• WITH reference to your report by Frankie Lister-Fell on the Alexander and Ainsworth estate heating system (Why innovative estate’s heating system is stuck in the past, January 4), Camden say existing gas communal boilers have 15 to 20 years of operational life left in them.

That is because they recently installed new gas boilers rather than going for alternative systems. If Camden persist with this practice of replacing gas with gas, they will never get to the end of the gas phase.

STEPHEN EVANS, NW5