Can go well but will also fail to ignite - out for 1 minute to 24 hours. I think installer and subsequent trades persons do not have experience and can not adjust settings. Could be fault davey HP Torrium 45-05T pump 17m. surface dist. from low point at tank. Pump 1.2m. above tank floor, house floor above tank floor 2.4m. Heater is approx. 22m. thru walls from pump to house side.