How do I comparison shop for a new furnace?

April 19, 2022 3:31 AM

My trusty 1980s furnace is finally getting replaced after years of service with a combination heat and hot water boiler. The heating company I've chosen has given me three options from different manufacturers, and I'm finding myself at a loss for how to choose between them. Are there unbiased review sites for this sort of stuff? My point of contact is trustworthy, but the purchase is a hefty chunk of change and I want to do my own independent research in order to make a decision.

Here are the nitty gritty details in case it's a factor, listed from most to least expensive, although with only $1000 difference, price doesn't seem to be the most important variable:

• BOSCH Greenstar Combination 131 Wall-mounted Condensing Boiler
• VEISSMAN Vitodens Combination 100-W wall-mounted condensing boiler
• RINNAI Combination i120CN Condensing Boiler

posted by jeremias to Home & Garden (14 answers total)

I had to replace a high efficiency boiler after only ten years because it needed constant maintenance to keep going, was not reliable, and the replacement parts were crazy expensive. So ask your HVAC company about reliability.
posted by metasarah at 5:08 AM on April 19, 2022 [1 favorite]

I’d also be asking about what the options are for getting heat pump replacements for these. It may be out of budget but within the decade I expect will be the standard approach. At the least it will be good to know what that would entail.
posted by meinvt at 5:58 AM on April 19, 2022 [3 favorites]

Perhaps you can get an answer if you ask in /r/hvac.
posted by ShooBoo at 6:00 AM on April 19, 2022 [1 favorite]

I might look at the parts cost for all three as a way to compare how much total cost of ownership might be.

But I'm really with meinvt on the heat pump here. For every unit of gas that you put into the boiler it makes ~90% of that gas into heat. With a heat pump you're moving heat around rather than generating heat, for every unit of electricity you put in you might get four units of heat. Heat pumps can work in VERY cold environments now, so if someone says "The winters round here are too cold for heat pumps....." they're talking about heat pumps from 20 years ago, not current ones.
posted by gregr at 6:29 AM on April 19, 2022 [3 favorites]

Oh, also it looks like your location on your profile isn't public, so I won't directly link, but if you search for "your_state heat pump rebates" you'll see some significant rebates.
posted by gregr at 6:34 AM on April 19, 2022

We (UK location) were faced with this last year and went for Greenstar due to reviews, availability of servicing and parts. And it's been pretty good so far! I do think though that heat pumps are the future, but - even with goverment schemes to assist with installation - it cost around 5x the combi boiler. We think that's where we'll go in 10 years, but for now this was the best option for us.
posted by freya_lamb at 6:37 AM on April 19, 2022

We did this purchase several years ago, and we went with a combination of word-of-mouth, local plumbers' experience, and cost.

We bought an IBC I believe, for combined baseboard heating and all our hot water. (Located in New England, FWIW.)
posted by wenestvedt at 6:50 AM on April 19, 2022 [1 favorite]

You want /r/hvacadvice. Regular /hvac is a technician support group that does not welcome customer questions.
posted by hwyengr at 7:34 AM on April 19, 2022 [3 favorites]

There may be rebates for splits, heat pumps, which also provide AC. Before you make this big purchase, maybe talk to an energy efficiency expert.
posted by theora55 at 7:38 AM on April 19, 2022 [1 favorite]

I believe consumer reports recently reviewed boilers. A while back we chose to install some state of the art type boilers and while they were great while they worked we really had trouble finding someone who knew how to work on them. There is something to be said for a workhorse type boiler that every plumber has experienced and may have parts to in their truck. Once you pick one you might want to call a few local plumbers and ask if they are knowledgeable about them.
posted by InkaLomax at 7:57 AM on April 19, 2022 [1 favorite]

[Also UK]

I have a Worcester-Bosch combi boiler of a similar type and it's been great for the past five years.

Passed every service with flying colours, touch wood.
posted by doornoise at 8:13 AM on April 19, 2022

Response by poster: > There may be rebates for splits, heat pumps, which also provide AC. Before you make this big purchase, maybe talk to an energy efficiency expert.

Thanks, yes, I didn't want to overload the original question with data, but the house has had a full energy assessment, rebates are all set up etc.

> We did this purchase several years ago, and we went with a combination of word-of-mouth, local plumbers' experience, and cost.

We bought an IBC I believe, for combined baseboard heating and all our hot water. (Located in New England, FWIW.)

As I'm doing the research, there's a substantial group of HVAC folks who do *not* recommend the combination boiler/hot water systems that I'm looking at (apparently there's a higher rate of failure, harder to service/find parts, etc.)

So I'm now asking the company to prepare a separate estimate/recommendation for the "traditional" system of the individual boiler plus the individual hot water heater. Curious if anyone else with experience in combination units have any anecdotal data on how they've fared over time.
posted by jeremias at 9:52 AM on April 19, 2022 [1 favorite]

As I'm doing the research, there's a substantial group of HVAC folks who do *not* recommend the combination boiler/hot water systems that I'm looking at ...

So when someone asks me, an IT guy, what computer to buy, I only reply, "Who's going to support you? Do whatever they tell you."

I am the same way with major appliances: if I have a reliable, honest tradesman, I will follow his guidance -- because when I need help, he's the person I will call. If I have ignored his advice during selection and installation, I get a lot less sympathy/effort from him when it breaks!

When our unit leaked a little water one time, they had a guy over IMMEDIATELY. For another issue they sent a guy the next day -- and he not only cleaned it out and checked over the whole system for nothing, he gave me extra consumables in case it happened again. (It did not happen again.)

I don't want to jinx myself by saying it's problem-free, but it's been much more reliable than my central air-conditioning.
posted by wenestvedt at 10:35 AM on April 19, 2022 [1 favorite]

I am the same way with major appliances: if I have a reliable, honest tradesman, I will follow his guidance -- because when I need help, he's the person I will call. If I have ignored his advice during selection and installation, I get a lot less sympathy/effort from him when it breaks!

This is sound advice. With complex projects like the installation of a new HVAC system, the quality of the installation work is much more important than the brand and model of what they install. A reputable contractor will not offer to install subpar equipment. A lousy contractor may install a top of the line unit and do it so poorly that it performs like garbage.
posted by TrialByMedia at 7:30 PM on April 19, 2022 [2 favorites]