Specifications ("tolerances") invariably include a safety factor. You should be fine at 180 but you can always try it at 160-170 - if the old boiler kept your home warm at 160, then you should be fine.

The historical problems with PEX were mostly related to the connections rather than the tubing itself. These have long been fixed.

Thank you. I agree with you. The only thing holding me back from lowering the temp is I do see/feel a difference. The heat coming from the baseboard heaters feels warmer and the system seems to run for a shorter period of time. I love the feeling of extra warmth....how much of that is psychological is up for debate. 😄

You should speak with your heating contractor for verification and clarification. Also keep in mind that your boiler system might have an ‘Outdoor Reset’ function that automatically turns the supply water temperature down when the outdoor temperate rises and only uses 180˚F at Design Temperature. Water that leaves the boiler at 180˚F looses heat as it travels through the system, when the pipes are not insulated and the return water can be 10˚F to 20˚F lower than the supply side temperature.

Speak to your contractor, ask about outdoor reset, have them explain how your piping system is configured and what else you should know about it.

IMPO

SR

If 160 degrees worked fine with the old boiler and there were no other changes, there should be no reason why the setting should be any higher with a new one. Setting it too high uses more energy than needed, wastefully.

Setting it at the max sounds like a Neanderthal HVAC tech practice - "no one ever calls to complain during heating season that their house warms up quickly and easily maintains the temperature setting", only when it doesn't. But they don't pay the energy bills. The same dumb attitude appears concerning oversizing equipment.

If the temperature setting is easily changed, I'd try to drop it and see how that works. Stuff like this isn't rocket science.

HVAC techs tend to do the same thing with water heater temperature settings for new equipment, in my experience. The first thing I do after having a new heater installed is to drop the temperature setting.

Thanks Elmer. I think you are right. I am going to lower the boiler temp. It is an easy thing to try and see what happens. The old one had no trouble keeping the house warm at 160, although on the coldest days of the year it certainly ran a lot longer - shocking, I know. LOL.