My boiler has started shutting down too soon. It runs for about 1 min and then waits 5 mins to start again.
It's a Potterton Envoy 80. The three thermistors which check flow, return and dry are all OK. The pump is running OK, too.
The result is that the rads warm up very slowly as a "plug" of heated water circulates followed by tepid water as the boiler waits its standard 5 mins.
Ideas? Naffer