Replacement boiler sizing

bdub

Have a 120,00 btu input/ 99,000 btu output 63 year old raypac boiler. Can I replace it with a new non condensing wall hung 88 btu output Navien model? we use between 30 -40 day or nights a year. Thanks in advance.

EzzyT

I would stay away from any Navien products. The current boiler chimney vented or power vented?

If chimney vented have the chimney inspected to ensure it’s sized right zero obstructions and good condition.

Jamie Hall

Well… you could. However, is that the right size boiler? How do you know? Hot water system boilers should be sized in accordance with the heat loss of the structure, and that should be calculated before you go looking for a new boiler.