Burnham hot water furance short cycling

edronline

I have a Burham low pressure hot water/gas boiler for my house.  Model P-209-A-WNI.  manufactured 1994.  It has two zones.



It has been short cycling for the past 2 years.  It is most noticeable on a very cold morning when the furnace has to get the house from about 60 overnight to 65 during the day.  What is happening is that the burner kicks on for a minute or two, then shuts off for a minute, then kicks back on, etc. etc.



I notice no change in my gas bill for these years.  No change in length of time to heat the house.  The registers all seem fine.  The zones are remaining on during this time.  The thermostats read "on" during the entire time.



I have the internal temperature dial set for 180.



To me, I think the heater is saying to itself, "water temp is 180.  Let's shut it down and let it circulate to save money.... wait, now it is 178, let's cut back on and get it up to 180..." over and over again.



Is this a "feature" to save gas, or is this a problem? Is this a sign that my burner is getting old and about to die?



Do I need to change the temperature dial up to down to fix this?  Do I need to bleed the radiators, something I haven't done in who knows how long?  (because I don't really hear any noise with the heater).



Help!



thank you in advance.

Eric_32

Ok...

Lets get some terminology correct, a boiler has water in it. A furnace connects to duct work, has a fan and the warm air is blown thru the registers/grills. If you don't have ductwork then you have a boiler.   



There is a high-limit conrol on the boiler which limits how hot the water gets. Usually it is set to 180° +/-.

If the boiler is too large... the radiators, baseboard put out heat at a slower rate than the boiler makes so the boiler shuts off on Hi-limit so it does not overheat.

If this is something that is recently noticeable, then there may be a flow issue like a valve not open fully, air in the system, (if the radiators are getting hot it is not air), or circulator not working right.

You have 2-zones... how many pumps do you have? If you have zone valves and 1-pump,  you could still get some flow which would warm the radiators (by gravity) even if the pump dies, and it would cause the boiler to bounce off hi limit.