Boiler checks before buying a house: what surveys miss

Do home surveys test the boiler?

Most standard home surveys do not test the boiler. A RICS Home Survey inspects the visible parts of the heating and gas services but does not test the installations or appliances in any way, so a survey alone will not confirm the boiler is safe or in good working order. Before you buy, commission a separate Gas Safe boiler inspection and ask the seller for the service history and any gas safety record.

Below we cover what a survey will and won't check, the extra checks worth booking, the questions to put to the seller, and how to line up cover for the day you complete. Last updated July 2026.

The scope comes straight from RICS. Its Home Survey standard states that the surveyor 'does not perform or comment on design calculations or test the service installations or appliances in any way', and instead visually inspects what can be seen and may ask the occupier to switch the heating on. What a surveyor can flag is limited to the visible: staining or corrosion around visible pipe joints, a boiler casing in poor condition, or a flue terminal that looks badly positioned. Those are useful pointers, but they are observations, not confirmation that the boiler fires and burns safely. A visual look is not a test, which is why a dedicated boiler inspection is worth the extra cost on a purchase.

What a home survey checks, and what it does not

Your boiler checklist before buying

Five checks worth making before you exchange.

• Service history: ask for dated service records or receipts. A boiler serviced every year by a Gas Safe registered engineer is a good sign; no paperwork is a warning flag.
• Gas safety record (CP12): if the property was ever let, the seller should hold a Landlord Gas Safety Record. A buyer cannot legally demand one, but it is fair to ask for the most recent copy.
• Warranty and registration: find out the make, model and install date, and whether any manufacturer warranty is still valid and can transfer to you.
• Age from the data plate: the serial or data plate on the boiler usually shows the manufacture date, which tells you roughly how much life is left.
• Flue and condensate visual: look at the flue terminal outside and the condensate pipe run for obvious damage, poor routeing, or an external run that could freeze in winter.

What does a Gas Safe boiler inspection cover?

A Gas Safe boiler inspection is the hands-on check a survey is not. A Gas Safe registered engineer will confirm the boiler fires and runs, check the gas pressure and flue, look for signs of leaks or corrosion, and confirm the appliance is burning safely. It is the check that tells you whether the boiler is sound, not just present.

You can usually book this before completion, with the seller's cooperation for access. It is a small cost against the price of a boiler that fails soon after you move in, and it pairs naturally with asking for the service history and warranty paperwork.

If the inspection turns up a fault, you can use the estimated repair or replacement cost to renegotiate the asking price before you exchange, a common and reasonable step.

What should you ask the seller?

Ask for the boiler's make, model and age, its full service history, and any manufacturer warranty details. Ask when it was last serviced and whether there are any known faults. If the home was previously rented, ask for the most recent CP12 gas safety record.

What if the boiler is old or has been condemned?

An older boiler is not a dealbreaker, but it changes the maths. Cover is still available for older boilers, usually with a lower annual claim limit: the boiler module allows up to £500 of claims a year for boilers under 7 years old and up to £200 a year for boilers 7 years and older, so you may want to budget for a future replacement. If a boiler has been condemned, an engineer will have labelled it At Risk or Immediately Dangerous, and it must not be used until it is repaired or replaced. Never switch a condemned boiler back on, and get a Gas Safe registered engineer to advise.

If you ever smell gas or suspect carbon monoxide, call the National Gas Emergency Service on 0800 111 999.

Prefer it covered before it breaks?

Once you complete, a boiler module means a winter breakdown in your new home is handled up to your plan limit: choose only the cover you want and see your price in the online builder. Call-outs run Monday to Friday, 08:00 to 18:00. A £95 call-out fee applies in defined cases set out in the plan terms, including the first 30 days, and a 12-month agreement period begins once you use a service. A service plan, not insurance. Questions? Call 0333 772 6247.

Boiler checks before buying a house: your questions answered

Related links

• Boiler cover when moving house
• Cover for older boilers
• Should you repair or replace your boiler?
• Boiler condemned? What to do
• UK boiler repair and replacement costs
• CP12 gas safety certificate: cost and rules
• How to check a Gas Safe engineer's ID card
• Is boiler cover worth it?
• Boiler & central heating cover
• RICS home surveys: what a survey covers