Project Overview
Plumb London replaced an ageing boiler at a veterinary practice in Peckham, SE15 — a commercial client we have looked after since 2015. We installed the practice’s original Ideal Logic boiler that year and have serviced it regularly since. In June 2026, the boiler developed a fault; on attendance we restored it to operation, but a closer inspection showed an ageing appliance reaching the end of its reliable life, alongside flue and condensate arrangements no longer meeting current standards.
We gave an honest recommendation to replace rather than keep patching, and carried out a full replacement with a new Vaillant ecoTEC Plus 424 boiler — completed in a single day, scheduled around the practice’s opening hours so it could stay open.

The Client’s Brief
A working veterinary practice cannot simply close for building works, so the client needed a reliable, compliant heating system restored with the absolute minimum of disruption to a busy, occupied premises. As a long-standing client, they also wanted what they had always had from us: a straight assessment of whether the existing boiler was worth keeping and works carried out properly and to current standards rather than a short-term fix.
Our Survey & Recommendations
The boiler had shut down on a fault. On attendance, our engineer traced it to a blocked condensate trap, cleared it, reset the boiler and restored operation. With the system running again, a fuller inspection revealed the deeper picture:
- The boiler was kettling — a knocking, boiling-kettle noise that indicates sludge and scale build-up restricting flow, typical of an ageing system.
- The external condensate pipework did not meet current standards.
- The flue was not sealed internally as current requirements demand.
- The hot water zone valve head had failed.
Given the boiler’s age — installed in 2015 — combined with the kettling and the several arrangements no longer meeting current standards, we advised that continued repair was poor value and recommended a full replacement, which we quoted. This was the honest call: we could have left the boiler limping along, but the long-term answer for the practice was a new, efficient, compliant system.
Planning & Preparation
With the recommendation accepted, the priority was scheduling. A veterinary practice needs its premises open, so we planned the full replacement as a single-day job on Friday 12 June 2026 — ahead of the weekend, so any settling-in happened while the practice was closed and the working week was undisturbed.
The Work We Carried Out
- Isolated services and drained down the heating system as required
- Decommissioned and removed the existing boiler, flue and associated components
- Carried out an Adey MagnaCleanse system flush in accordance with BS 7593
- Supplied and installed a new Vaillant ecoTEC Plus 424 heat-only boiler, with a 10-year manufacturer’s warranty
- Supplied and installed a new horizontal flue system with terminal guard and all accessories to current regulations
- Altered and modified existing pipework to accommodate and connect the new boiler
- Completed all plumbing and electrical connections
- Upgraded the external condensate discharge to 32mm, routed to a suitable waste point and insulated throughout
- Installed a new Vaillant 22mm boiler protection filter on the return
- Supplied and fitted new 22mm two-port motorised zone valves on both the hot water and central heating circuits
- Refilled and recommissioned the system and treated it with inhibitor
- Wired and tested the installation to current Part P and Part L requirements
- Supplied and fitted a new Honeywell T3R wireless programmable thermostat
- Connected the new boiler to the existing heating and hot water controls
- Supplied and fitted a new carbon monoxide alarm
- Tested the existing gas installation for tightness
- Checked radiator performance and balanced the system where necessary
- Demonstrated the new system and controls to the client
- Fully commissioned the installation, completed Benchmark documentation, notified Building Control and registered the works with Gas Safe
- Removed all waste and left the work area clean and tidy
A formal testimonial was not obtained for this project. The client has, however, trusted Plumb London with the care of their heating system since 2015 — a continuing relationship that speaks for itself.
Timeline & Completion
The installation was carried out by our engineers, Andrew and Charlie, in a single day on Friday 12 June 2026. Scheduling it for the Friday meant the practice stayed open and operational throughout the working week, with the changeover completed before the weekend.
Challenges & How We Solved Them
Honest diagnosis over a quick fix. The simplest response to the fault would have been to clear the condensate trap, take the call-out fee and leave. We did clear it and got the boiler running — but the kettling, the non-compliant flue and condensate, and the failed zone valve told the real story of an appliance near the end of its life. We gave the client the honest recommendation to replace, with the reasoning, rather than charge for repeated repairs on an ageing boiler.
Keeping a working practice open. A veterinary practice can’t close for a heating replacement. We resourced the job as a single-day installation and scheduled it for the Friday before the weekend, so the premises remained operational through the week and any disruption fell outside working hours.
Bringing the installation up to current standards. This was not simply a like-for-like swap. The existing flue and condensate arrangements no longer met current requirements, so we installed a new, correctly sealed flue and upgraded the condensate discharge to 32mm, fully insulated — leaving a system that is compliant, not merely newer.
Protecting the new boiler. Connecting a new boiler to an established system risks circulating old sludge and scale. A full MagnaCleanse flush to BS 7593, a new protection filter and inhibitor treatment safeguard the new appliance and its warranty. As the boiler was integrated with the practice’s existing pipework, radiators and controls, we advised the client to monitor the wider system and report anything untoward.
The Finished Result
The practice now runs on a new Vaillant ecoTEC Plus 424 boiler, backed by a ten-year manufacturer’s warranty — available because Plumb London is a Vaillant Advance accredited installer. The noisy, ageing boiler is gone, replaced by an efficient, quiet system with a new compliant flue, upgraded condensate, new zone valves on both circuits, a protection filter and a programmable wireless thermostat for straightforward control. The installation was commissioned, Benchmark-certified, registered with Gas Safe and notified to Building Control. A client we have served for over a decade has dependable, compliant heating once again — installed in a day, without closing their doors.
Project Investment
As a client we have looked after since 2015, the practice was charged on a loyalty basis — the same rate as the original installation we completed for them over a decade earlier. Holding that price over more than ten years reflects the value we place on a long-standing relationship; for the practice, it delivered a complete, compliant and fully warranted new heating system, installed in a single day without closing their doors.
Why Choose Plumb London
- Honest, transparent advice. We identify and communicate the full scope of any works, including issues discovered beyond the original brief.
- A phased approach to complex works. You are never committed beyond what has been fully diagnosed and agreed.
- Clear quotations and written reports. You always understand exactly what you are paying for, and why.
- Engineer continuity. Wherever possible we keep the same engineer on your building, so site knowledge is retained across visits.
- Coordinated, considerate scheduling. We work around your operations to minimise disruption to your business and team.
- Compliance and documentation. Works are carried out to current regulations, with the records businesses and managing agents need for tenants, insurers and audits.
- A family-run business, built on repeat custom, referrals and genuine customer care — this client has been with us since 2015.
Frequently Asked Questions
When should a boiler be replaced rather than repaired? Once a boiler is around ten years old and showing signs such as recurring faults, kettling or falling efficiency, repairs become harder to justify. The sensible approach is to weigh the likely ongoing repair cost and downtime against a replacement — which is exactly the assessment we gave this client before recommending a new boiler.
What causes a boiler to “kettle” or make banging noises? Kettling is usually caused by sludge and limescale building up on the heat exchanger, restricting flow and causing the water to overheat and boil noisily. A system flush can help, but on an ageing boiler a replacement, properly flushed and protected, is often the better long-term answer.
Can a boiler be replaced without closing my business for long? In most cases, yes. A like-for-like heat-only boiler replacement is typically a single-day job, and we schedule it around your opening hours — here we completed the work on a Friday so the practice stayed open all week.
Do you service boilers after installation? Yes. Annual servicing maintains efficiency, safety and warranty validity. For commercial premises, ongoing servicing can be formalised within a planned preventative maintenance (PPM) contract — the kind of long-term arrangement we have provided this client since 2015.






