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How long will my boiler last? Looking for your best educated guesses.
You know how when you start out painting the kitchen and you end up doing a full remodel? Like you know, mission creep. Well, that may be what I'm doing here with my radiant system, and I wanted to get some professional opinions on the subject.
So I have a thin slab radiant system I installed 27 years ago when we built the house, and it's been just fantastic, I will never have another kind of heat. The heat source is a Raypak 260 K BTU cast iron boiler that has been flawless (minus a spark module of course). So now what is happening is the vent hood is starting to rust out and no big deal, 200 bucks for a new one and it's done right? (this is where the mission creep part comes in) So I started thinking, I wonder how long this boiler is going to last?
let me back up a little bit, in my view this boiler is dramatically oversized, I run it at its lowest possible temperature which is 105°F and typically the gas valve modulator is running at what must be it's lowest position, very little flame.
I live in California which is a pretty moderate climate, rarely getting to freezing at night. So I'm thinking I could probably get away with about ~100 K BTU boiler and it would be just fine. Obviously take longer from a cold start, but that's not very often. Even then the boiler runs on high for only a couple minutes, because the boiler generates way more heat than the slabs can absorb.
in addition these wall-mounted condensing units are about the quarter of the size of the 260K monster that takes up a good portion of my utility room, so I could also gain some space in the process.
looking at the existing boilers burner compartment, it looks relatively clean, with no signs of any scaling dropping down from the heat exchange tubes and the burners themselves looking good. (I don't see where I can post a picture on this forum or I would)
So my question is, from all your experiences, what kind of service life should I expect from the existing boiler and any other thoughts on going with a smaller condensing unit? And, what brand of wall-mounted units does everybody like?
Thanks for taking the time to read this long post and for any wisdom you may have for me.