Best Of

Let’s backup for a moment and get some basic info.

Was a Manual J load calculation done to determine the heat loss? If so, what are the results?

What size is the boiler?

I see 4 loops on one manifold and 3 on the other. What are the tube sizes, the spacing and their lengths on average?

The reason that I’m asking is that unless you’re in a mild climate, it looks like that you may be under-radiated, in which case you’d need some supplemental emitters. If so, that would change the approach.

I apologize for not asking these questions first, but I went directly to addressing your questions without noticing the number of loops.

If you are switching to resistance heat often, your COP or efficiency may not be what you assume.

Some installers add a small Kwh meter on the HP to see what it is actually consuming.

If the resistance is in fact being used or over used, the LP starts to look better.

Some GEO issues are not easily fixed if you have a well, pond, or loop field that is not up to the task.

All this is knowable with some number crunching.

As they say there is no free lunch. The free boiler will cost you more than getting the right unit.

The issue is all the bits you need to make this work properly will be near the cost of a new modcon. If your fuel source is expensive like propane, the operating cost delta is not worth the effort (properly set up modcon will use about 25% to 30% less fuel with radiant).

"The entering temps from the loops vary. Normally 35 in winter and 72 or so in summer."

To me that's a severe red flag that the well is insufficient, or something is wrong with the way it's piped. If the well water is only 35F in winter there's almost no heat available before the water freezes. In Pennsylvania I'd expect the year-round ground temperature to be in the low 50's and the well water should stay at that temperature if the wells are property configured.