Expect roughly six to twelve weeks from your first phone call to a warm radiator. A smooth claim can wrap up in about a month. A messy one, held up by a missing letter or a busy surveyor, can drag past three months.
This year, the calendar matters more than the average. ECO4, the energy company programme behind almost every free boiler scheme in Great Britain, now closes on 31 December 2026. Every survey, plan and fitting has to be finished by then. Apply in October and you still have room. Leave it until December, and you probably won’t.
What Happens at Each Stage of the Wait?
Fitting the boiler is the quick part. Most of the delay sits in the middle, while paperwork passes between your installer, a retrofit assessor and the energy firm paying the bill.
| Stage | What happens | Rough time |
|---|---|---|
| 1. Eligibility check | The installer confirms your benefits, who owns the home and its energy rating | A few days |
| 2. Home survey | An assessor visits, measures each room and inspects the old boiler | 1–3 weeks to book |
| 3. Plan and funding | A coordinator writes the upgrade plan; the energy supplier approves the cost | 2–4 weeks |
| 4. Installation | Gas Safe engineers fit the boiler, plus any insulation in the plan | 1–2 days on site |
| 5. Sign-off | The new boiler gets registered and you receive the warranty | 1–2 weeks |
Treat these as typical ranges, not promises. Each installer runs its own queue.
Why Do Some Claims Stall?
So why do two neighbours who apply in the same week finish a month apart? One of these snags is usually to blame:
- Missing proof. No recent benefit letter, or a name that doesn’t match the property records.
- Insulation goes first. ECO4 improves the building before the heating. If your loft or walls need work, that job joins the plan and adds weeks.
- A boiler that still runs. The scheme rarely swaps a working boiler for a newer model on its own. Expect questions about its age, faults and efficiency.
- Landlord consent. Tenants need written permission from the owner before anything gets fitted.
- Busy installers. Every firm is racing toward the same closing date, so survey slots fill fast.
What Changes for Older Homeowners?
Pension Credit decides most cases. Receive it, and you’ll probably pass the benefit test for ECO4. The State Pension alone won’t qualify you.
Not on Pension Credit? Your council may still refer you through ECO4 Flex. This route lets local authorities widen the rules for residents on low incomes or with health problems made worse by a cold home.
Families arranging a boiler replacement for pensioners often make the calls for a parent. That works fine, as long as the homeowner signs the forms and is in for the survey. If the old boiler already struggles, start now. A breakdown in January, with the scheme shut, leaves far fewer options.
How Can You Speed Up Your Application?
You can’t control an installer’s diary. You can make sure your side never holds things up.
- Dig out your benefit award letter and photo ID before the first call.
- Check your home’s energy rating on the GOV.UK certificate register.
- Keep proof you own the property, or a signed note from your landlord.
- Offer several survey dates and grab the earliest slot.
- Ask the installer, in writing, whether they can finish before 31 December.
- Refuse any fee to “secure” a grant. Genuine ECO4 work costs eligible households nothing, and cold callers promising free boilers are a well-known scam.
What If You Miss the December Deadline?
There won’t be an ECO5. The government has moved that money into the Warm Homes Plan, due to start in 2027. Its full eligibility rules haven’t been published yet.
Until then, two routes stay open:
- Boiler Upgrade Scheme: £7,500 off a heat pump, but nothing toward a gas boiler.
- Warm Homes: Local Grant: council-run help with heating and insulation for lower-income homes.
If you think you qualify, book the assessment this month. In 2026, a late start is the easiest way to miss out.