher and the running cost less kind | That the house is banned. The designer still has to calculate it |
Ask to see the written heat-loss sheet and the radiator schedule before you sign. If the quote only names a brand and a grant discount, it is not a design. Radiators, a consumer-unit upgrade, a cylinder and making good can sit outside the GOV.UK figure. For pounds, use the cost notes. This page will not invent a typical install price.
Outdoor space, noise and planning
An air source unit needs air, a firm base, condensate drainage and access. A yard that is only a bin store may still work. A first-floor flat with no exclusive outdoor space often will not. Leasehold and a shared garden are legal questions as much as technical ones. The surveyor should say so early.
In England, many domestic air source installations can proceed as permitted development if every limit on the Planning Portal air source page is met. The 29 May 2025 amendments removed the old one-metre boundary ban, raised the house unit limit to 1.5 cubic metres (0.6 cubic metres on a block of flats), and allow two units on a detached house. Pitched-roof mounting is not permitted development. Listed buildings and scheduled monuments are outside those rights. Conservation areas and highway-facing walls have extra placement rules. Rights can also be removed by an Article 4 direction. Wales, Scotland and Northern Ireland keep their own rules; MCS still points those nations at MCS 020 rather than MCS 020a.
The sound test for England permitted development is MCS 020a. The installer calculates a level at neighbouring habitable-room doors and windows. A common pass mark discussed with that standard is 37.0 dB(A) at each assessment position. You cannot do that sum with a phone app over the fence. You can note how close the neighbour’s bedroom window is, and whether a side return is a wind tunnel between two walls. If the calculation fails, the options are a different model, a different place, or a planning application — not “turn it down at night” written on a quote.
Do not commission a slab or cut a hole in a wall because a salesperson pointed at a corner. Placement, noise and planning sit with the designer. A listing on this site is a name and a number, not permission from the council.
What the grant is, and what this page is not
You do not apply on GOV.UK as a homeowner form. How to apply is: contact MCS-certified installers, confirm they think you are eligible, agree a quote, and let that installer apply to Ofgem. The grant is a discount on the quotation and the invoice. Ofgem may write to you or visit. One grant applies per property. Self-builds can still meet the £7,500 route in the cases GOV.UK lists; Ofgem’s owner guidance says they are not eligible for the £9,000 oil and LPG uplift.
This directory’s grant notes are the place for amounts, Gas Safe versus MCS, and who the cards actually name. None of the profiles here show MCS. Three London plumbing cards mention heat pumps. Ask the person who answers whether they are MCS-certified and whether they will make the Ofgem claim. If they cannot, the GOV.UK figure does not attach to that visit.
Low-income households in England may have a different door: the Warm Homes: Local Grant, delivered by the local council, which can fund insulation and an air source heat pump where the council has money and the home is privately owned with an EPC of D to G. Household income is usually £36,000 a year or less, with other routes through benefits or certain postcodes. That is not the Boiler Upgrade Scheme, and this site does not decide either one.
When to stop guessing and call
The homeowner walk ends when you have a page of notes, or when one of these is already true.
- You smell gas, hear a hiss you cannot place, or the carbon monoxide alarm sounds. Leave, call the Gas Emergency Service on 0800 111 999, and do not use electrical switches on the way out.
- The boiler has failed and the house is without heat or hot water. That is a repair or a replacement conversation first. Use the October first-fire guide and a Gas Safe engineer. Do not wait for a heat-pump survey while the house is cold.
- You are a tenant. Tell the owner what you saw. You cannot sign a Boiler Upgrade Scheme claim on a property you do not own.
- The only outdoor space is shared, listed, or a pitched roof. That is a planner and a lease question, not a weekend slab.
- Someone offers to “size it from the boiler badge” or to claim the grant without an MCS number. Put the phone down.
Anyone doing gas work as a business must be on the Gas Safe Register. Anyone claiming the Boiler Upgrade Scheme must be MCS-certified. Those are different registers. A mark on a profile here only means the field is present. It is not a badge this site sells.
What to have on the call
Have the fuel you use now (mains gas, oil, LPG or electric), whether a gas pipe actually enters the house, the boiler make and model, cylinder or combination, a rough loft depth, a note on single versus double radiators, one proposed outdoor spot, and whether the building is listed or in a conservation area. Say you want a heat-loss survey, not a brochure visit. Ask whether they are MCS-certified for heat pumps, whether they will make the Ofgem claim, how they treat the 120-day install window, and whether the first figure is plus VAT after the grant.
This site does not email the business. Open the directory — for example plumbing in London or plumbing in Manchester — and use the number on the card. If the job is a consumer-unit upgrade after the survey, open electrical the same way.
Questions before you book
These answers stay inside what GOV.UK, Ofgem, HMRC and the Planning Portal have already published. They are not a survey.
Does a thin loft mean I cannot have a heat pump? No. It means heat loss will be higher until the loft is improved. The designer still calculates the house as it is, and can quote insulation with the pump. Do not buy random rolls and block the eaves vents before anyone has looked.
Do I apply for the Boiler Upgrade Scheme myself? No. You find an MCS-certified installer, agree a quote, and they apply to Ofgem. The grant is taken off what you pay. Ofgem may contact you to confirm the installer is acting for you.
Is Gas Safe the same as MCS? No. Gas Safe is gas work. MCS is the certification GOV.UK and Ofgem expect for this grant. Ask for the card that matches the work.
Will this site send my survey request? No. You open a list and place the call. Nobody here emails a tradesperson on your behalf.
Need a number after the walk?
Open plumbing and heating, pick the city, and ask whether the business is MCS-certified. You place the call.