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steph746

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Hello Everyone,

I need some general advice for a water heater purchase. I had a plumber recently come out to our home to have a look at our setup. We purchased our home a few months ago, began some renovations, and are now ready for a water heater to be installed soon.

First off, I'm still debating between direct vent, chimney vent and also a tankless water heater. The plumber that came out seems to be leaning towards a 50-gallon (or so) water tank with a mixing valve that with a power vent. I'm not so keen on the power vent because I can imagine it will be noisy. We do have a chimney nearby and I believe the current water heater is being vented through that. So, my first question is which way to vent is better? Is one more expensive than the other to install?

Our simultaneous water needs will normally be running showers (family of 4), possibly at the same time as a dishwasher and washing machine, then having enough hot water to fill a bath.

The plumber recommend a tank with a mixing valve on it.

Then, still looming out there as an option, is a tankless water heater. Our only concern with this is that it may not be able to handle the simultaneous tasks.

Thanks in advance for pointing me in the right direction...
 
I'm not a plumber but never could understand a power vent. My new house I replaced a tankless with a 50 gallon gas water heater. On my old house I replaced my 50 gallon gas water heater with a tankless. IMHO, never consider a tankless unless you have natural gas. Lastly, there is more maintenance with a tankless water heater, but I live in So Cal, where the weather is much easier and we don't have harsh winters.
 
If it were me I would go with standard chimney water heater. I don't like tankless but to each their own. The power Venter would require a new vent to be placed outside and I find that those water heaters don't last as long as traditional tank types.
 
So, direct vent would mean another opening would need to be put alongside the house? And power vent would mean the tank uses electrical power to vent? Which option would be the most efficient in the long run? It seems that tankless water heaters are the most efficient, but I'm not sure if it would be able to handle the load of our house (even though it's not that high). My parents have a tankless and it seems that it takes a while for hot water to begin to flow. It could be because it's an older home and there are other factors involved...
 
Yep, power vent means the installation of a plug nearby, if you don't have one already. Do you have natural gas available? That is the biggest question.
 
Yes. I would be looking for a natural gas water heater. Kind of overwhelmed by the options out there. Was told that Bradford White, AO Smith or State water heaters were the best options...leaning towards direct vent vs. tankless.

You can't have a direct vent going out a chimney, right?
 
Direct vent can't normally be in a chimney. Typically they vent separately with a special two pipe system. They are overly expensive IMHO

Power vent has two PVC pipes that must be vented to exterior of home in proper location. Also pricey

Standard vent may be able to use your existing chimney. Price is still reasonable but 50 gallon is as big as you can get now.

Tankless will need two vents like powervent typically although other styled are available. Properly sized two showers shouldn't be an issue, and you can take them back to back forever. You will most likely need to upgrade to a 3/4 gas line directly to heater and ensure proper gas meter/piping sizing throughout house. You also will have to understand and expect cold water sandwiches with most tankless systems.
 
I see. I think what is installed now is an atmospheric vent that is going out the chimney. You are recommending just getting another atmospheric vent? Are they more efficient now than 10-15 years ago? What about a mixing valve?
 
I was told by the plumber that a mixing valve would help with water efficiency. Doesn't it help a lot?

You're saying just go with another atmospheric tank heater? Why not direct vent?
 
I was told by the plumber that a mixing valve would help with water efficiency. Doesn't it help a lot?

You're saying just go with another atmospheric tank heater? Why not direct vent?

Imho direct vent sucks, it's basically a power vent with no power. I wouldn't recommend one.
 
Are power vents very loud? The blower would be on constantly or would it be more like small intervals of time? How is the efficiency of a direct vent vs. power vent since power vent uses electricity?
 
Why a mixing valve? Do you heat with the same water heater?

I was told by the plumber that a mixing valve would help with water efficiency. Doesn't it help a lot?

The theory of a TMV (Thermal Mixing Valve) is very simple. It not only extends the supply of hot water but also prevents bacterial growth in the water heater.

TMV (Temp Mixing Valve) _2.jpg

TMV (Temp Mixing Valve) _1.jpg
 
I'm not sold on those mixing valves. Maybe for someone who is on a non-treated well, but those of us who live on domestic, chlorinated water systems, it seems you are wasting lots of energy to heat that water to an unbearable temperature, only to sanitize, then blend this same water with non-heated, bacteria ridden water? What am I missing?
 
Are power vents very loud? The blower would be on constantly or would it be more like small intervals of time? How is the efficiency of a direct vent vs. power vent since power vent uses electricity?
A customer of mine had a WH in a closet off the master bedroom. The power vent ran when the burner was on to heat water. I thought it was loud during the day. I'll bet it sounded a lot louder at 3 AM.
 
* I'm not sold on those mixing valves.

Maybe for someone who is on a non-treated well, but those of us who live on domestic, chlorinated water systems, it seems you are wasting lots of energy to heat that water to an unbearable temperature, only to sanitize, then blend this same water with non-heated, bacteria ridden water?

*What am I missing?

OK... Let's try it this way-

ALL water contains bacterium (except treated - TMV-direct POU chlorination/H202-UV-RO). Chlorine will not completely kill all bacterium (and micro-organisms). That is why most municipalities have gone to chloramines.

Cold water carries dormant organisms. They become active as water temp rises. Hence a 120 degree WH is a perfect host for bacterium growth. 142 degree kills the bacterium for the most part.

The cold water introduced into the TMV hasn't the time to allow that bacterium to grow in the house distribution system (although it will).

Whether municipal or well, no water is pure and it magnifies its' impurities during distribution/storage.

By not pre-filtering water to a WH, the sediment(s) provide an excellent food source for the bacterium multiplication.
 

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