We have jobs paying higher than the average plumber salary! It could also be caused by low pressure, and you can rule this out by checking your boiler’s pressure gauge if the pressure is lower than , you may have a pressure issue. Every engineer in our network is a friendly, gas safe registered installer with plenty of experience fitting boilers they'll keep the house nice and tidy while they work, too. Q why do i need a replacement boiler? If you think there.