HVAC worker cheat sheets built for repeat field use in United Kingdom
Built for United Kingdom field work where boilers, hydronic controls, ventilation, and air-source heat pumps sit beside lighter-duty ducted systems. These are original quick-reference sheets for techs and installers. Use them for faster diagnosis, safer handoffs, and cleaner callbacks. Always follow manufacturer data, lockout/tagout procedure, and local code when the cheat sheet and the equipment disagree.
- Expect Pa and L/s to appear more often than in. w.c. and CFM on airflow and fan checks.
- Temperatures are generally discussed in C, so split and rise expectations need to be translated mentally if a manual uses US data.
- Gas and combustion calls demand tighter commissioning and documentation discipline than quick rule-of-thumb service.
- Boiler lockouts, circulation faults, controls integration, and low-system-pressure complaints.
- Heat pump commissioning, weather compensation adjustments, and defrost behavior on newer installs.
- Ventilation and condensate details where compact properties leave little tolerance for sloppy routing.
- Gas appliance work must follow the competency and legal requirements that apply locally before any fault-finding becomes a sales pitch.
- Electrical isolation, F-Gas obligations, and manufacturer commissioning records matter more than generic field shortcuts.
- When you change settings, document them clearly so the next visit understands what was altered and why.
- When translating US-style HVAC rules into UK unit conventions and equipment types.
- For boiler or heat-pump callbacks where sequence, flow, and controls all need clear notes.
- To standardize handover notes on compact residential systems with layered controls.
Airflow references your crew can use on the next call
Airflow, CFM, and Static Pressure Quick Check
Use this when you have hot and cold rooms, noisy returns, frozen coils, or a unit that feels starved for air.
Cooling Delta-T and Split Temperature Sanity Check
A quick field reference for using return-to-supply temperature difference without over-reading one number.
Electrical references your crew can use on the next call
24V Control Circuit Troubleshooting Ladder
Use this for no-cool, no-heat, or no-fan calls when the low-voltage circuit is the likely control failure point.
Capacitor and Contactor Field Checks
A fast reference for the two outdoor-unit failures you can lose a day on if you skip the basics.
Refrigeration references your crew can use on the next call
Heating references your crew can use on the next call
Heat Pump Defrost Troubleshooting Cheat Sheet
A field-side reference for when the outdoor unit is icing, short-defrosting, or never defrosting at all.
Gas Furnace Sequence of Operation and Safeties
A quick ladder for no-heat calls so you can prove exactly where the sequence breaks.