Residential steam heat issues

Whitney

We have an old two-unit house (c. 1870) which has two gas furnaces. The one in question is a new Burnham (installed in Jan. 2000). Our tenants moved out in September and we made the mistake of not keeping the heat on. Ever since firing it up again at the beginning of this month, it has been cycling. The company we use has been here at least 6 times but is unable to figure it out. Before calling them, we drained the system ourselves and replaced all of the radiator valves. I know they have done the following: installed a new thermostat in the apartment, replaced most of the wiring from the thermostat to the furnace, and done a general cleaning/maintenance to it. There may have been other things, but they didn't detail it. As it stands now, the furnace goes on for about 5 minutes then shuts off for another 5 or 10, then goes back on again. The thermostat in the apartment is set to 78 degrees and the current temperature is 70. We have tried lowering the thermostat request to 68 but then it doesn't heat to more than 63 or 64. (Here in Maine, we need a little more). There is plenty of water in the system (sight glass is 2/3 full when system shut off to recoup the water) and there is a low water shutoff. This is a one-pipe system. A friend has suggested there could be "air bounce" from when we drained it. Could this be it and if so, how do I remedy it? If this isn't it, what do I do???!!! My new tenants are being patient but getting fed up! Thanks for any information!

Unknown

Check these things first....

http://www.heatinghelp.com/newsletter.cfm?Id=130