Tankless water heater attic venting

[chuckd83]

I'm replacing a 40 gal. tank water heater in the attic. I'd rather not have to move the old one down and lug a new one up the drop down ladder. So I'm thinking of installing a tankless one. 2 bathrooms, kitchen sink, dishwasher, and washing machine.

The old tank water heater is vented through the roof. I measured the opening and it's 9 inches through the roof and the pipe is about 3 1/2" outside diameter.

Is there a tankless water heater on the market where I can use the existing venting? I know it requires more air intake, but the attic has two large gable vents on either side.

Thanks for any help.

 

[Plumber69]

I'm replacing a 40 gal. tank water heater in the attic. I'd rather not have to move the old one down and lug a new one up the drop down ladder. So I'm thinking of installing a tankless one. 2 bathrooms, kitchen sink, dishwasher, and washing machine.

The old tank water heater is vented through the roof. I measured the opening and it's 9 inches through the roof and the pipe is about 3 1/2" outside diameter.

Is there a tankless water heater on the market where I can use the existing venting? I know it requires more air intake, but the attic has two large gable vents on either side.

Thanks for any help.

I'm pretty sure you can but you would need to have something made up with flashing to make it leak proof. I've never heard of a hot water tank in an addic. If I was you I would hire a company to do all the moving for you. Tank less are pricey unless your installing it your self

 

[Sponsor]

 

[Plumber69]

Get them to bring 2 up there and the old one down. Now you have a backup when the other fails

 

[Themp]

My neighbor had a small 40 gallon gas water heater in his crawl space. It failed and he was told that no one makes a small one any more to fit. His options were an electric or a tankless gas in his crawl space. He went with the tankless gas and it has been a pain for him. If I were you I would replace the one you have and not go tankless. If you do not want to bring the old one down, then just move it to the side somewhere in the attic.

 

[MACPLUMB]

I'm replacing a 40 gal. tank water heater in the attic. I'd rather not have to move the old one down and lug a new one up the drop down ladder. So I'm thinking of installing a tankless one. 2 bathrooms, kitchen sink, dishwasher, and washing machine.

The old tank water heater is vented through the roof. I measured the opening and it's 9 inches through the roof and the pipe is about 3 1/2" outside diameter.

Is there a tankless water heater on the market where I can use the existing venting? I know it requires more air intake, but the attic has two large gable vents on either side.

Thanks for any help.

NO ! to take care of that size of house you would need at least a 6" vent though the roof,
with a deadcaed 3/4" gas pipe coming from the gas meter,
you are looking at at least $2000,00 for the proper size heater anything less and you will not get enough hot water to run more then one fixture at a time

 

[Jadnashua]

Depending on the distance to the gas meter, you may need a 1" gas line (depending on the on-demand, tankless unit). Most of those have electronics in them and probably won't like the summertime attic temperatures, either. I can see the potential space savings to putting one in the attic or maybe the garage, but since both of those locations are usually not heated or cooled, they pose the possibility of freezing in many parts of the USA (maybe Hawaii excepted). A tankless system may have freeze protection logic built-in, but it's not like a tank that is full of hot water...it is essentially 'off' and cold when no demand. If your power goes off during a storm, no hot water, no freeze protection. A typical gas WH will still make and keep the water hot.

 

[chuckd83]

Thanks all. Upgrade gas line and venting. I guess I'm left with coming up with a way to get the old one down and the new one up without breaking my back.

 

[Dj2]

A new water heater is at least 130 lbs. and 2 strong dudes may be able to lift it up.

Advice: 1. Empty and remove the old one first.
2. Raise the new one and fill in the water when it's installed.
3. Replace the flex pipes or at least the washers, gas flex and perhaps the gas valve. Shut off valve - it it's leaking.
I assume you knew those.

BTW, placing a water heater in an attic, in places like TX, NM, AZ, CA is a way to enjoy hot water for free most of the time.

 

[Plumber69]

A new water heater is at least 130 lbs. and 2 strong dudes may be able to lift it up.

Advice: 1. Empty and remove the old one first.
2. Raise the new one and fill in the water when it's installed.
3. Replace the flex pipes or at least the washers, gas flex and perhaps the gas valve. Shut off valve - it it's leaking.
I assume you knew those.

BTW, placing a water heater in an attic, in places like TX, NM, AZ, CA is a way to enjoy hot water for free most of the time.

Placing a hwt in an attic seems like a stupid idea to me