Okay, here's the situation: I've got a 1955 gas-fired boiler in the house we just bought last year, chugging along fine, just very inefficiently (40-60% are the guesses I've heard). I'm looking at replacing it with something really efficient. The clay tiles in the current flue are shifting, too, so I'd have to re-line it if I went with a natural draft boiler and/or wanted to keep the existing stand-alone, natural draft gas hot water heater. Since I'm planning on being in this house for the long haul, I'm willing to invest in getting the most efficient boiler I can afford (direct vent mod-con with outdoor reset) and changing out the water heater with an indirect (so I can abandon the flue).
My brother-in-law's a licensed plumber with 20+ years in the business, more plumbing than boiler I believe. Rest assured, he'll be doing the install. I'm a pretty fair DIY'er, but my biggest asset is knowing my limits.
Since he's doing me a really big favor, I'd like to do as much of the design research as I can to help. I don't know how much experience he's got with setups like this, plus I'm the type that like to know what I've got in my own house. So I've been doing a lot of reading here (you guys are a great help!) and on some other sites and I've got a few questions that hopefully one of you can help me with.
The house (northern NJ) has two zones currently: one in-slab copper radiant in a family room with it's own thermostat, a second zone for all the fin convector baseboards in the rest of the house. I'd like to plan for up to two additional zones in the future, since we'd like to eventually finish the basement (another baseboard zone, I'd assume) and remodel the kitchen (where the wall that currently holds that room's baseboards might get replaced with cabinets, so I'd assume we might do staple-up radiant at that point). I can't see us ever needing more zones than that, much as the wife would love an addition too.
Given that I'd like to allow for those 4 zones, that I'd like DHW priority for the indirect tank, and that I've got a mix of radiant and baseboard, any suggestions on controls? My brother-in-law said he likes Peerless boilers, so the Pinnacle is what I'd be looking at. I can see from the install manual that Peerless has an option for an interface to a modulating controller for outdoor reset and dual set points. They mention either the Tekmar 263, 265, or their own Pavilion 410. Can any of those control up to 4 thermostats? Would I need a system with more than two set points, or can the convectors run the same outdoor reset-controlled temp as the radiants (the current slab + the possible staple-up)?
I called Tekmar briefly and they mentioned their 423 system with a zone manager, but wouldn't that be overkill? Their application diagram A 263-2 looks like exactly what I'd want for the two zones I've got today (just with one boiler). But would I be painting myself in a corner if I do add zones in the future? And any recommendations among those products, or anything similar that would accomplish what I need that I should look into?
Second question's a quick one, hopefully. Since I'll be abandoning the current chimney, I'd like to run the PVC vents up there to avoid having to go out the side of the house. It's a 20' shot straight up, so I think we can do that with the Pinnacle. I've read a bit on using the abandoned flue for running the new PVC vents, but nothing that tells me what to do with the top of the chimney once you've got the PVC up there. Do you just leave the flue open to the rain above? Or does somebody make a cap with two holes in it for 3" PVC? Mortar around the PVC somehow to make a rain cap? Just drill two holes in the existing stainless steel cap that's on there now? Or is this ultimately a question for the inspector when you file the permit application?
Thanks in advance for any suggestions or recommendations you can give!