Gurney Slade's Local Boiler Installation Specialist

Commissioning checklist and the Benchmark record

Every new boiler installation comes with a Benchmark commissioning checklist that has to be completed and signed at the point of installation — recording gas or oil pressure readings, flue gas analysis results, system flush confirmation and control settings. It's not paperwork for its own sake: manufacturers require a fully completed Benchmark record as a condition of the boiler's guarantee, and an incomplete or missing record is one of the most common reasons a warranty claim gets refused later. We complete and hand over the Benchmark log, along with the Gas Safe or OFTEC notification, on the day of installation rather than promising to send it on, specifically so the paperwork exists from day one if it's ever needed.

What a proper heating quote should include

A quote worth relying on states the specific boiler or equipment model, the labour and materials it covers, whether a system flush and magnetic filter are included, what happens to old equipment removal and disposal, and what's excluded — an unexpected gas pipe upsizing or asbestos-containing material discovered during removal, for example, which can't always be known before work starts. It should also state who's completing the Gas Safe or OFTEC notification and Benchmark commissioning record, since that's the paperwork that protects both the manufacturer's guarantee and the property's compliance history when it's sold. A vague one-line quote makes comparing genuinely different offers difficult, because two prices that look similar can cover very different scopes of actual work.

• Specific make and model, not just "combi boiler"
• Flush and magnetic filter stated as included or excluded
• Old equipment removal and disposal covered
• Notification and Benchmark record responsibility stated

Chasing pipework into lime plaster and stone walls

Solid stone or cob walls finished in lime plaster, common in the older parts of Gurney Slade, behave very differently to modern plasterboard when a pipe run needs chasing in. Lime plaster is softer and more porous than gypsum, so cutting a neat, consistent chase without blowing the surface needs a slower hand and finer disc than a stud-wall job, and any repair has to be made good in a lime-based skim rather than modern filler, which can trap moisture behind it and cause the patch to fail. On solid stone we sometimes surface-mount pipework in painted conduit instead of chasing, particularly where the wall is a significant structural thickness and chasing would weaken it. Knowing which approach a wall needs before starting avoids expensive plaster damage.

Weather compensation: matching flow temperature to outdoor conditions

Weather compensation uses an external sensor to adjust the boiler's flow temperature automatically as outdoor temperature changes, running a lower flow temperature on a mild day and a higher one on a cold one, rather than the fixed flow temperature most boilers are left on permanently. Because condensing boiler efficiency is highest at lower flow and return temperatures, weather compensation keeps the system closer to peak efficiency across the heating season instead of only on the coldest days it was set up for. It needs a compensation curve set to suit the specific building's heat loss characteristics — the same curve on a well-insulated modern semi and a solid-wall Victorian terrace won't give the same comfort result. We set the curve empirically over the first heating season rather than leaving factory defaults in place.

Signs a boiler repair is no longer the right call

A boiler that's failing repeatedly, needing a different part replaced every service, or over roughly ten to fifteen years old is approaching the point where continued repair costs more over time than replacement, particularly once a heat exchanger — the most expensive single part — starts to show signs of failure through leaks or reduced output. Efficiency is the other half of the calculation: an older non-condensing boiler running at 70-80% efficiency against a modern condensing combi at over 90% means a meaningful chunk of every unit of fuel burned in the old boiler is simply lost up the flue. We give a straight answer on repair versus replace based on the fault found and the boiler's age and condition, rather than defaulting to whichever is more profitable to us on the day.

Pumped-oil versus gravity feed: does it matter?

Older oil systems sometimes still rely on gravity feed, where the tank sits higher than the burner and oil flows down to it under its own weight; a pumped system uses the burner's internal pump to draw oil up from a tank at any level, including below the boiler. Gravity feed limits where a tank can be sited and is more prone to airlocks if the line runs dry, while a pumped system is more flexible on tank position but needs the pipe run and lift height kept within the burner pump's rated capacity — usually no more than a few metres of lift and a set maximum run length. When we replace an oil boiler we check which type the existing tank and pipework support before assuming a straight swap, because a tank sited for gravity feed may need repositioning or a different pump to suit a modern burner.

Low-loss headers on larger or multi-zone systems

On a system with several heating zones or a boiler oversized relative to any single zone's flow requirement, a low-loss header hydraulically separates the boiler's primary circuit from the secondary zone circuits, so each side can run its own pump and flow rate without one interfering with the other. Without it, a zone valve closing on a multi-zone system can starve the boiler of flow or force excessive pump pressure through the remaining open zones. It's most relevant on larger properties or ones with commercial premises attached, where several distinct heating circuits — perhaps a shop unit and a flat above — share one heat source. Getting the header sized to the boiler's actual flow rate, not just fitted as standard, is what makes it work rather than just adding another connection.

Combi, system or regular: which suits the property?

A combi boiler heats water directly from the mains on demand with no cylinder or tank, which suits smaller households with modest simultaneous hot water demand and properties with no loft or airing cupboard space to spare. A system boiler heats a stored cylinder, giving stronger and more consistent flow to multiple outlets at once — better suited to larger households or properties with more than one bathroom — while a regular (open-vent) boiler additionally needs a cold feed and expansion tank, usually only chosen now where an existing system layout makes it the simpler swap. On stock like cottages and modern estates the right answer depends on bathroom count and existing pipework layout as much as household size, which is why we ask about actual usage patterns rather than defaulting to whatever's currently fitted.