Thought I'd share this information as it might help someone expereincing a similar problem.
We program our central heating to shutdown overnight.
During the recent cold spell, we cranked up the thermostat to keep warmer. We started experiencing problems where the boiler would not start up in the morning because the pressure was low. We had the engineer out several times. He replaced the Pressure Relief Valve. This did not fix the problem. On his last visit he was talking about replacing the boiler.
We have the boiler programmed to shutdown at 22.50. Right up to that time, the boiler is going flat out to keep the heat up. At 22.50, the whole system shuts down immediately, both the burners and the circulating pump. As the boiler has been working so hard right up to that point, its internal elements are very hot. As the pump is no longer circulating water through the boiler, the water in the boiler boils and the pressure relief valve releases water and steam from the system. So in the morning the pressure is too low for the boiler to fire.
Anyways I am circumventing the problem by manually turning the thermostat down 5 minutes before the system shutdown time and this has cured the boiler startup problem. Now the cold weathers gone, we probably wont need the heating up so high anyway.
The boiler manufacturer (IDEAL) says the boiler is working OK. The boiler controls are not their responsibility. I haven't been able to identify the manufacturer of the controls. The control system should definitely ought to keep the pump going for at least 5 minutes after the boiler shutdown.
We program our central heating to shutdown overnight.
During the recent cold spell, we cranked up the thermostat to keep warmer. We started experiencing problems where the boiler would not start up in the morning because the pressure was low. We had the engineer out several times. He replaced the Pressure Relief Valve. This did not fix the problem. On his last visit he was talking about replacing the boiler.
We have the boiler programmed to shutdown at 22.50. Right up to that time, the boiler is going flat out to keep the heat up. At 22.50, the whole system shuts down immediately, both the burners and the circulating pump. As the boiler has been working so hard right up to that point, its internal elements are very hot. As the pump is no longer circulating water through the boiler, the water in the boiler boils and the pressure relief valve releases water and steam from the system. So in the morning the pressure is too low for the boiler to fire.
Anyways I am circumventing the problem by manually turning the thermostat down 5 minutes before the system shutdown time and this has cured the boiler startup problem. Now the cold weathers gone, we probably wont need the heating up so high anyway.
The boiler manufacturer (IDEAL) says the boiler is working OK. The boiler controls are not their responsibility. I haven't been able to identify the manufacturer of the controls. The control system should definitely ought to keep the pump going for at least 5 minutes after the boiler shutdown.
