Use of Hot Water Radiators with mod con and Mult-Temperature radiant

Samriles

Multi-temperature radiant question – mod con boiler with hot water radiators.

Question:  Does continued use of hot water radiators require my mod con boiler to run at full temperature (160-180) thus making it impossible to use outdoor reset controls?  Seems a waste to have purchased a mod con boiler if I can’t use its full efficiency by running at lower temperatures.  But my contractor is telling me I can’t use outdoor reset because he needs to keep temps up for the radiators.



Background:  Have converted my old oil boiler to natural gas, a modulating condensing Munchin boiler.  I have an old single loop hot water radiator system in the house, but am also adding zones for some heat into a new addition, and am adding hydronic heat to the new construction via low temperature quik trak.  Am also reworking an existing room and adding underfloor staple up radiant tubing (needs slightly hotter water). 

CMadatMe

Nutshell Anwser

No you don't have to run that high of water temp througout the heating season. Yes you can run multiple temps. In you case I believe you would have to use the Vision 2 Package from Munchkin. The boiler reset for the cast and the Vision 2 for the radiant.



There are three questions you need to ask your contractor. Where is the heat loss? Where is the radiant design? Where is the heating emiiter output comparison to the heat loss? Without them how does he expect to properly design the heating system that you are paying for.