Economy 7 for water heater not working!

[Manish]

Hello,
I have Tribune Premier 180E unvented Water Heater and the economy seven water heating has stopped working and are running the water on emergency. My gut feeling is that the immersion element has concked off as all the rest seems fine. I must admit that the heater hasnt been serviced in years and probably the limescale has got to it. I have got a quote to replace and service (if at all its the immersion element) for 370 pounds (which includes 270 for labour)!
My question - Should I replace the bolier all together (probably with a similar unvented direct heater like Stanton 210E) or should I get this one serviced with parts repalced? Which option would be better in terms of cost and relaibility would be better? Someone please advise.

Thanks