Regular Safety Checks
All modern steam boilers have multiple safeties installed to ensure safe operation, even when things go wrong. These safeties are designed to do 2 things: keep the proper amount of water in the boiler and keep the pressure of the boiler at a safe level.
All newly installed steam boilers should have a minimum of 2 pressure switches installed. The first one, generally, should be a vaporstat. This will be the operating pressure controller and will keep the boiler operating at the pressure that the system is designed for once it is set.
The second pressure switch is a manual reset pressuretrol. The pressure on this controller is set to the maximum pressure you want the boiler to ever see. The controller should also not be able to be set higher than 15psi. Once the pressure in the boiler reaches the max set pressure it will shut off the burner, and it will not allow it to relight until the reset button is pressed. Now, before this button is reset a thorough investigation needs to be done into why the boiler was able to generate so much pressure. This may include flushing the pigtails or testing the operating pressure controller.
Steam boilers also have 2 Low Water Cut Offs installed. Similarly to the pressure controls, one will keep the boiler at the normal operating water level. It can do this by either: cutting the burner and allowing water the drain back until the level rises, or by calling a condensate pump to add water to the system. With either setup this firs LWCO needs to shut the boiler off if the water level drops below an acceptable level. There is also a secondary LWCO that has a manual reset. If the water level ever gets this low something very wrong has happened and the boiler will shutoff and not restart. A very thorough investigation is necessary to see what is wrong.
These low water cutoffs require regular maintenance. Luckily it's very simple. You'll see above there are 2 different models of LWCO. The yellow handle is used to flush the water from the boiler and remove contaminants which will clog the safety and prevent it from shutting off the boiler. This valve needs to be flushed on a weekly basis at minimum in order to keep the float inside the safety moving freely. You can see a photo of what happens when the float isn't regularly flushed.
When the LWCO if flushed the burner should turn off and water should come out. If either of these things doesn't happen it's time to call us and we can determine the fault and safely fix the boiler to keep everyone warm.
