RAPID Hot Water Range Troubleshooting
RAPID Hot Water Range · Support
Troubleshoot Your RAPID
Covers the full RAPID hot water range — SXL, DES, HB, MSH, PTR, VTS and VTX. All models share the same diesel-fired boiler system, pump family, and gun/lance/hose ecosystem. Pick the problem below and we’ll show you the most likely cause, the step-by-step fix, and any parts you might need.
All RAPID hot water models covered
The RAPID range uses a common diesel-fired boiler to heat water on demand. Pump, gun, lance, hose and nozzle issues are identical across all models. Boiler and burner issues are also common — the fuel, photocell, electrode and nozzle service parts are shared. Where a fix applies only to specific variants it is noted in the steps.
1
What’s Going Wrong?
5 Things To Check Before Anything Else
1. Water supply on firstTurn the water supply on and bleed air through the gun before switching the machine on. Never run the pump dry.
2. Diesel levelCheck the diesel tank before every start. Running the boiler dry of fuel leaves air in the fuel line — the burner will need bleeding before it fires again.
3. Power supply110V on a 110V transformer, 240V on a 16A socket, 415V on a three-phase supply. Check the RCD has not tripped. Petrol models (PTR): check engine oil and fuel.
4. Boiler switch sequenceStart the pump first, let water flow through, then switch the boiler on. Switching the boiler on before water is flowing will trip the overheat thermostat.
5. Inlet strainerUnscrew the inlet fitting and rinse the strainer clear. A blocked strainer starves the pump and can cause the boiler to overheat.