why does the thermostat keep shutting of the boiler after a couple of minutes, when it is not even hot. the boiler is a harcal 430 with a honeywell thermostat and relay

c browne, February 2008

if your harcal 430 cuts out to lock out after approx 15 seconds its goinging to be,
Photo - cell, photo cell connections or leads it but it may just need reseating because most of them sit lose in there seatings, try that if that does not work it could be anything does thre boiler fire?

james, April 2008