What do you guys think of these [URL="http://www.amazon.com/gp/product/B009EDGTXG/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B009EDGTXG&linkCode=as2&tag=ecorenovorg-20"]low cost water heaters[/URL]?
The Good: At $225 they are even cheaper than a tank water heater!! Can use standard B vent, no expensive SS venting required. Works with 1/2" gas lines. Igniter runs off batteries, no electrical hookup required. Simple design, no electronic controls or inducer motors. Doesn't look like it needs a drain connection.
The Bad: Users complain poor temp regulation and questionable support after the sale. Efficiency isn't rated as high as more expensive models.
No edit option on original post, here is the correct link:
I've personally installed several of these. Yes, they're good units, and they work according to advertising when installed correctly. The problem is that some homeowners install it themselves and then complain that they don't work. But the "they" is the person not the heater, lol.
Anyway, Bob, to correct you, they cannot use B vent in many jurisdictions in N. America. That's because, like most gas or LP tankless water heaters, the exhaust contains corrosive condensate. After a few years of use with B vent, a hole will probably form, causing a noxious fume health hazard. Use Class III stainless steel, unless you want to redo the venting every 5 years or so.
The best installation guide I found for the 10L is on this page: https://gadgetsgo.com/Marey-10L-natural-gas-or-propane-indoor-water... . Scroll down to where it says Venting Guide.
You do need a drain connection for longer venting runs, but not for short ones.
Regarding support, sometimes I need to call the manufacturer Marey and never had a problem getting through. Try it yourself at 855-627-3955. It's their toll free number.
Why is B vent OK for standard tank water heaters but not the Marey? 80% and natural draft furnaces have been using b vent for decades, vent normally lasts 20+ years if installed correctly. The cost of The Cat III venting is more than the water heater. A condensing model @ $900 that uses ordinary PVC pipe starts making more sense.
Several tankless manufacturers have switched to allow for CPVC and PVC, for sure an easier and cheaper material.
Why is B vent OK for standard tank water heaters but not the Marey?
Which ones? I don't know of any. That's because all tankless heaters produce condensate, and it's corrosive.
Anyway, many/most tankless manufacturers (Eccotemp, Rheem, Paloma, Rinnai) also require the Class III SS on many of their current models. It's not just Marey.