Cheap Tankless Water Heaters
Hi. I am in zone 4a. Building a 28×80 shop/cottage. The entire building is going to be very air tight for a shop building. Of course, it will be sealed to the peak between shop and cottage.
I am wondering why the tankless units that have name brands are $1000 +/-yet I also see some on Amazon for about $100+/-?
I cannot justify the extra $900, so I was just going to find a recycled electric tank water heater; but, if I can use one of these $100 tankless units on propane, it might make sense to go tankless.
My buddy has a high endntankless propane unit and it uses PVC pipe to feed fresh air and even for the exhaust. I like that it is so efficient that the exhaust heat is so low it does not melt PVC. I wondered if this was the difference between cheap and name brand units.
Thanks for your advice or even a link to anything that explains the difference.
-Mike
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Replies
I suspect the cheap ones have pretty thin heat exchangers that would rot out pretty fast, and other cut corners. And who knows what their parts & support will be like 1+ years down the road. I'd stick with known brands, not these "pseudo-brands" that keep appearing and disappearing on Amazon.
Damage may not be covered by insurance if an appliance is not UL or CSA.
Tankless heaters can range from very simple to very complicated pieces of equipment. The low cost ones you see are typically non-condensing without any fancy controls, these are very common outside of north America. Not the best efficiency or comfort, the water temperature is mostly set by you, turn the water flow rate low, water gets hotter, turn the flow low enough the unit shuts off. Works ok for a shower but not the best for small draws.
A friend of mine uses one for heating a kiddie pool during the summer, simple hookup to the existing BBQ connection, lot cheaper than a pool heater.
For a workshop, keep it simple, I would stick to an electric tank. Mount it up high above the sink, instant hot water when you need it. No need to run gas lines or exhaust pipes. Simple to drain down if you need to shutoff the shop heat.
I would avoid buying any off brand equipment that has ANY potential safety risks on Amazon or Ebay. Amazon and Ebay are full of cheap knockoffs and random other junk that doesn't meet specs or is otherwise questionable. If a tankless water heater ruptures, you risk severe water damage and possibly a house fire. Is that risk worth $900 to you? Keep in mind also that insurance companies will sometimes deny coverage in case of a claim involving an uncertified piece of equipment.
A good example of junk stuff sold on Amazon and Ebay is a lot of the network cable (category (cat) 5E, cat 6, etc.). Much of it is "CCA" (Copper Clad Aluminum). They like to tell you how it "meets all the specs of cat (whatever it claims it is) cable. That's a lie. The IEEE are the people who write the specs and they SPECIFICALLY state the cable MUST use a SOLID COPPER conductor. CCA isn't ANY cat-rated. Anyone who says otherwise either doesn't know what they're talking about or is outright lying to you.
Be very careful buying anything questionable from unreliable sources. I know that electronic components sold on Amazon and Ebay are often remarked parts, which is basically a form of fraud.
Bill
Yes, the sale of unsafe products on Amazon is rampant and disturbing. I miss the days when the Sears catalog was the equivalent source of low-cost products shipped to your home, and pretty much every listing for something electrical said "UL listed" at the end of the short catalog description.
A standard 40-gallon electric water from one of the big box stores is a little over $300. But if the shop and cottage are connected, can't you serve both spaces with one unit? How much hot water does your shop need?
Steve, my plan is to have one water heater for both locations. You can see the general plan in the pic. I will save $250 or more by recycling. Fortunately finding manufacture date is not a problem and people remodel houses and remove good tanks, so I will go that route since I am building for pennies by scrounging materials over the last few years. No debt and super deals and not much compromise on the parts that I cannot redo easily such as foundation, framing, air sealing, and insulation. Things like light fixtures, paint, or even a HW heater is an easy upgrade later.
I picked up 56 gallons of Glidden paint and primer in one for a $1 a gallon. I picked up about $15K in OSB for $1600 in 3x8 sheets. I will have to spend a little bit more for seam air sealing, but the savings are huge. I picked up 16 brand new light fixtures for $2 a piece. They are not very attractive, but easily changed later.
Oh yea, I am building shop-cottage and once we are out of camper, a 1400sq ft house.
A can of paint or a sheet of OSB isn't likely to blow up on you. So I would be cautious about looking for a bargain water heater. If a plumber I knew and trusted vouched for the unit, I might consider it. But I would probably opt to find my bargains elsewhere.
Good point Steve. Thankfully, I have more confidence in my engineering skills to test a thermostat and overpressure valve than I do most plumbers.
A Takagi T-H3M-DV-P condensing tankless runs less than $700, a non-condensing $550.
That's a lot less than $1000, but you get a quality water heater.
Thomas, I will have to read up on condensing vs non-condensing for the future. Thanks for the tip. Although, from an enconomics standpoint, I think what DC Contrarian points out is a factor-my desire to save every penny possible and still have little regret means I will lean toward a 40 gallon electric tank unit.
Well, this discussion has been helpful for me, because I learned about the Takagi tankless water heater, which led me down a rabbit-hole reading about using it for hydronic heating as well as domestic hot water, and I think it might be just the thing for a project I've got coming up. So thanks for starting it!
I got a stiebel eltron instant water heater off Amazon for under a 1000 3 years ago and it is running good. However it first came completely broken. I had to call the manufacturer, and Amazon. They ended up reimbursing me for installing the unit twice. I guess what I should be saying is get a good reviewed brand and buy it somewhere else besides Amazon. It is a fascinating piece of equipment though it’s about the size of a textbook and can run 2 1/2 hot water appliances at once
Over the years I've bought a lot of cheap off-brand stuff from Amazon, Ebay and their cousin, Harbor Freight. For the most part I've been happy. But I don't think I'd go for a water heater in a home.
If the water heater fails, and you live with other people, you are going to be under intense pressure to get it fixed NOW! The installation of water heaters is not at all standard, I spent $150 on fittings and about four hours on my last one. Put those two factors together and you're really going to want a unit that can be repaired rather than replaced, one where you can buy repair parts. There are some things where you can say, "if it breaks I'll just buy another and still be ahead," but a water heater isn't one of them.
There's no guarantee that a name-brand appliance will have parts availability or even honor their warranty -- I've had horror stories -- but the chances are better.