Central heating system check and survey across London

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.

How we deliver

No surprises, no upselling. The exact path every job follows.

1. 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. 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. 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. 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. 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. 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. 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.