Triangle Prestige internal CH pump speed and ODR hi limit effect?
Attachment 17463Just hooked up outdoor reset on our Triangle Tube Prestige 110 boiler. I'd appreciate recommendations regarding the Prestige's internal circulator speed setting. Specifically I'd like to know whether running it on low speed would provide adequate flow through the boiler. I realize there are factors to take into consideration. All near boiler piping (1") is according to the TT manual with Primary Secondary. Three radiant zones each use their own 3 speed Grundfos circulator and manifolds to monitor flow. Loop lengths are within spec using predominantly subfloor pex in plates. The 110 boiler is oversized for our heat loss of 70K BTU, but it supplies a Smart 40 gal. indirect tank also. I ask about reducing the internal pump speed because the boiler cycles slightly more than I prefer in the fringe season (currently 40's) if not all zones are calling for heat. I thought that a low internal pump speed would permit the secondary zone pumps to pull the heat from the boiler to reduce short cycling. I'd rather not increase the secondary pump speeds in order to preserve electricity costs. My biggest concern is harming the boiler or reducing it's longevity.
One more factor. Previously, without ODR enabled, the boiler's hi temp setpoint was 140* for condensing. It's kept our home warm for two winters. I only increased the hi temp limit to 150* after hooking up ODR. Factory default is 186*. Would changing to the higher setting have any impact on boiler cycling? Thanks for any help.