Are Customer-Supplied Plumbing Parts Covered by Warranty?
It is fairly common for homeowners to ask whether they can supply their own taps, valves, or replacement parts for a plumber to fit, often to save money or because they have a specific product in mind. While we are generally happy to fit customer-supplied items, it is important to understand how this affects warranty cover before making that decision.
This guide explains our policy clearly so you can make an informed choice about sourcing materials yourself versus having us supply them as part of the job.
Our Warranty Policy on Customer-Supplied Materials
Customer-supplied materials are not covered by our workmanship or product warranty. This means that if a part you have sourced yourself turns out to be faulty, of poor quality, or simply unsuitable for the application, we are not able to offer the same warranty protection we would on parts we supply and fit ourselves.
This is a standard position across the trade, and it reflects the fact that we have no control over the quality, specification, or provenance of parts we did not select or purchase ourselves.
Why This Distinction Exists
When we supply materials as part of a job, we choose products we know are reliable, correctly specified for the application, and appropriate for the pressures and conditions of your system. This gives us confidence to stand behind the work with a warranty covering both our workmanship and the part itself.
With customer-supplied items, we can only warrant our own fitting and installation work, not the performance or longevity of the part itself, since we did not select, inspect, or guarantee its quality before it arrived on site.
Compatibility and Fit Risks
Beyond warranty considerations, customer-supplied parts occasionally turn out to be the wrong size, an incompatible connection type, or a lower specification than the existing system requires. This can result in additional time being needed on site to source a suitable replacement, which affects the overall cost and duration of the job.
The Cost Comparison
When we supply materials, they are charged with a 20% mark-up on the trade cost, which reflects sourcing, guaranteeing suitability, and warranty cover. Some customers still prefer to source premium or specific-brand fittings themselves, and this remains entirely your choice, provided you are comfortable with the warranty implications explained above.
Making the Right Choice for Your Job
For straightforward repairs using standard parts, letting us supply materials is usually the simplest option and ensures full warranty cover. For specific design choices, such as a particular tap or radiator style for a renovation, supplying it yourself can make sense, provided you check compatibility and specification carefully, or ask our engineer to confirm before you purchase.
Need a plumber or heating engineer?
We arrange appointments across Wimbledon and south west London at clear hourly rates. Call 020 3727 2578 or request an appointment.