Combustion noises too loud; rumbling noises.
Faults that are not displayed
Worcester Bosch Greenstar 2000 Combi
Remedy
▶ Check the gas type.
▶ Check the gas supply pressure.
▶ Check the flue system; clean or repair if required.
▶ Check the gas/air ratio.
▶ Check the ratio control valve; replace if required.
▶ Check condense drain is clear.
▶ Check fan depression.