Hardly surprising though is it. Who would have thought that newer technology, electrically far more complex, would be more unreliable to begin with than a combustion engine that's had a century to be perfected/refined reliablility wise?
My 25year old gas boiler far outlived my brother's condensing boiler than had a corroded heat-exchanger after just 3 years. Far more reliable, but an awful 65% efficiency. We need the technological progress, and the reliability will catch up.