Guide
Questions to ask a plumber before you hire
Six questions that separate a plumber who has thought about your job from one who has quoted for a job like it. None of them are difficult, and all of them are answerable on the phone.
Are you Gas Safe registered, and for what?
Ask it even when the job is not gas, because the answer tells you what else they can help with. Where it is gas, ask for the registration number and check it on the public register, and confirm the categories cover the appliance. Boilers, cookers and fires are separate categories, and commercial appliances are separate again.
For an unvented cylinder, ask about G3 specifically, which is a different qualification from Gas Safe registration.
Is the price fixed or hourly, and what is not included?
Both are legitimate. What matters is knowing which you have agreed to and what sits outside it. The exclusions that most often become extras are making good after chasing walls, replacing valves found seized on the day, disposal of an old appliance, and any second trade the job turns out to need.
On an emergency call, ask whether the first hour is a call-out fee with time on top or a minimum charge including labour.
What happens if you find something unexpected?
Older properties routinely hide a surprise behind a panel. The question is not whether that will happen but what the plumber does when it does: stop and phone you, or carry on and add it to the bill. There is a right answer, and it is the first one.
Ask for a figure above which they will call before proceeding. Fifty or a hundred pounds is a normal threshold and it prevents most disputes.
Who else will the job need?
Bathrooms need a tiler, a plasterer and an electrician. Electric showers need an electrician. Kitchens need a fitter. Ask who is arranging and sequencing them, because a job with four trades and no one co-ordinating them is a job that takes twice as long.
If the plumber is subcontracting, ask who you pay and who is responsible if something is wrong.
What paperwork will I get?
For gas work, a Gas Safe building regulations notification and a commissioning record. For an unvented cylinder, a G3 certificate and a building control notification. For a boiler, the manufacturer's warranty registration. For a landlord safety check, the record itself within 28 days.
Ask when each arrives. Paperwork that never turns up is the commonest complaint about otherwise good work, and it is the thing a future buyer's solicitor asks for.
Common questions
Should I pay a deposit?
For a job with materials to buy, a deposit covering the materials is reasonable. A deposit approaching half the total before any work starts is not.
What if I am not happy with the work?
Raise it immediately and in writing. Most plumbers will return and put it right. For gas work done badly, Gas Safe Register will inspect the installation at no charge.
Do I need three quotes?
Two or three for anything over about a thousand pounds. For a tap change, one. Comparing quotes only works when they cover the same scope, so send the same written description to each.