Why the Cheapest Quote Is Usually the Most Expensive

Why is the cheapest quote usually the most expensive?

Because the three quotes in front of you are almost never for the same job. Two firms have priced a cylinder swap including the discharge pipework, a new isolator, the old unit taken away and the floor put back. The third has priced the cylinder and the hours to hang it. That firm is not more efficient, it has written a shorter job, and the difference gets found on site with the water off and the old unit already on the landing.

Every trade job has a cost floor made of real things: engineer time, parts at merchant prices, the van, fuel, parking, waste, insurance. Those costs do not move because a customer wanted a lower figure. When a quoted price drops below that floor, one of three things is happening. The scope has been cut and the exclusions are in the small print or nowhere. The price is a guess made without looking properly and will be revised. Or the work will be done to a standard that brings you back into the same cupboard in two years.

The uncomfortable version: a firm winning work on price alone has to make the margin back somewhere, and the two easiest places are the parts and the second visit. Neither is visible on the day you compare figures at a kitchen table.

A quote you cannot account for line by line is not cheap. It is unfinished. Price the gaps yourself before you decide anything.

What actually gets cut to reach the lowest number

Four things get cut, in roughly this order: the survey, the named parts, the ancillaries and the making good. Each lowers the number on the page without lowering the real cost of finishing the job, so each reappears later as an extra or as work nobody ever completed.

The survey goes first because it is the cheapest thing to skip and the most expensive thing to have skipped. A price given over the phone for work nobody has looked at cannot account for the cupboard the cylinder will not come out of, the buried pipework in a Victorian conversion, the liquid screed in a new build that has to be cut rather than lifted, or an existing electrical supply to the immersion that is not fit to reuse. In London housing those are not rare surprises, they are the normal condition of the job.

Then the parts stop being named. A quote that says cylinder, boiler or valves as required has reserved the right to fit whatever is cheapest on the day. That matters less while the appliance is new and a great deal when it fails. A unit from a manufacturer with real distribution here can often be repaired the same week because the common failure items sit on a merchant shelf in London. Something picked purely on price can leave you waiting on a component from abroad, and you feel that decision all at once, in February, with no hot water.

The ancillaries go next. Isolation valves, the discharge pipe run, insulation, the electrical isolator, the fittings to adapt old pipework to new connections, the old unit taken away. On a cylinder or boiler replacement those are a real share of the materials. A quote listing only the headline appliance has either absorbed them silently or intends to add them, and the second is more likely when the figure is already the lowest of the three.

A deposit request attached to a very low number is worth pausing over, and should you ever pay a plumber upfront is a question with a narrower honest answer than the trade generally admits.

• No site visit, or a visit that did not include opening the cupboard and looking at the existing pipework and electrics
• Parts described by category rather than by manufacturer and model
• No mention of the discharge pipework, the isolator, or the electrical connection
• Nothing about who lifts the floor, who puts it back, and to what standard
• Nothing about waste removal or the old appliance
• No statement of what happens to the price if the work turns out larger than it looked

The parts line is where the money quietly leaves

Ask for every major item by manufacturer, model and capacity or output, and refuse the word equivalent. Equivalent is the most expensive word on a plumbing quote, because it means the specification is whatever the firm decides once the deposit has cleared. Two cylinders of the same litre capacity can differ in coil surface area, in insulation thickness, and in whether the safety components are standard fittings any engineer can source or proprietary parts sold from one place.

Coil surface area is the one nobody thinks about and everybody feels. It decides how fast the boiler can put heat into the stored water. A cheaper cylinder with a smaller coil reheats more slowly for the rest of its life, in a city where hard water furs that coil from the first winter. You never see it on an invoice. You see it every morning in the reheat time, and eventually as a call out for a cylinder that is not really faulty, only underspecified and now scaled.

The same applies to boilers and to the thermal stores fitted in purpose built blocks. Judge them on failure modes and on what is serviceable, not on the brochure. Ask whether the common failure items are stocked here, and whether a diverter valve or a pump can be changed as a part or only as a sealed assembly. A unit that scores badly on those is cheap to buy and expensive to own, and the firm quoting it will not be the one attending in year five.

On an unvented cylinder repair the parts line is the whole argument, because a pattern expansion vessel and the manufacturer component are not interchangeable in the way a low quote quietly implies.

• Manufacturer, model and capacity or output written on the quote, not promised verbally
• Whether the common failure parts are stocked in the UK and by whom
• Whether major components can be replaced individually or only as an assembly
• Who registers the appliance with the manufacturer, and when
• Whether the quote covers the old unit being removed and taken away

What the second visit actually costs

A second visit costs far more than the hours it adds, because almost none of the cost of attending is the time spent working. It is the travel across London, the parking or the suspended bay, the loading in and out, the diary slot that cannot be sold to anybody else, and a whole day gone at your end too. That is why a job done once at a fair price beats the same job done twice at a keen one.

The second visit arrives by a few predictable routes. A part was not named, so the wrong one was ordered. Nobody surveyed, so the isolation valve that should have been changed while the system was drained was not on the list, and draining twice is two days of disruption for one repair. The making good was excluded, so the floor is open and a second trade has to be found. Or the diagnosis was never really done, and the fault is still there after the guess has been fitted.

That last route is the expensive one, and it is specific. Where hot water is the problem, the failure could be the immersion element, the cylinder thermostat, the wiring centre, a motorised valve, the boiler itself or the control telling the boiler what to do. Fitting a part without proving which one it is means paying for parts until one of them works. A firm that charges to diagnose properly and tells you what it found looks dearer on the quote and is almost always cheaper on the invoice, because it fits one component rather than three.

So add it up before you decide. If the cheapest quote sits a few hours of labour below the others and carries one realistic risk of a return trip, a second drain down or a component fitted on a guess, the saving is already spent.

Ask directly whether a return visit to fit an ordered part is charged again, and get the answer in writing. It is a short question that settles most of the argument before it happens.

Access, making good and waste: the exclusions that reset the price

Making good is putting the building back after the plumbing is finished, and it is the line most often missing from the cheapest quote and most often argued about on the last day. The quote should say who lifts the floor, who re lays it, what standard the surface is left at, who patches plaster and who removes the waste. A firm that leaves all of that off has priced a plumbing job inside a building nobody has to repair.

London housing makes this specific rather than theoretical. In Victorian conversions the pipework is often buried in walls or chased into floors, so reaching a joint means opening plaster and sometimes lifting boarding in the flat below. In purpose built blocks the cylinder or thermal store sits in a tight riser cupboard and will not come out until a section of frame or a door lining comes off, often with the building manager notified about the communal route. In new builds the heating pipework sits in liquid screed, and screed does not lift like floorboards, it has to be cut.

Waste is its own line. An old cylinder, a boiler, packaging and pipework do not fit in a domestic bin, so somebody is paying to remove them, and a quote that does not mention it has decided that somebody is you. Parking is the same: a permit or a suspended bay is a real cost on a London job and belongs on the page, not on the final invoice.

Leak detection and repair is where this bites hardest, because a figure that covers the tracing but not the making good is not a quote for the job you actually have.

• Who opens the floor, wall or ceiling, and who closes it again
• The standard the surface is returned to: made good to plaster is not made good and decorated
• Who removes the old appliance, the packaging and the waste pipework
• Whether a permit or suspended bay is needed and who pays for it
• Whether building management or a freeholder has to be notified for communal access

How to compare three quotes so the comparison means something

Normalise them before you look at the totals. Write the scope you actually want on one sheet, then price each quote against it by adding the cost of whatever it leaves out. The three numbers are now for the same job, and the ranking usually changes. It takes twenty minutes and it is the most useful thing a householder can do with a plumbing decision.

Then look at how each firm behaved, not only at what it wrote. Did they look at the actual installation or price it from a phone call? Did they ask what the symptom was, when it started and what had already been changed? Did they name the parts without being pushed? Did they tell you something you did not want to hear, such as the work being larger than you hoped? Willingness to describe a job accurately when the accurate description loses the sale is the most reliable signal there is.

Be careful with the outlier in either direction. One quote far below the other two usually means that firm understood the job differently, not that the other two are profiteering. One far above deserves the reverse question: what have they seen that the others have not. Sometimes the answer is that the pipework or the electrical supply needs work the others ignored.

Check first whether each quote has absorbed the plumber call out fee or left it outside the total. Two otherwise identical figures are not comparable when one of them still has an attendance charge to come.

Comparing like for like is also most of how to tell if a plumber is overcharging you, because a single quote read on its own gives you nothing to measure it against.

• Write the scope you want once, then price every quote against it
• Add the cost of each missing item to the quote that omits it before comparing totals
• Ask each firm what the quote excludes, as an open question
• Ask what happens to the price if the job turns out larger, and how that gets approved
• Ask how they will prove the diagnosis before fitting anything

Is the cheapest quote ever the right one?

Yes, and it is worth saying plainly. The cheapest quote is the right one when it is the cheapest quote for the same defined work, and that happens more often than the cynical version of this article suggests. A smaller firm with lower overheads, an engineer who lives locally and will not spend two hours crossing London, or a firm with a gap in the diary next Tuesday can all be genuinely cheaper while doing identical work to the same standard.

The test is not the number, it is whether the number is accounted for. If the scope matches, the parts are named, the labour basis is stated, the exclusions are written down and somebody has actually looked at the job, then a lower price is simply a lower price and you should take it.

What should worry you is a low figure with nothing behind it: one produced without a visit, one that arrives with pressure to decide today, or one where a specific question gets a reassurance rather than an answer. A price is a claim about work, and a claim that cannot be examined is not a bargain.

Why advertised results are not a shortcut to a fair price

Paid placement tells you about a marketing budget, not about workmanship. That is not an accusation against anybody who advertises, and plenty of good firms do. It is arithmetic: a business paying for each click, each lead or each listing position has to recover that cost, and it comes out of the job, the parts or the margin somewhere. Where leads are bought through a middleman, a share of what you pay leaves before the engineer is paid, which puts pressure on exactly the lines this article is about.

So the order you are shown is not a ranking of quality, and treating it as one is how people accept a quote they never examined. Use it as a list of firms to contact, then apply the same test to all of them: named parts, written scope, stated exclusions, a real look at the job.

A no call out fee plumber at the top of the results is advertising a removed line rather than a lower total, and the two are easy to confuse when you are comparing in a hurry.