[I]saves [/I]recently brought up the subject of multi-staging boilers in another thread which got me thinking (again)... [QUOTE=saves;1921227]I have installed seven heating systems using Tekmar controls.... One commercial job with base board and cast iron rads. and two mixing valves with two oil boilers staged. [/QUOTE]I'd be interested in hearing more about that installation when you get a chance. What kind of commercial property is it? Do the boilers provide DHW to the building? What kind of piping arrangement did you use? How is the venting of the two boilers handled? I have limited knowledge of multi-staging boilers, but it sounds intriguing. My main reference point right now on the subject would be [URL="http://www.pmengineer.com/Articles/Cover_Story/22fdde8f55298010VgnVCM100000f932a8c0____"]THIS[/URL] article.

We have a one level bungalow with no basement heated by infloor radiant heat. The heavy duty hot water tank is run by natural gas. There is a large white thermostat attached to the infloor heating components and from my understanding from the previous owner is set to stay at 110 degrees. When taking a shower this am i noticed that the water is not as hot as normal (not cold , so after checking the thermostat it shows 80 degrees. Not sure where to start with trouble shooting, is it the hot water tank; just the thermostat or something else. Our infloor heat is working and we have hot water. Not sure if this is normal from time to time or a sign that the heating element in the hot water tank is going. The hot water tank is a rental so that would be easy to get done, do I need to call a heating contractor regards to this or call the company that rents us the hot water tank. Sorry about the long post but more info i give is better for me not being the best handyman on the block :) [IMG]http://farm8.staticflickr.com/7166/6569218905_fcd7c46c55_b.jpg[/IMG] Thanks Paul Merry Christmas