Keeping your home heating devices active during the warmer summer months is the best way to stop radiators not heating up after summer. You should look to switch on your central heating system for a few minutes every few days even in hot summer conditions, to keep the hydraulic components of radiators and other appliances somewhat active.
Other good practices include commencing with an annual boiler service in summer, and using inhibitor regularly to make your designer radiators less susceptible to a build up off sludge or rust.
To find out more, take a look at our blog, Why are my radiators not heating up after summer?