Tankless Water Heater

School me. Just noticed my water heater is starting to let go, so it's time to replace. Considering tankless as an option. Would be replacing a standard 40 gal electric. Home is a 4 bed 3 bath with a family of 4, but we do have guests pretty often, so it's not uncommon to have up to 8 people in the home needing to shower in the mornings, etc.

 

Rinnai seems to be the go to brand around here. Though, I think gas is the preferred heat source.

 

You’re gonna need a fuck ton more ampacity than your current electric is pulling to power an electric boiler. As the guy who makes money pulling big wire to electric boilers, it’s nothing I would ever consider for myself.

 

Just get some of those little chickenshit heaters I see in Brazil a lot that mount right on the shower faucet. They heat the water as it comes out.

 

Didn't think about that aspect.

 

Electric is going to take a massive amount of power. If you can put in a gas fired unit it may be worth it. Installation also requires a special double wall air intake/exhaust stack that wants to be within about 20 feet of the unit ideally (costly setup). If you can do an exterior install it gets simpler.

 

No one ever does, then I’m the asshole for telling them they can’t run an 80A boiler off their 100A service, so for the 200A upgrade and wiring their boiler they’ll be in for about $4k

 

Same issues for gas. If I'm not mistaken, most houses don't have an adequate sized gas line. And there is venting to worry about if you are replacing a non direct(powered) venting heater.

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If you have the infrastructure in place or are doing major renovations, they are great. We have Rinnai, one elect upstairs and one gas downstairs. IIRC, when we renovated, switching the cooktop from elect to gas and the difference between 1975 AC compressors and current tech gave us adequate amperage for the electric.

Can you switch the current elect for gas? Recovery time is quicker. Low flow shower heads help too.

 

I'm in the same boat. Bought a house 4 months ago and the electric water heater says installed in 06/99. From what I understand standard service life is usually not over 10 years so I'm afraid its going to flood my basement any day.

Can you vent a tankless gas heater "sideways" out near the foundation? I want to put it in a utility room in the basement and that vent type would be fairly easy. If I have to go straight vertical out the roof I'm screwed.

 

You can vent sideways (ours does, but not near grade) and the units can be installed on the exterior.

 

We have relatively common power outages due to weather. I like the reserve supply of hot water that a traditional water heater allows.

 

I'm mystified why people want tankless water heaters. They cost a lot to install, and there is little/no cost savings to running them (install and operation cost over life of unit) compared to a quality tank unit with a proper insulation jacket.

Both have about the same useful lifespan.

Unless you live in one of those 300sf tiny houses, I don't understand the desire.

A properly sized and installed tank unit will always be cheaper to own.

 

Inspired product placement on HGTV has made tankless trendy. Nobody who does their due diligence would select one.

 

There are places where they make sense. On-demand warm water for an isolated powder room sink at the far end of the house, for instance.
But the whole-house units just don't cut it.

 

Thanks guys...Just scheduled to have a 50 gal tank put in by a plumber I know. Maybe if I ever build new construction, I'll consider tankless.

 

And the instant hot water feature they offer can be accomplished with a standard unit and a programmable recirc pump. Our new place has this, and given its about a 100 foot run from the heater to the shower we use, it works well.

 

Not to mention the normal homeowner will never backwash to eliminate scaling, etc.

The only place our plumbers recommend them is for very large soaking tubs and maybe small cabins that don’t get a ton of use. Even minor point of use stuff in commercial applications they still go with small 6-10 gallon tank water heaters.

 

We have one in our new house. Not a fan of it. It’s gas fired but the control panel is 110 powered so when power is out no hot water. Two Bathrooms that are way off on other end of the house takes a while to get hot water to them. Rinnai is the brand.

I’d rather have a conventional hot water tank and deal with replacing it every 10 years.

 

My Powerflex 50gal stays warm off just the pilot light. If one takes a normal shower, it doesn’t even kick on. And, we’ve lost power for consecutive days and always had hot water for bathing.