Hi, we have an aircell ho****er electric to gas. This issue i have just started to have is the electric stops working, and water goes cold. It doesnt trip any switches just stops, gas doeznt fire up when the electric stops. Push reset and all good, i can turn gas switch and red light goes on until the electric kicks in and takes over. In the last two days it has turned of, possibly thermostat , any ideas?

More than likely, partially blocked gas jets. They should be removed by a qualified gas fitter who would use a correct size ring or open ended spanner. The fitter would either use the correct size tip cleaner just like the one used to clean the tips of oxy torches, they often suck on the jet as this is more effective than blowing. The jets would then be reassembled by the qualified gas fitter who may have had to view a YouTube on this as they may not have been familiar with that type of heater.