How to choose a plumber or heating engineer you can trust

Most people pick a plumber in one of two moods: calm, with a few weeks to compare options, or standing in a puddle at eleven at night with a towel in each hand. The checks that protect you are the same either way. This guide takes them in the order they come up, from the first phone call to the review you leave afterwards, and applies to heating engineers too, with one firm rule added for gas.

One thing to be clear about first: Üsküdar Tesisat is a publication, not a trade directory. We don't recommend, rank or book tradespeople, and nobody pays to appear on these pages. What follows is a way to judge them yourself, wherever you live.

Start by deciding what kind of job it is

Emergency: control the water first

A burst pipe, a tank overflowing through the ceiling or water running near sockets is an emergency. So is any smell of gas, which belongs to your local gas emergency line and not to a plumber's mobile. In a water emergency your first move is the stopcock, not the phone. Once the flow has stopped, the job usually drops from "emergency" to "urgent", and that changes how much choice you have. A plumber who can come at eight the next morning instead of midnight will often charge less and have more time to do it properly.

If you do need someone tonight, still ask for the call-out charge and hourly rate before they set off, ask when out-of-hours rates begin, and get the name of the business rather than just a first name.

Planned work: use the time you have

Replacing a cylinder, moving a radiator, refitting a bathroom or tracing a slow drip under the floor are all planned jobs, even if the drip is driving you mad. Here you can collect two or three quotes, check registration properly and look at past work. For bigger projects, settle your own scope before anyone prices it; working through a bathroom renovation plumbing checklist makes quotes far easier to compare later.

Some jobs sit in between. A boiler that stops in January isn't flooding anything, but a home without heat or hot water, especially with a baby or an older relative in it, deserves same-day attention. Be honest about which category you're in, because it decides how much room you have to shop around.

What to tell them on the first call

Good tradespeople ask a lot of questions on the phone. A clear description means a better first visit, the right parts in the van and a more realistic idea of cost.

1. What you see, hear or smell. "Water dripping from the kitchen ceiling under the bathroom, worse when the shower runs" is far more useful than "a leak". Mention noises such as knocking, hissing or gurgling, and when they happen.
2. When it started and whether it's getting worse. A stain that has grown slowly over three weeks points to a different cause than one that appeared overnight.
3. What you've already tried. Turned off the stopcock, isolated the boiler, topped up the pressure, used a plunger. Say so, including anything that made it worse.
4. Where the stopcock is and whether it turns. If you don't know, say that too. A seized stopcock changes the job.
5. The equipment involved. The boiler's make and model from its data plate, the type of hot water system (combi, cylinder, instantaneous heater), the rough age of the property and the pipe material if you can see it.
6. Access. House or flat, which floor, parking, whether neighbours below need warning, whether a dog will be loose.

Take three or four photos before you ring: the problem itself, the wider area around it, any label or data plate on the appliance, and the stopcock. Many plumbers will look at pictures sent by message and can tell you straight away whether it's their kind of job.

If the problem is a hidden leak, such as a damp patch with no obvious source or a meter that ticks over with every tap closed, ask whether the business does leak detection or only repairs. They are different skills. Our water leak detection guides explain the warning signs, and knowing how electronic leak detection works helps you tell a methodical survey from someone who plans to lift floorboards until they get lucky.

Check registration, licences and insurance

Rules for plumbers vary widely between countries, and sometimes between states or regions inside one country. In some places all plumbing work needs a licence. In others, general plumbing is open to anyone, while particular kinds of work are controlled. Find out what applies where you live, from your local authority or the national body that oversees building work.

Gas is different. Any work on a gas appliance, gas pipe or flue, including fitting, servicing, moving or "just having a quick look at" a boiler, must be done by someone who holds the registration or licence your country requires for that work. Ask for their number and check it yourself on the official register, which normally also lists the appliance types each engineer is qualified for. A card in the van is not the same thing as a live entry on the register.

Similar controls often apply to unvented hot water cylinders and to electrical work on heating controls, so ask what certificates the job will produce.

Insurance is the other check. Ask whether the business carries public liability insurance, or the local equivalent, and whether they will show you the certificate. If a compression joint lets go a week later and floods the flat below, that policy is what pays for it. Trade association membership can be a good sign, but treat it as an extra rather than a substitute for registration and insurance.

Quotes, estimates and how charges are built

A quote is a fixed price for a defined piece of work. An estimate is an informed guess that can move once the job starts. Both are legitimate. Repair work, where nobody knows what's behind the bath panel until it comes off, is often estimated. A new installation should usually be quoted. What matters is that you know which one you have and that it's in writing.

Ask about each of these before you agree:

• Call-out or attendance charge. A fixed fee for turning up. Sometimes it includes the first chunk of labour, sometimes not.
• Hourly or daily rate. Ask whether time is charged in full hours, half hours or smaller blocks, and whether travel and trips to the merchant count.
• Minimum charge. Common, even for a five-minute fix.
• Out-of-hours premium. Evenings, weekends and public holidays usually cost more. Ask exactly when the higher rate starts.
• Parts and materials. At cost or with a mark-up, and whether you may supply your own. Many tradespeople won't guarantee parts they didn't buy.
• Waste removal. Taking away an old boiler, cylinder or bathroom suite may be extra.
• Tax. Check whether figures include VAT or sales tax.

When you compare quotes, line them up against the same scope. One may include making good the plaster while another leaves you with a hole in the wall. Send each business the same written list to price.

Warning signs worth walking away from

• Cash only, with a discount for "no paperwork". No receipt means no proof of the work and no guarantee.
• "You need to decide today", or a price that only holds if you sign on the spot.
• A large deposit for a small job, or any deposit without a written quote.
• Cold callers who "noticed a problem" with your pipes, roof or boiler while passing.
• No business name, nothing in writing and only a mobile number.
• A diagnosis they won't explain, or a refusal to show you the old part they replaced.
• A bill that grows mid-job without a conversation before the extra work begins.
• Anyone willing to touch gas without showing you a registration or licence you can check.

One of these on its own doesn't prove bad intent. Two or three together make a pattern you shouldn't ignore.

Questions to ask before you agree

• Have you done this exact type of job recently, and can I see photos or speak to a past customer?
• Who will actually do the work: you, an employee or a subcontractor?
• What does the price include, and what does it leave out?
• How long will it take, and what happens if you find something unexpected?
• Will the water or heating be off, and for how long?
• What guarantee do you give on your workmanship, and what warranty comes with the parts?
• Will you issue certificates or notify the authorities where that's required?
• How and when do you want to be paid?

Get the answers by email if you can; it settles most arguments before they start.

What the paperwork should look like

A proper invoice tells you exactly what was done. It should show the business's full name and contact details, the date, the property address, a description of the job, the parts used with quantities, the labour time or fixed fee, any tax and the total paid. For gas work and other controlled work there should also be a certificate or record of the kind your country requires.

The guarantee should be written too. Look for the length of cover, whether it covers workmanship, parts or both, and what you need to do to make a claim. Manufacturer warranties on boilers and cylinders often depend on the appliance being registered within a set period and serviced every year, so ask who is registering it.

Keep everything in one folder: quote, invoice, certificates and photos from before and after. If you ever sell, buyers and their surveyors will ask for it.

Leave a review that helps the next person

A useful review is specific. Say what the job was, how quickly they responded, whether the final bill matched the quote, how they communicated and whether they left the place tidy. Mention problems plainly and fairly. If something went wrong, give the business a chance to put it right before you post, and update the review if they do. "Fixed the leak under the kitchen sink in an hour, price as quoted, showed me the perished washer" is worth far more to a stranger than five stars and the word "great".

A few common questions

Should I always take the cheapest quote?

Not automatically. Check it covers the same scope as the others. A low price that leaves out making good, waste removal or a guarantee often ends up costing more.

Can a handyman deal with plumbing jobs?

For small things like a tap washer or a new toilet seat, often yes, depending on local rules. For gas, unvented cylinders or anything that needs a certificate, no.

Is it normal to pay a deposit?

For special-order parts or a large project, a reasonable deposit is common. It should be tied to a written quote, and you should get a receipt for it.