Gas and Oil Home Heating Furnaces - Boiler Pressure Rising, Have Done Everything To Fix

My boiler pressure continues to rise after the furnace has stopped firing. The temperature of the furnace is set to 140 Hi. I have replaced the expansion tank and the feed valve as well as all of the relief valves around my 2 story home. I have 2 zones. The furnace continues to tip and 30 PSI and expel hot water out of the back. I don't know what else to do - help is needed. Had a plumber here today and he was stumped as well. PLEASE HELP

Thank you

My boiler pressure continues to rise after the furnace has stopped firing. The temperature of the furnace is set to 140 Hi. I have replaced the expansion tank and the feed valve as well as all of the relief valves around my 2 story home. I have 2 zones. The furnace continues to tip and 30 PSI and expel hot water out of the back. I don't know what else to do - help is needed. Had a plumber here today and he was stumped as well. PLEASE HELP

Thank you

Perhaps a valve shut in the line to the expansion tank that you might have missed or maybe a blockage in the pipe?
Sounds like you've replaced what normally causes this.

My boiler pressure continues to rise after the furnace has stopped firing. The temperature of the furnace is set to 140 Hi. I have replaced the expansion tank and the feed valve as well as all of the relief valves around my 2 story home. I have 2 zones. The furnace continues to tip and 30 PSI and expel hot water out of the back. I don't know what else to do - help is needed. Had a plumber here today and he was stumped as well. PLEASE HELP

Thank you

Perhaps a valve shut in the line to the expansion tank that you might have missed or maybe a blockage in the pipe?
Sounds like you've replaced what normally causes this.
Did the problem just arise?
Might be helpful if you could post some pictures on photobucket.

I am going to try and get some pics. This problem started about a week ago - prior to that, nothing. Always consistent pressure.

I posted some pictures of my system here

marcusippboilerpics (http://www.consistentconsulting.com/boilerpics/marcusippboiler.htm)

A bad expansion tank and feed valve were the two best guesses as to the cause of this problem --- and still are, I would say. But guessing doesn't really cut it --- you need someone who can analyze the problem and test the various possible theories to determine which is actually causing the problem.

Sorry the plumber couldn't help. You may need someone who specializes in repairing hot water heating systems.

Usually there is a valve that bypasses the automatic fill valve to alllow the system to be filled rapidly --- I don't suppose that could be open?

Is there any other connection to a pressurized source of water? Do you use the boiler for heating potable hot water?

Thanks - I called a local supply shot that doubles as a an 'advice shop' - he suggested the coil in the hot water maker was probably leading causing the constant pressure rise. Sure enough, turned off the feed valve to the hot water maker and that did it - the pressure is normal.

Does your boiler have a tankless coil & the boiler stays hot all the time?

No oil on the boiler - I have an AMTROL hot water maker and right now, all signs point to there being a link in the coil within it - I am testing the theory as we speak