Testo 300+ Flue Gas Analyser Ultra Smart Kit – 0564 3004 02 Wireless Probes + Combustible Gas Leak Detector BS7967 Summer Promotion - until end of August 2026 - get a FREE set of Water Pump Pliers when you purchase a Testo Flue Gas Analyser The Testo 300+ Ultra Smart Kit is the most complete configuration in the range, taking the Smart Kit's wireless flow/return temperature and gas pressure measurement capability and adding a combustible gas leak detector to the same case. A single kit covers flue gas analysis, wireless temperature and pressure measurement, and gas leak checking — the full set of checks likely to be needed on a domestic boiler service or commissioning visit, without carrying a separat