Your boiler's making weird noises. Do you call a plumber or a heating engineer? Here's how to know exactly who to ring (and avoid paying for the wrong person).
You're standing in front of your radiator, which is stone cold despite the heating being "on." You Google "plumber near me" and get hundreds of results. Then you search "heating engineer" and get different results. Wait – aren't they the same thing? Should you be ringing a plumber? Or a heating engineer? Or is there someone else entirely you need?
If you're confused, you're absolutely not alone. The overlap between plumbers and heating engineers baffles most homeowners, and it's easy to understand why. They both work with pipes, they both deal with water, and they both seem to sort out problems in your house when things go wrong. But there are crucial differences, and calling the wrong one can cost you time, money, and a lot of frustration.
This guide will demystify the whole thing. By the time you've finished reading, you'll know exactly who does what, when you need which professional, what qualifications to look for, and how to avoid the cowboys who claim to do everything whilst being properly qualified for nothing.
What Actually Is a Plumber?
Let's start with the basics. A plumber is someone who works with water systems in your property – getting clean water to where you need it and taking waste water away.
What Plumbers Actually Do
Water supply: Installing and maintaining pipework that brings fresh water into your property and distributes it to:
- Taps and toilets
- Showers and baths
- Washing machines and dishwashers
- Outside taps
- Any other water outlet
Drainage and waste: Installing and maintaining pipes that take dirty water away from:
- Sinks and basins
- Toilets and bidets
- Showers and baths
- Washing machines
- Drainage systems
Bathroom installations: Fitting complete bathroom suites including:
- Baths, showers, and shower enclosures
- Toilets and bidets
- Basins and vanity units
- Taps and mixers
- Waste systems
Kitchen plumbing: Installing and maintaining:
- Kitchen sinks
- Taps and mixer taps
- Dishwasher connections
- Washing machine connections
- Water filters
General plumbing repairs:
- Fixing leaks (taps, pipes, joints)
- Clearing blockages
- Replacing worn parts
- Repairing or replacing stopcocks
- Dealing with water pressure issues
- Emergency burst pipe repairs
What plumbers typically don't do (unless they've got additional qualifications):
- Work on gas boilers
- Install or repair central heating systems that involve gas
- Service gas fires
- Anything involving gas at all
That last point is crucial, and we'll come back to it in a moment.
Plumber Qualifications
Here's something important: in the UK, you don't legally need specific qualifications to call yourself a plumber and work on water systems (though you absolutely should have them).
Typical plumber qualifications:
- Level 2 Diploma in Plumbing Studies
- Level 3 Diploma in Plumbing and Domestic Heating
- NVQ Level 2 and/or 3 in Plumbing
- City & Guilds certifications
Additional useful qualifications:
- Unvented Hot Water Systems (G3 qualification) – for working on modern hot water cylinders
- Water Regulations – ensures they won't accidentally contaminate your water supply
- CIPHE or APHC membership (professional bodies)
Good plumbers will happily show you their qualifications. If someone can't produce any paperwork, that's a red flag.
What Actually Is a Heating Engineer?
A heating engineer specialises in heating systems – particularly those involving gas. This is where things get a bit more technical and, frankly, a bit more serious from a legal standpoint.
What Heating Engineers Actually Do
Gas boiler work:
- Installing new boilers (combi, system, regular)
- Servicing boilers annually
- Repairing boiler faults
- Diagnosing and fixing error codes
- Replacing boiler components
Central heating systems:
- Installing radiators
- Balancing heating systems
- Fitting thermostatic radiator valves
- Installing and programming thermostats and controls
- Power flushing systems
- Repairing or replacing circulation pumps
Gas appliance work:
- Installing gas fires and gas cookers
- Servicing gas appliances
- Conducting landlord gas safety checks
- Issuing gas safety certificates
Hot water systems:
- Working on hot water cylinders
- Installing and maintaining unvented systems
- Sorting out hot water problems
What they don't typically do (unless they're also qualified plumbers):
- Bathroom installations
- General water pipe repairs
- Drainage work
- Waste system installations
Heating Engineer Qualifications: The Legal Bit
This is critical, so pay attention: anyone working on gas in the UK must be Gas Safe registered. This isn't optional, it's not a nice-to-have, it's the actual law.
Gas Safe Registration: Under the Gas Safety (Installation and Use) Regulations 1998, it's illegal to work on gas appliances unless you're registered with Gas Safe Register. Breaking this law can result in:
- Fines up to £20,000
- Prison sentences up to 6 months
- Manslaughter charges if someone dies (life imprisonment possible)
For you, the homeowner: Using an unregistered person for gas work invalidates your home insurance and you can face legal consequences too if something goes wrong.
Gas Safe categories: Not all Gas Safe engineers can do all gas work. They're registered for specific categories:
- CCN1 – Domestic natural gas metres and regulators
- CENWAT – Central heating and hot water (this is the main one for boilers)
- CKR1 – Cookers
- HTR1 – Gas fires
Before hiring a heating engineer for gas work, verify their Gas Safe registration online at www.gassaferegister.co.uk and check they hold the right categories for your job.
Additional heating engineer qualifications:
- OFTEC registration (if working on oil boilers)
- Unvented Hot Water (G3)
- Various manufacturer-specific training (Worcester Bosch, Vaillant, etc.)
The Overlap: Plumbers Who Do Heating Work
Now here's where it gets interesting and, honestly, where most of the confusion comes from.
Many plumbers train in heating work and become Gas Safe registered. They're fully qualified to work as both plumbers and heating engineers. In fact, this is incredibly common – most experienced plumbers you'll find offer both plumbing and heating services.
The Multi-Skilled Professional
A plumber with Gas Safe registration can:
- Do all general plumbing work
- Work on gas boilers and central heating
- Install complete bathroom suites
- Service your boiler annually
- Fix that dripping tap
- Clear your blocked drain
This is actually the ideal scenario for most homeowners. Having one trusted professional who can handle both your plumbing and heating needs is brilliant. You build a relationship with them, they understand your property's systems, and you're not constantly ringing different people for different problems.
How to Tell What Someone Can Do
When you're searching for "plumbers near me" or looking at profiles on platforms like Trader Street, here's what to check:
General plumbers:
- List plumbing qualifications (Level 2/3 Diplomas, NVQs)
- Advertise bathroom installations, tap repairs, drainage work
- Don't mention boilers or gas work
Heating engineers:
- Prominently display Gas Safe registration number
- List boiler servicing, central heating, gas work
- May or may not offer general plumbing
Plumber-heating engineers (the multi-skilled ones):
- Have both plumbing qualifications AND Gas Safe registration
- Advertise full range: bathrooms, heating, boilers, general plumbing
- Often describe themselves as "Plumbing and Heating Engineers"
Most established local plumbers fall into this third category. It makes business sense for them and convenience sense for you.
When You Need a Plumber (Not a Heating Engineer)
Right, let's make this practical. Here are scenarios where you specifically need a plumber.
Bathroom and Kitchen Issues
Call a plumber when:
- You're installing or renovating a bathroom
- Kitchen sink is blocked or leaking
- Toilet won't flush properly or is leaking
- Shower head is broken or pressure is poor
- Taps are dripping or need replacing
- You want to add a downstairs toilet
- Installing a new washing machine or dishwasher
- Water pressure throughout the house is low
These are all water system issues that don't involve gas or central heating, so a general plumber is perfect.
Drainage Problems
Call a plumber when:
- Drains are blocked or slow-draining
- Waste pipes are leaking
- You've got bad smells from drains
- External drains are backing up
- Gutters need connecting to drainage
Some plumbers specialise in drainage work. For serious drainage issues, you might need a drainage specialist, but start with a general plumber who can assess whether specialist help is needed.
Emergency Water Issues
Call a plumber (or emergency plumber UK) immediately when:
- Pipe has burst and is flooding your property
- Major leak you can't stop
- Complete loss of water supply (though check neighbours first – might be supplier issue)
- Severe toilet leak causing water damage
For these emergencies, search "24 hour plumber near me" to find someone who can attend urgently. Many plumbers offer emergency call-outs, though they charge premium rates (typically £120-£220 for the call-out alone).
General Water System Work
Call a plumber when:
- Replacing old pipework
- Installing outside taps
- Fitting water softeners
- Installing water filters
- Upgrading stop taps
- Moving water pipes for building work
Basically, if it involves water (but not heating water via gas), you need a plumber.
When You Need a Heating Engineer (Not Just a Plumber)
Now let's flip it around. Here are situations where you specifically need someone who's Gas Safe registered and qualified in heating work.
Boiler-Related Issues
Call a Gas Safe heating engineer when:
- Boiler won't fire up or keeps cutting out
- No hot water from your boiler
- Radiators aren't heating up properly
- Boiler is making strange noises (kettling, banging, whooshing)
- Boiler showing an error code
- Boiler is leaking water
- You need your annual boiler service
- You're getting a new boiler installed
Even if your regular plumber is brilliant, if they're not Gas Safe registered for boiler work, they legally cannot touch your boiler. Don't let them. It's not worth the risk.
Central Heating Problems
Call a heating engineer when:
- Some radiators are hot, others are cold
- Heating system has air in it and needs bleeding
- Heating works but temperature control isn't right
- Thermostat seems faulty
- Heating pump has failed
- System needs power flushing (rust and sludge removal)
- You're adding radiators or underfloor heating
Gas Appliance Work
Call a Gas Safe engineer when:
- Installing or moving a gas cooker
- Installing or servicing a gas fire
- Any gas detection issues
- You smell gas (actually, call the National Gas Emergency Service first on 0800 111 999, then a Gas Safe engineer)
Landlord Requirements
If you're a landlord, you legally need a Gas Safe engineer for:
- Annual gas safety inspections (legal requirement)
- Gas safety certificates (CP12)
- Any gas appliance servicing or repairs
Using someone who's not Gas Safe registered will result in invalid certificates and potential prosecution.
The Cost Difference
Let's talk money, because this often influences who people call.