I have an oil fired steam boiler system and my household hot water is also heated via heating coils within the boiler. When the thermostat calls for heat, I can hear the relay send a control signal to the boiler, however the boiler seems to be cycling on/off intermittantly, thus not creating enough steam pressure to push steam into the pipes since the PSI gauge generally doesn't register any pressure being built up in the boiler.
I do seem to get limited hot water however... the thermostat for the hot water is located on the boiler but that has also been a problem... possibly the boiler stays on long enough before cycling off due to the problem but still allows some time to heat up the coils?

I recently had a cleanout 3 wks ago and I told the technician of the symptoms. He flushed the oil line and said that was most likely the problem as there was either air or particulate matter in the fuel line causing it get intermittant instead of a steady flow of oil. The fuel filter was replaced. He also indicated it could occur if the water level was at or about the low water cutoff, however there was and is plenty of water in the tank. Well, that didn't seem to resolve the problem... since the problem has persisted and become even more intermittant since now I do not register any PSI and have no heat. Could it be something to do with an intermittant control signal from the control unit and is that seperate from the call for hot water, possibly a plugged nozzle, something to do with a sensor for detecting the flame??? Or could the fuel line be plugged or air in it again? If the latter is suspected, how would I flush the line myself and prime it?

Any advice would be much appreciated! I'm Cold!:)) Elena:confused:

Playing with a boiler is like with trouble. The unit was not acting up when the service man was there before so I would give him another try to figure it out. There are many safety controls on steam so you do not want to mess around unless you know what you are doing.

Have you checked the water level?