Plumbing and heating engineer insurance is cover for a trade whose claims tend to share three causes: water, heat and gas. A compression fitting that weeps for three weeks behind a kitchen unit. A blowlamp used near a joist end that smoulders after you've left. A boiler commissioned without the flue checked properly. Most of the money in plumbing claims goes on property damage that happens after you've packed up, so the cover that matters most is the part of your public liability that responds to completed work.

This guide is for sole trader plumbers, heating engineers, gas engineers, and small plumbing and heating firms working on homes, rentals and commercial buildings. It's organised around how claims actually arise in the trade and what an insurer will ask you about each one: heat work, escape of water, gas work, design and sizing, and the people you employ.

For the general picture of trades insurance across all trades, start with our contractor insurance UK guide. For the detail of each cover, we have separate guides to public liability and employers' liability. If you also do electrical work, our electrician insurance guide covers Part P and the electrical schemes. This page sticks to plumbing and heating.

The law described here is for England and Wales unless stated otherwise. The gas safety regulations apply across Great Britain. Scotland and Northern Ireland have their own building standards and water byelaws.

Want to talk through your cover? Speak to us. We place plumbing and heating risks with the insurers on our panel that write the trade, and charge a flat 10% broker fee.

Start with the work you do, not the policy names

Two plumbers can both call themselves "plumbing and heating" and present completely different risks to an insurer. Underwriters price and accept the trade on what you actually do, so the first job is describing it accurately. Here's how the main types of work tend to change the questions you're asked.

If you do several of these, say so. Under-describing the trade is the most common reason a plumbing claim gets argued about. A policy written for "plumbing (no gas work)" is the wrong policy for someone who also fits boilers.

Heat work: the condition most likely to decide a fire claim

Plumbers use more open flame than most trades. Soldering capillary fittings with a blowlamp is routine, and that makes heat work a central underwriting question. Most public liability policies for plumbing and heating trades contain a heat work condition, sometimes called a "hot work" condition or warranty. If a fire happens while you're using heat and you didn't follow the condition, the insurer may refuse the claim or reduce it.

The wording varies, so read your own. Typical requirements include:

• moving combustible materials away from the work area, or protecting them with non-combustible covers or shields

• having a suitable fire extinguisher immediately available while using heat

• not using heat in certain places, such as roof voids or near thatch, or only with extra precautions

• inspecting the area once the work is finished, and continuing to check it for a set period afterwards (often 30 or 60 minutes)

• in some wordings, using a written hot work permit on commercial sites

Two practical points make the difference when a claim happens.

The fire watch period. Timber smoulders. A fire that starts in the hour after you used a blowlamp is precisely the situation the condition is designed for. If you can't stay for the period the condition requires, you're not compliant, however careful the soldering was.

Evidence. Insurers deal with heat-work fires by asking what you did. A habit of photographing the work area, the heat-resistant mat and the extinguisher, and noting the time you left, turns a dispute into a straightforward claim.

If most of your work is press-fit or push-fit and you rarely use flame, tell the insurer. Some will treat a low-heat-work business differently, but only if the proposal says so.

Escape of water: who pays when your joint fails

Escape of water is the claim most plumbers will eventually face. It plays out in three ways, and each lands in a different place.

1. Damage to the customer's property or a neighbour's property after you leave. A joint you made fails and water comes through the ceiling below. This is third-party property damage caused by your completed work. It falls under the products and completed work section of your public liability policy, not the main public liability section. Check that section is included, and check the limit. Many policies give one aggregate limit for products and completed work in a period of insurance, not a limit per claim.

2. The cost of putting your own work right. Most public liability policies exclude the cost of repairing or replacing the faulty work itself, often called a faulty workmanship exclusion. The insurer pays for the damaged ceiling, flooring and contents. You pay for remaking the joint and replacing the fitting. Read how widely the exclusion is drafted. Some wordings exclude only the defective part. Others exclude the whole of the work you did.

3. Damage during the job. You drain down, a valve doesn't hold, and the floor gets wet while you're still on site. That's the main public liability section. If the damage is to the works you're installing and haven't handed over, it may instead be a contract works question (see below).

The customer's own home insurance may also respond to escape of water, and their insurer may then pursue you to recover what it paid. That recovery claim is still a claim against your public liability cover, even if the customer never complains to you directly. Notify your insurer as soon as you hear about it.

What water regulations add

The Water Supply (Water Fittings) Regulations 1999 apply in England and Wales. Regulation 4 says every water fitting must be of an appropriate quality and standard, suitable for how it's used, and installed, connected, altered, repaired or disconnected in a workmanlike manner.

Regulation 5 requires notice to, and consent from, the water undertaker before certain work starts. The listed work includes:

• a bath with a capacity of more than 230 litres, measured to the centre line of overflow

• a bidet with an ascending spray or flexible hose

• a pump or booster drawing more than 12 litres per minute connected to a supply pipe

• a reverse osmosis unit, and some water treatment units

• a reduced pressure zone valve assembly or similar device for fluid category 4 or 5

• a garden watering system unless it's designed to be operated by hand

• extending or altering the water system on premises other than a house

Some of this work is exempt from notification when an approved contractor does it. The undertaker has ten working days to respond.

None of that is insurance law. It's the standard against which a claim is judged, though. If a loss adjuster finds an installation didn't follow the regulations, the liability argument against you gets stronger.

Gas work: registration, competence and what the insurer checks

Gas Safe registration

Regulation 3 of the Gas Safety (Installation and Use) Regulations 1998 says no one may carry out work on a gas fitting unless they're competent to do so. Regulation 3(3) goes further: no employer may allow employees to work on a gas fitting or service pipework, and no self-employed person may do that work, unless the employer or self-employed person belongs to a class of persons approved by the Health and Safety Executive. In practice, that's the Gas Safe Register. Regulation 3(7) makes it an offence to falsely pretend to be a member.

HSE explains that registered engineers carry a Gas Safe ID card showing the types of work they're qualified to do and whether their qualifications are up to date. This matters for insurance, because underwriters ask which gas categories you hold. If you're qualified for domestic natural gas but take on commercial catering or LPG work outside your categories, you're outside your competence. Expect the insurer to treat that very seriously.

Some insurers write gas work only if the business itself is Gas Safe registered, not just one engineer. If you subcontract gas work to a registered engineer, tell your insurer and keep their registration details on file for each job.

Installation, commissioning and checks

Regulation 26 sets out safety precautions when installing and working on gas appliances. Among other things, nobody may install an appliance unless it can be used without danger, and after working on an appliance the engineer must immediately examine the effectiveness of the flue, the supply of combustion air, the operating pressure or heat input (or combustion performance where checking those isn't reasonably practicable), and its safe functioning. Any defect has to be reported to the responsible person.

Most serious gas claims turn on these steps. Your commissioning record and benchmark paperwork are the evidence that you did them.

Unsafe situations

Regulation 34(3) says anyone working on gas fittings who knows or has reason to suspect that an appliance can't be used without danger must take all reasonably practicable steps to inform the responsible person for the premises and, where different, the owner of the appliance. Gas Safe Register's industry unsafe situations procedure sets out how registered engineers classify and deal with what they find.

From an insurance angle, the record you leave of an unsafe situation is your defence if something goes wrong later. Write it up, give a copy to the customer, and keep your own.

Reporting to HSE under RIDDOR

Regulation 11(2) of RIDDOR 2013 requires a Gas Safe registered business (the regulations say "approved person") to report to HSE within 14 days where it has enough information to decide that the design, construction, installation, modification or servicing of a gas fitting is or could have been likely to cause death, loss of consciousness or hospitalisation because of gas leakage, incomplete combustion or inadequate removal of combustion products.

That report is separate from notifying your insurer. If you make one, tell your insurer as well. A RIDDOR report about someone else's dangerous installation is often a sign of a dispute to come, even if your own work isn't the cause.

Landlord gas safety checks

Regulation 36 requires landlords to have relevant gas appliances and flues checked for safety at intervals of no more than 12 months, keep a record for two years, and give tenants a copy within 28 days of the check. If you do these checks, you're producing a document that a landlord, tenant, letting agent or local authority will rely on.

A claim arising from a check you carried out may be about injury or damage, which falls under public liability, or about financial loss from reliance on an inaccurate record, which is a professional indemnity question. Some trade public liability policies include limited cover for inspection and certification work. Others exclude it. If landlord checks are a meaningful part of your work, ask how the policy treats them. Our guide to landlord gas safety certificates and insurance covers the landlord's side of the same document.

Building Regulations: self-certifying heating work

Installing a heat-producing gas appliance, or a heating or hot water system or its controls, is building work under the Building Regulations 2010 in England. Wales has its own amended version of the same regulations. Instead of notifying building control before each job, the work can be self-certified by a person in the right category under Schedule 3. For heat-producing gas appliances, that's a person who belongs to the class approved under regulation 3 of the gas safety regulations, the Gas Safe Register. For heating and hot water systems, it can also be a member of a relevant competent person scheme.

The government's list of competent person schemes includes, for heating and hot water systems, schemes such as APHC, BESCA, Blue Flame Certification, Certsure, HETAS, NAPIT and OFTEC, as well as Gas Safe Register. For oil-fired appliances and tanks, it lists APHC, BESCA, Blue Flame Certification, Certsure, NAPIT and OFTEC. The government notes that Gas Safe Register isn't technically a competent person scheme, but its installers have the same responsibilities in practice.

For unvented hot water, Schedule 1 Part G3 requires a hot water system with a storage vessel to include precautions to stop the stored water ever exceeding 100°C and to discharge safety devices safely to where the discharge is visible but not a danger. The government's approved document for Part G sets out ways of meeting that, including guidance on installer competence.

Why this matters to an insurer:

• Some schemes require a minimum level of public liability cover as a condition of membership. Check the scheme rules and make sure your limit meets them.

• Notification isn't optional. A job that should have been notified and wasn't is harder to defend if the installation later causes damage.

• When you sell a house or a landlord re-lets, the absence of a compliance certificate can lead to claims for costs against the installer. These are usually financial claims, not property damage, and may not fall under public liability at all.

Design, sizing and professional indemnity

Most plumbers never need professional indemnity insurance. The ones who do usually find out when a customer says the new system doesn't work.

PI covers your legal liability for financial loss caused by your professional advice, design or specification. It's different from public liability, which covers injury and damage. A system that works but underperforms doesn't damage anything. It just costs the customer money to fix.

Plumbing and heating work where PI becomes relevant includes:

• heat loss calculations and heat pump system design

• boiler and radiator sizing for a whole-house system you've specified

• designing commercial heating, hot water or plant room systems

• specifying unvented or mains-pressure systems where you choose the equipment

• issuing reports or certificates others rely on for a financial decision

• design-and-build work under a contract that makes you responsible for design

Heat pumps

Low-carbon heating pushes more plumbing businesses towards design responsibility. A heat pump installation depends on accurate heat loss calculations and emitter sizing, and the claim if it's wrong is typically that the house can't be kept warm or running costs are much higher than expected. Those are financial loss claims. If you design the system, or if a subcontract makes you responsible for a design someone else did, look at PI.

Refrigerant work is a separate issue. Government guidance on fluorinated gases says that if you use or service equipment containing F gas, you may need qualifications and company certification to work with it. Many heating engineers subcontract refrigerant work on split systems. If you do the work yourself, the insurer will ask whether you and the business hold the right certification. Our professional indemnity insurance guide explains how PI works in detail.

Your people: employees, labour-only and bona fide subcontractors

The Employers' Liability (Compulsory Insurance) Act 1969 requires most employers to insure against liability for injury and disease to their employees arising from their work. The Employers' Liability (Compulsory Insurance) Regulations 1998 set the minimum at £5 million for any one occurrence. A sole trader with no employees doesn't usually need it.

Plumbing businesses have three particular EL questions.

Apprentices. An apprentice is normally an employee and needs to be covered. Tell the insurer about apprentices and their ages. Some insurers restrict work at height or with heat for younger workers.

Labour-only subcontractors. If you engage someone who works under your direction, uses your materials and tools, and doesn't carry their own insurance, they may be treated as your employee for EL purposes, whatever their tax status. Insurers often require labour-only subcontractors to be declared in wageroll or headcount.

Bona fide subcontractors. A properly independent subcontractor with their own public liability cover is usually treated differently. Some policies require you to check that subcontractors hold their own PL to a set limit, and can reduce cover if you don't. Keep copies.

Health hazards matter for EL too. Asbestos is the obvious one for anyone working on older pipework, boilers, flues, cisterns and lagging. The Control of Asbestos Regulations 2012 require an employer not to carry out work in premises that's liable to disturb asbestos unless it has assessed whether asbestos is present, or assumes it is (regulation 5). Regulation 10 requires information, instruction and training for employees who are, or may be, exposed. Asbestos awareness training is a common insurer question for plumbing trades.

Legionella is another water-related responsibility, though the duty mostly sits with the person in control of the premises. HSE publishes guidance on landlords' responsibilities for legionella risk. If you carry out water hygiene work for commercial clients, tell your insurer. It's a specialist activity that some trade policies don't include automatically.

Contract works, tools and the van

Contract works. This covers the work in progress and materials on site before handover: a part-installed system damaged by flood, or a plant room fit-out damaged by fire. On domestic jobs, plumbers often go without it. On larger jobs, main contractors and commercial clients may require you to insure the works or confirm you're covered under their project policy. Check the contract.

Tools and equipment. Press tools, pipe freezers, drain cameras, flue gas analysers and leak detection equipment are expensive. Theft from vans is the usual claim. Most tools policies include conditions about overnight security, for example tools left in a van overnight being covered only if the van is locked and alarmed, or not covered at all. Check what applies to how you actually work.

Calibration. Flue gas analysers need regular calibration. That's not an insurance requirement, but an out-of-date calibration certificate gives a loss adjuster an easy point to make after a carbon monoxide claim.

The van. Motor insurance is compulsory for using a vehicle on a road. Make sure your van policy covers business use for your trade and carrying tools and materials. Goods-in-transit cover for stock is often separate.

How long claims can follow you

Plumbing and heating claims can arise long after the job.

Under the Limitation Act 1980, a claim for breach of a simple contract generally has to be brought within 6 years of the breach (section 5). For negligence causing latent damage, section 14A allows a claim within 3 years of when the claimant knew, or could reasonably have known, the relevant facts, if that's later than 6 years from when the damage happened.

For work in connection with providing a dwelling, the Defective Premises Act 1972 imposes a duty to see that work is done in a workmanlike or professional manner, with proper materials, so the dwelling is fit for habitation when completed (section 1). The Building Safety Act 2022 (section 135) extended the limitation period for claims under section 1 to 15 years where the right of action accrues on or after 28 June 2022, and to 30 years, retrospectively, where it accrued before that date. That's more relevant to new-build and conversion work than to replacing a radiator, but plumbing and heating firms working on new homes should be aware of it.

In addition, under the Consumer Rights Act 2015, a contract to supply a service to a consumer is treated as including a term that the trader must perform the service with reasonable care and skill (section 49). Under section 50, what you say about the service can become a binding term.

The insurance point: liability policies normally respond to claims based on when the injury or damage happened, while PI responds to claims made during the period of insurance. If you retire or close the business, ask about run-off cover for PI and how your public liability will deal with later claims from completed work.

Six claim scenarios from plumbing and heating work

These are illustrations, not real claims. The outcome in any case depends on the wording and the facts.

1. The ceiling that came down a month later. A plumber fits a new bathroom in a first-floor flat. Five weeks later, a compression joint behind the bath panel gives way and the ceiling of the flat below collapses. The neighbour's insurer pays and pursues the plumber. The products and completed work section of public liability deals with the damage to the flat below. The plumber pays to remake the joint because of the faulty workmanship exclusion.

2. The smouldering joist. A heating engineer solders a pipe joint under the floor of a Victorian terrace, stays for fifteen minutes, and leaves. Forty minutes later, smoke appears. The policy's heat work condition requires an hour's fire watch. The insurer questions the claim. The engineer's notes and photos help on the other conditions, but not on the fire watch.

3. The boiler outside the engineer's categories. A Gas Safe registered engineer qualified only for domestic natural gas work agrees to repair a commercial catering range in a café kitchen. Carbon monoxide builds up and a member of staff is taken to hospital. The engineer wasn't competent for that category of work. The insurer argues the claim falls outside the policy description and its conditions. The legal exposure is serious too.

4. The heat pump that couldn't heat. A plumbing firm designs and installs a heat pump in a 1930s semi. The heat loss calculation underestimates the heat demand, and the house won't get above 17°C in January. Nothing is damaged. The customer claims the cost of bigger radiators and higher running costs. Public liability doesn't respond. Professional indemnity would, if the firm had it.

5. The landlord's record. A gas engineer carries out an annual landlord check and records an appliance as safe. Two months later, a tenant complains of headaches and a second engineer finds a blocked flue. The tenant claims against the landlord, and the landlord claims against the first engineer. Depending on whether anyone was injured and how the policy treats inspection work, that's public liability, PI, or a gap.

6. The apprentice and the old lagging. A small heating firm strips out an old boiler and pipe lagging in a 1960s house. No one checks for asbestos. Years later, a former apprentice is diagnosed with an asbestos-related condition. Employers' liability is the cover that applies, under the policy in force when the exposure happened. That's why EL certificates and policy records need keeping long after the job.

What to have ready when you ask for a quote

You'll get a better outcome if you can answer the insurer's questions accurately at the start:

• your legal status (sole trader, partnership, limited company) and how long you've traded

• your Gas Safe registration number and the categories you hold, and any other scheme memberships

• an honest split of your work: general plumbing, gas, oil, unvented, heat pumps, commercial, drainage

• how much heat work you do, and whether you mostly use press-fit or flame

• turnover, and the most you've earned from one contract

• employees, apprentices, labour-only and bona fide subcontractors

• any design, sizing or certification work

• the public liability limit your scheme, customers or main contractors require

• tools, equipment and van details

• claims in the last five years, including any you paid yourself

For a wider view of trade cover, see our contractor insurance UK guide.

Frequently asked questions

Do plumbers need insurance by law?

Only employers' liability is a legal requirement, and only if you have employees, with a minimum of £5 million under the 1998 regulations. Public liability isn't legally required, but competent person schemes, many customers and almost every main contractor will expect it.

Does public liability cover a leak from my work?

Usually, for damage to other people's property, through the products and completed work section, if your policy includes it. It typically won't pay for redoing your own faulty work.

What is a heat work condition?

A condition in your liability policy that sets out precautions when using heat, such as blowlamps, soldering and brazing equipment: clearing combustibles, having an extinguisher ready, and watching the area for a set period after finishing. Not following it can affect a fire claim.

Do I need professional indemnity as a plumber or heating engineer?

Not for routine installation and repair. Consider it if you design systems, calculate heat loss, size heat pumps or commercial plant, or produce reports and certificates others rely on for financial decisions.

Does my insurance cover gas work if I'm Gas Safe registered?

Only if your policy includes gas work, and generally only within the categories on your Gas Safe registration. Tell the insurer what types of gas work you do and keep your registration up to date.

Is a landlord gas safety check covered by my public liability insurance?

It depends on the wording. Injury or damage caused by your work is a public liability matter. A claim for financial loss because someone relied on your record may be a professional indemnity matter, and some trade policies exclude inspection and certification work.

I subcontract to bigger plumbing firms. Do I need my own insurance?

Usually, yes. Main contractors normally require their subcontractors to hold their own public liability to a stated limit. If you work as labour-only under their direction, check whether their employers' liability covers you, and keep your own tools cover.

Does tools insurance cover theft from my van overnight?

Only if your policy includes it, and usually subject to conditions such as the van being locked, alarmed or parked in a certain place. Some policies exclude overnight theft from vehicles altogether.

Speak to us about plumbing and heating cover

Tell us what you actually do: the mix of plumbing, gas, unvented, heat pump and commercial work, how much heat work it involves, and who works with you. We'll match that to the right covers and place it with the insurers on our panel that write plumbing and heating trades. Speak to us.

Meshed is a trading name of Mesh'd Limited, authorised and regulated by the Financial Conduct Authority (FRN 1033248). We charge a flat 10% broker fee. This guide is general information, not legal advice.