Proper thermostat operation for steam heat

Steam_Heat_Neophite

During a recent call, our service tech replaced the thermostat that controls our late 80s era oil-fueled steam boiler w/ a Honeywell FocusPRO TH5000 Series digital thermostat.  Since then, the boiler has been operating differently than it used to.  Specifically, in the past the boiler fired up when the temperature in the house fell 1-2 degrees below the temp that the thermostat was set on and turned off when it was 2-3 degrees above the thermostat tempeature.  Depending on the outdoor temperature, the system would cycle every 30-60 minutes.  (We live in NC and the winters aren't all that cold here.)

Now, when the temp reaches the exact setting of the new thermostat, the boiler turns off only to fire back up 10-20 minutes later.  In running this way the radiators don't always fully heat.  (They're warm to the touch -- but not hot.) 

Earlier this evening, I spoke w/ a customer service rep at Honeywell to see if I could reset the thermostat so it had a "tolerance" of sort so the boiler would fire less frequently, but run for a longer period each cycle.  He told me that the thermostat could not be adjusted.

Is it okay for the boiler to operate this way?  (It seems really inefficient to me.)  Or do I just need to find a different thermostat?  If so, might you have a recommendation?

Thanks in advance for helping me out w/ this (probably stupid) question. 

Steamhead

Wonder where they are getting their tech support people?

That guy doesn't know his business.



The installation manual is here:



http://www.forwardthinking.honeywell.com/related_links/thermostats/focuspro_5000/install/69_1922es.pdf



Go into the Installer Setup and page to the first stage heat "cycle rate". I bet this setting is on 5. Change it to 2 or 3 and watch how much better it works.



They suggest using 1 for steam, but that can cause temperature swings that are too wide. If your system responds quickly to a call for heat, 2 or 3 will work fine. And if you want to experiment with it, you can.

Steam_Heat_Neophite

You were right!

It was set on "5".  I've reset it to "2" based on your guidance and will let you know how it works.  Thanks, Steamhead, for your very rapid reply and have a good evening!