Which boiler should I choose? Burderus GB 142 or HTP Elite FT 80?

I will have the plumber install our new boiler . I have several came to our home and give us difference quote. Many difference opinion , we don't know which one is the best. There are 2 plumber who we trust most and they are local business, told us to put in the Burderus GB 142 or Htp Elite Ft 80.
Anyone here can help me and please give me advice to choose the boiler?
Thanks so much.
Kate Kelly

I have a Buderus unit in my townhouse that has been working fine. The US headquarters for Buderus is in Londonderry, NH, so both expertise and parts are close by. The biggest thing is to choose the proper size. Even though the units can modulate, if it is too big, it is too big and won't be anywhere near as efficient as it should be. Do NOT just replace with a boiler the same size, in most all cases, it will be 2-4x oversized. To get the best economy out of the thing, it needs to be right-sized, and that means it should run all the time during the heating season at just the right heat output that matches what's lost to the outside. If it is too big, it turns on/off, and each cycle wastes energy, plus, each cycle wears things out faster. I have bascially, their smallest unit (and a 60-gallon indirect so I can fill a big 6' soaking tub), and it could stand to be smaller. It did cut my heating bill by about 1/3 over the old unit (the rates keep changing, so a direct comparison is harder just using costs).

If a boiler is properly sized, on the coldest design day, it would run 100% of the time to keep the house warm. A boiler that only ran 1/2 time would be probably at least 2x oversized, and no, it isn't more efficent at that. Being able to modulate means it can run close to 100% more of the time as the load changes throughout the heating season. Obviously, it can't run 100% every day, but the goal is to let it do that as much as possible, and getting the right-sized unit is critical to that and saving money. Plus, the smaller one starts out less expensive, too in parts.
If they haven't done a room by room heat load analysis, they're doing you a disserivce.

I have no experience with the HTP unit, it might be great, just don't know.

Thank you so much for your advice, yes we do have the pro plumber came to our home and measure our home. We have around 2000 sqf of living space, he told us should need around 80,000 BTU. The old one we have, it is 2x oversize for what we need. I heard lot of plumber talk about the Burderus GB 142 have problem with electrical. It is scare me of to install them ... I try to search customer review about Htp Elite Ft 80, but I have no result because this is new produce just came out 3 months ago. I'm not sure how is it work?!?...
Thanks again for your advice.
Kate Kelly

Measuring the square feet is NOT an acceptable way to determine the size boiler you need. I have a small townhouse (1100 sq ft), and could have gotten by with about a 25K BTU unit on the coldest day IF they made one that small (they don't). The 80K is probably still too big unless you have no insulation and leaking windows! Even if it modulates, most days, you'd cause it to turn on/off because it won't go low enough. Remember...max efficency = run all the time at just enough output to maintain temp of the house. To do that, it needs to both go low enough and high enough...for most, high enough isn't a problem, but low enough is.

Kate kelly said:

Thank you so much for your advice, yes we do have the pro plumber came to our home and measure our home. We have around 2000 sqf of living space, he told us should need around 80,000 BTU. The old one we have, it is 2x oversize for what we need. I heard lot of plumber talk about the Burderus GB 142 have problem with electrical. It is scare me of to install them ... I try to search customer review about Htp Elite Ft 80, but I have no result because this is new produce just came out 3 months ago. I'm not sure how is it work?!?...
Thanks again for your advice.
Kate Kelly

Click to expand...

I have ~20% more living space in a mostly 1-story circa 1923 bungalow, and it needs less 40KBTU/hour of boiler output to say warm, in a locatoin, with an outside design temp a couple degrees cooler than Dover NH. With an 80K boiler I'd be good down to about -65 to -70F, a temp that I'm sure we've seen here (if not very often since the last ice age. )

A 40BTU/foot house in Dover would be a ridiculously sub-code house with almost no insulation, lots of drafts and air leaks, and mostly single-pane windows. Look around- if that's what you have, spending the money on tightening up and insulating the place will be more cost-effective than spending it on a condensing boiler, and provide more comfort too.

The modulating boiler with the lowest minimum-fire will run more efficiently, with fewer burn cycles and last longer than a bigger boiler. The HTP Elite Ft 55 would probably be more appropriate than the -80, with a min-fire input of 13KBTU/hr rather than 17KBTU/hr for the -80.

The smallest Buderus GB142 is the -24, with a min-fire output of about 25KBTU/hr in condensing mode, 23K in non-condensing, either of which is more than half my design condition load. It's great boiler, but not an optimal choice for my house- there are several boilers out there with lower min-fire output (eg, Triangle Tube Solo-60, Peerless Pinnacle T50.)

If you have any wintertime gas bill with the fuel use and meter reading dates by which it can be correlated to weather data, it's pretty easy to put an upper bound on how big it needs to be. I'd be surprised if you need anything as big as either of those boilers, and smaller is better for efficiency, comfort, and long-term reliability. But it's fairly simple arithmetic to turn therms per heating degree-day into BTU/hour at design temp, if you're able to share some of the billing information (and your zip code, to be able to use the nearest and most accurate weather station data.)

Choose the contractor not the boiler.

Start by asking them for a sample of their heat loads. Ask suggested the units proposed seem too "big". You must have educated, local support, but we have installed condensing boilers made by Buderus, Burnham, Crown, ICB, HTP, Lochinvar, Triangle Tube and Viessman with great results. The smallest units (lowest input) are the HTP Contender, Lochinvar Cadet, Triangle Tube Prestige 60 and the Bosch Greenstar 57.