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How to Choose a Good Hydronic Heating/Cooling Contractor

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Our friend, Mark Eatherton, writes:

There has been some discussion lately here on The Wall about how a homeowner knows whether the person and or company they are dealing with is qualified and skilled to do a proper job of whatever the task might be, and this includes boiler replacements, hydronic additions, radiant additions, etc.

Inasmuch as 95% of the world comes here seeking answers, I think it would be a great idea to come up with a list of questions that the homeowners could and should ask of their bidding contractors so that the homeowners at least have a chance of getting the system of their dreams that works without issues and doesn't cost an arm and a leg in energy.

So let's put together a list that homeowners coming here seeking advice can use in moving forward. What are the right questions they should ask their potential contractors when it comes to the proper installation of a system?


Steamhead has this to say:

Here are a few to start:

1. How did you select this boiler? (Answers: If it's steam, by the installed radiation, plus some extra pickup if some radiators were removed; If it's hot-water, by doing a proper heat-loss calculation)

2. I have a steam system and part of the house doesn't heat well. How do we fix this? (The WRONG answer: Raise the steam pressure)

3. I have a steam system and the banging is terrible! (WRONG answers: 1- They all do that, and 2- Let us rip it out and put in forced-air)

Your turn.

Ironman says:
  1. Definitely ask for references and photos of other jobs.
  2. Check licensing. Particularly specialty licensing: plumbing, HVAC, electrical.
  3. Ask what specific specialized training he or she has: radiant, solar, manufacturers, etc. as it relates to the proposed work.
  4. How is he or she determining the size of equipment or components? Rule of thumb, same as the old, heat loss calculation, radiation survey, Wild Ass Guess?
  5. Ask if he or she knows what the universal hydronics formula is, and can he explain it. This one will eliminate probably every hack out there.
  6. Does he have a digital combustion analyzer and has he been trained how to use it? This could be asked about any other specific tool that's mandatory as it relates to the type of job.
  7. Does he have insurance?
  8. If it's a boiler replacement, will the necessary accessories be included a: fill/back-flow preventer, expansion tank, new circulator, MBR. If it's steam: LWCO, proper header,venting, skimming,etc.
Gordy advises:

Ask to see pictures of previous work. It's not hard to tell professionalism from hack work. Some good Wall of Shame hack pics vs. a well-done Wall of Pride job photos will give you a gauge as to how a job should turn out, Sadly, some work can look nice but function improperly. Always avoid the bidder that says he or she can put heat in your house for X dollars and won't provide details. And I don't just mean the name of the boiler they'll be installing.

Paul48 writes:

I think the first question should attempt to sort out the qualified contractors from the "Wall of Shame" Rembrandts. That question should be, "Do you consider your company to be heating system specialists?"

To which Hatterasguy (with tongue in cheek) replies:

"Of course we do, Paul48. We have installed thousands of boilers during the past 30 years we have been in business. In fact, here is a photo of one of our most recent installations"

7782679d8f245843a050471edca576"Note the new circulators, the Spirovent air separation control, and brackets that secure the piping to the wall. Also, note the temperature sensor that lets the boiler know the temperature of the supply water."

"We are experts at heating installations"

(As I said, tongue in cheek.)

So Paul48 comes back with . . .

And the rest of the questions should sort through the BS. It is a starting point, and to sort out the contractors that don't know anything about modulating-condensing boilers (which we call "mod/cons," or modern heating systems. If an honest man, says that he installs a couple cast-iron boilers a year, there's nothing wrong with that. Beware the fast shuffle - no time to talk, very busy, and needs a down payment to get things going.

Harvey Ramer says:

Whatever is done concerning recommendations on who to hire, or licensing, or anything of that sort, the young entrepreneur should be kept in mind. If the gauntlet one must face in order to strike out on their own is too mountainous, it will keep many otherwise excellent professionals, from being able to offer their individual services and provide healthy competition in the marketplace. Too many times a tradesman's professionalism is judged solely by the amount of time spent doing a certain task.

In my opinion, there are a couple things a customer should ask:

First and foremost, does the contractor posses the capital to see the job to completion and handle any unfortunate mishaps. In keeping with this train of thought, also ensure that the contractor has adequate liability insurance and any other insurance the job entails.

References are the gold standard for assessing an unknown's quality of work, business ethics, etc.

As far as choosing someone specifically for hydronics, be very interactive. Strike up a conversation on the subject. Discuss different systems; Radiators, Baseboard, Radiant Floor or Ceiling. Ask the contractor how the different systems perform and what can be expected from a comfort standpoint. Ask him which boiler best matches which system and why. Understand that every hydronic system has a unique character and that your contractor is in essence, the manufacturer and engineer of your comfort system. Being as such, make sure you are also receiving a decent labor warranty on the entire system from the contractor. Proceed with caution if a contractor answers a question with this reply; "Well, we've been doing it this way for 30 years." He likely doesn't even know why. Remember, this is an interview and every contractor you talk to may not be a true hydronic professional. Most hydronic professionals are just looking for someone to talk to about their profession. A good one will answer your questions promptly and directly with an explanation if you are willing to listen.

If you just really talk to the contractor and pay attention to how he answers your questions, you will know within 15 minutes whether you have the right one.

Homeowner, JosieT, had this excellent advice:

I'll give the 'ignorant' homeowner's point of view of what I wished I would have known.

  1. Any contractor who makes a recommendation without knowing the intricacies of the house - air infiltration, age, plaster or sheet rock - can't do an adequate heat loss.If you have bad windows like I do (old single pane), and they don't even mention that, something is seriously wrong. Or even to not check the age of the windows if you have double pane is not wise. The best contractor will also check if you did an energy audit to assess the infiltration.
  2. Ask to see the heat-loss estimates. I used this layman's calculator after the fact to do my own 'dumb' estimate. It's not Manual J. But it gives some ballpark. Make sure he/she does a thorough heat loss. Most make a wild educated guess.
  3. Don't be shy to see their work. A happy client will be delighted to send pictures or do a reference call.
  4. Do they know all the heating emitter options and when to use what? I had many plumbers (even third generation licensed plumbers) who never heard of panel radiators. Recessed sunrads are very popular in my area (Long Island), but recessing them while looks better does require additional BTU to be added to the heat loss. Also I was surprised to find to find out that panel rads were equivalent in price to sunrads and much nicer looking. The ones who did know of them were quick to say it's too expensive probably because of lack of experience.
  5. Do you really need a combi boiler? When I got quotes, four out of six people recommended a combi. None explained the hot water limitations. I would never do a combi boiler in a house over 1,500 sq feet. They don't save that much space and need more servicing which isn't cheap. They are all the rage where I live. I had two people who went the traditional route and I unfortunately thought that since they were in the minority, so their plan was subpar. Majority doesn't always rule.
  6. Be careful about radiant floor staple-up under wood floor. It sounds good but what a mess if not done well. Also the creaking PEX is irritating.
  7. More zones isn't necessarily better. I have eight zones for a 2,000 sq ft house. I needed two, max three. The added zones add no real value. My house isn't so big that I need run it cooler in one part vs another. I thought I'd run downstairs lower at night. It doesn't pay and then it takes all the more longer to heat it back up.
  8. Don't ever ever ever let a contractor diss a steam system especially in an old house. If they do this, run! Back to #1 - every house is different! There is no one-size-fits-all rule.
  9. While price shouldn't be the decider, I found that high price doesn't always equate with getting the best result.
  10. Be an educated consumer on any major changes to a house. Don't put your trust completely in a contractor. They won't live in the house. They won't be paying the bill for the heating system. Don't feel that someone with a business knows more that you can learn. I'm not much more educated in hydronics than long time plumbers. Also every single person you talk to will have a different opinion. I think i've talked to 20 'experts' on my situation, each one was different. That's why education is important for the homeowner.

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