Hello. This issue has started recently. I have a Dunkirk oil fired boiler. It's a 2 zone system. I have Honeywell Pro 5000 thermostats. My issue is that the thermostats are calling for heat when the thermostat is already at temp. For instance. Thermostat says 70. The thermostat does the audible click noise indicating that the heat is on. The boiler fires up for 2-4 minutes. Not nearly enough time to circulate water to every rooms baseboard. All of the baseboard heaters are producing heat out of them. Some are warmer than others. Then after 2-4 minutes the thermostat clicks off and the boiler shuts down. Then typically 15-30 minutes will pass until the thermostat calls for heat again. All while maintaining the 70 degrees on the display. The only thing that I could say that has changed since this started happening was that I had to turn my main water off for a couple minutes a few days ago to change out a water filter. The system doesn't seem air bound. All pipes to the zones and the supply and returns are all hot. I'm stumped.