How to install system bypass piping

grill_gus

I have a B&G Monoflo hydronic heating system in my house that was installed in the early 1950s. I have cast iron radiators throughout the house. There are two circuits, but only one thermostat, so the system isn't zoned. I plan to install a Weil-Mclain CGa-6 boiler. The installation manual suggests using system bypass piping in order to provide minimum 130°F return water to the boiler. The diagram that seems like it would best suit my system is...

Originally asked by user3080392 on Stack Exchange (diy) (CC BY-SA 4.0).

uphilltech

Great question — answering as the UphillTech team:

I have a B&G Monoflo hydronic heating system in my house well a monoflo (one-pipe) system runs with high return water temperatures to begin with. if you can post a link to the specific manual you are reading so I can see that wording I can provide an opinion on it for you (and get down voted for it here). per your wording of The installation manual suggests ... , um ok... anyway... thing you should know for a non-condensing boiler is that flue (exhaust) gases need to be a minimum temperature to be hot enough to prevent condensation and acid in the flue, and if return water temperature is too low is one thing that can cause that. Which is why minimum return water temp to a non-condensing...

Full answer by ron: https://diy.stackexchange.com/a/329930 (CC BY-SA 4.0).

Need it done for your business? UphillTech.