Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
New boiler. condensing at lower temp with radiators?
I have a couple questions, but I'll give the specs of my system first:
currently, I have a 175000 btu/hr weil mclain cast iron boiler that heats a ~4000 square foot house, with some oldschool standing radiators (160-180°). I also have an early 2000s gas water heater that is getting up there in age. the boiler has already had some issues and needed some replacement parts, so I'm not sure how close it is to end of life, but not too far off. they are both currently gas and vent to the roof.
I want to move their location (for some renovation) and vent out the back of the house, so I figured it's probably time to replace both the boiler and water heater with a newer boiler and a indirect tank.
- am I correct in understanding that a condensing boiler does not get good efficiency above ~140°?
- do condensing boilers typically just run 140° at high duty cycle, as opposed to high temp with more frequent cycles?
- if so, is it advisable to run 140° condensing boiler through old-school radiators? is that a good idea, or will heat transfer suck?
- I currently don't have thermostatic valves on the radiators, just manual knobs. is it easy to retrofit old galvanized pipes with thermostatic valves? is it risky to cut off stuck fittings and re-thread? should I both with thermostatic valves?
- any advice on how to do this project best?