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View Full Version : Am I getting good recommendations from these contractors?



DanielNJ
09-25-2009, 12:51 PM
I'm about to replace our old oil-fired boiler with a high-efficiency gas model.

We've had three contactors come out to measure and offer proposals, one of which was was done last year and is no longer being considered. But all three recommended a boiler in the 100,000 BTU range for our 2-story colonial house in suburban NJ with a finished basement and attic. I hope since at least the sizing estimates all agree, they are correct.

Both of the current proposals recommended a Peerless Purefire PF-110 boiler. The other brands they mentioned as alternatives were Buderis and Weil-McLain. I believe those are the brands they can get most easily from their suppliers, and are the ones they usually work with. Does anyone have thoughts for or against any of these choices? What about the Peerless Purefire vs Peerless Pinnacle? It looks like both of those are high-efficiency models from Peerless that qualify for the government tax rebates but the proposals didn't even mention the Pinnacle -- is one a better choice than the other?

Next, our current space is kind of tight so both current installlers have recommended small indirect water heaters in the 30-32 gallon range. One suggested either a Buderis or Superstor, the other recommended a Peerless Partner to go with the Peerless boiler. When I expressed my doubts about such a small water heater, both installers suggested they're "like a 100-gallon conventional water heater" and "should provide an endless supply of hot water". When I continued to press them, one installer said the only difference between the 30-gallon size vs larger indirect sizes was flow rate. The other guy said the only difference was recovery rate (the bigger ones recover faster, he said). None of which seems to agree with what I've read here or elsewhere! Is there any truth to these statements or are they just trying to steer us to the smallest indirect unit because that's what's easiest for them to fit into our existing space? When I asked one of them about using a tankless Bosch instead, he warned me that it would "not last a year" due to hard water buildup. Really?? What I really suspect I should do is tear out part of an adjacent closet and go with a properly sized indirect water heater, but I don't feel like I'm getting the accurate info I need to make the right choice. We've been spoiled by the tankless coil in the old oil-fired boiler, and we are accustomed to taking a couple of back-to-back 10-15 minute showers while sometimes even running the dishwasher at the same time without having to worry about it at all. Am I wrong to think a 30-gallon indirect water heater would not be up to that task?

Thanks for any insight.

beenthere
09-26-2009, 05:40 AM
A small tank should work fine. I prefer a larger tank.

ut, A 100,000 BTU boiler at 80% efficiency should give you a recovery rate of roughly 100 gallons an hour at 100°F temp rise.
So with 30 gallons in the tank. You would have 130 gallons of hot water you could use.

DanielNJ
09-29-2009, 03:33 AM
I don't think I completely follow. Does it really recover so quickly during use that you can run multiple showers and a dishwasher continuously for an hour and not notice any temperature loss as long as you haven't used up 130 gallons yet?

Let's try another scenario. Say I fill up a 50-gallon bathtub. The water comes out of the tub filler pretty fast, so the first 30 gallons is going to be depleted from that tank pretty quickly, isn't it? Does that little indirect tank really keep up fast enough to maintain hot water flowing into that tub after you've depleted the initial 30 gallons, even at that quick rate of usage?

I guess what I'm asking is if a 30-gallon indirect tank can do that, what's the point of the larger sizes?

beenthere
09-29-2009, 05:17 AM
Yes, When set up right, they can recover plenty of water for multiple showers. And or long showers.
Recovery rates are generally in excess of 100 gallons an hour.So with 30 gallons in storage. You have a lot of hot water available to you.

DanielNJ
09-29-2009, 10:49 AM
So again, if a 30-gallon indirect tank can do that, what's the point of the larger sizes? You said you prefer a larger tank - why?

beenthere
09-29-2009, 03:39 PM
Less cycling from heat to hot water generation on colder days. When it might be under a heavier heat and hot water demand.