A central heating system survey is the diagnostic before the work, a whole-system health check that tells you whether you need a flush, a filter, a boiler swap, or just a balance and an inhibitor top-up.
A heating system survey is different from a one-off repair visit. A repair visit fixes the symptom in front of us (a cold radiator, a dripping pump, a boiler lockout) and stops there. A survey tests the whole loop end to end, so the spec for the next bit of work, a power flush, an inhibitor refresh, a magnetic filter install, or a full system replacement, is driven by data. We are normally called in for pre-purchase due diligence where the heating age is unknown, pre-refurb scoping where new radiator runs or underfloor loops will be added, and post-incident review after a sludge contamination, a cylinder failure, or unexplained pressure loss. The output is a written report you can hand to a contractor, a buyer, or an insurer.
On the day we run a sealed-system pressure test held over 30 minutes, a per-radiator balance check with infrared thermometers on every flow and return tail to confirm the 11 K design differential, flow and return temperatures at the boiler, a pump head reading against the manufacturer curve, an expansion-vessel pre-charge check (1.0 bar at zero system pressure), and a system-water sample for Sentinel X100 strength and a TF1 sludge-load visual grade. Where a replacement is on the table we measure heat-loss room by room to BS EN 12831 so the boiler and radiator sizing is right. The report references BS 7593 inhibitor and flushing guidance and comes with a tiered options sheet, flush only, flush and magnetic filter, new boiler and cylinder, each with indicative pricing so you can stage the work.
Where this service applies
- Pre-purchase due diligence on a property with undocumented heating history
- Pre-refurb scoping where a bathroom or kitchen rework will touch existing heating loops
- Unexplained pressure loss on a sealed system with no visible leaks
- Recurring cold spots, kettling, or filter packing up between services (sludge assessment)
- Second opinion on a quoted boiler swap to confirm sizing and replacement case
- Loft conversion or extension needing heat-loss recalc to BS EN 12831
- Insurance survey after a heating-side leak or contamination event
- Building Regulations Part L compliance check before signing off a refurb
How we deliver
No surprises, no upselling. The exact path every job follows.
- 1
System walk-round and inventory
Boiler make, model, age, and benchmark log, cylinder type and capacity, every radiator counted, pump model, controls layout, and pipework runs identified to flow and return. - 2
Sealed-system pressure test
System charged to 1.5 bar and held for 30 minutes, pressure drop recorded. Any drop signals a leak somewhere on the loop and triggers a leak-detection follow-up. - 3
Per-radiator balance check
Infrared thermometer on every flow and return tail to confirm the design 11 K differential, surface temperatures recorded for cold-spot mapping. - 4
Boiler-side measurements
Flow and return temperatures, pump head against the manufacturer curve, expansion-vessel pre-charge at zero pressure (target 1.0 bar), gas inlet pressure at the test point. - 5
System-water sample
Sample drawn from the magnetic filter or a drain-off, Sentinel inhibitor test kit reads X100 or F1 concentration, TF1 sample bottle visual-graded against the sludge scale. - 6
Heat-loss recalculation
Where a replacement is on the table, room-by-room heat-loss to BS EN 12831 to size the boiler and the radiators against the actual building fabric, not the legacy install. - 7
Written report and tiered options
PDF inside three working days with photographs, all measurements, BS 7593 references, and a tiered options sheet (flush only, flush and filter, new boiler and cylinder) with indicative pricing per option.