Tankless Heater Installation - Contractor Talk - Professional Construction and Remodeling Forum

Ramblinwreck · 07-20-2008, 01:01 PM

Got a problem I need some help with. Customer wants to replace his old gas hot water heater with a new tankless one, probably Rannai, but I got a problem. He needs between 6-8 GPM for his two-story 4 bedroom home and to achieve that output we need a 3/4 inch gas supply. That wouldn’t be a problem I’d just run a new line but the existing HW heater is in his attic, it would take me a week just to run the line.

So, he and I thought why not put the new tankless heater in his crawl space, it’s about 5 feet in places. The gas meter is about 20 feet away so running a ¾ inch line is a breeze and just tie into the existing hot water line in at his kitchen sink. Then cap off his existing HW heater and gas supply in the attic. The hot water supply would essentially be reversing its flow. Anyone see any issues with this??

Thanks.

22rifle · 07-20-2008, 01:11 PM

GET A PLUMBER WHO KNOWS WHAT HE IS DOING!

YOU HAVE NO BUSINESS DOING THIS JOB!

I hope anyone giving you technical advice is prepared to accept the liability his advice carries if you kill someone.

Bill · 07-20-2008, 01:13 PM

Quote:

Originally Posted by 22rifle

GET A PLUMBER WHO KNOWS WHAT HE IS DOING!

I hope anyone giving you technical advice is prepared to accept the liability his advice carries if you kill someone.

I highly reccomend getting someone who is licensed and experienced. We just had a talk on another forum about an unlicensed handyman who caused the death of a child due to a gas explosion.

KillerToiletSpider · 07-20-2008, 01:17 PM

If you can't spell Rinnai you probably have no business installing it.

Bill · 07-20-2008, 01:38 PM

Quote:

Originally Posted by KillerToiletSpider

If you can't spell Rinnai you probably have no business installing it.

good one, I did not spot that one KTS

silvertree · 07-20-2008, 02:01 PM

If he strapped the heater to the meter, he could just run a power steering hose to the gas and water supply. A few clamps and your in business. But make sure you get a permit first and always have the work inspected. The clamps must be stainless steel of course or it won't pass inspection.

Ron The Plumber · 07-20-2008, 02:22 PM

Those straps have to be copper plated or it will cause a corrosive build up.

22rifle · 07-20-2008, 02:29 PM

Quote:

Originally Posted by Ron The Plumber

Those straps have to be copper plated or it will cause a corrosive build up.

I thought they had to be lead coated.

Ron The Plumber · 07-20-2008, 02:31 PM

They can be but you have to ground it 1st.

22rifle · 07-20-2008, 02:54 PM

Quote:

Originally Posted by Ron The Plumber

They can be but you have to ground it 1st.

I heard you have to ground it to the sewer. Is that true?

Ron The Plumber · 07-20-2008, 02:57 PM

Yep use that green wire that you see in the trench.

Bill · 07-20-2008, 03:25 PM

man, have I been messing up. I been using the black wire to ground with!

Grumpyplumber · 07-20-2008, 03:29 PM

I see two options for the fella.

1) Get a plumber and sleep at night knowing it was done legitimatly & insured.

2) Look around online until you can find a DIY site that might give the correct information from a total stranger (most plumbers won't freely oiffer this kind of advice), hope you did it right and try to ignore the fact that if anything goes wrong with it over the course of 7 years, the statute of limitations for a criminal act aren't up yet.

One small detail on the gas, venting or even the temperature could land you in court...with luck, it's only civil court.

Grumpyplumber · 07-20-2008, 03:30 PM

Quote:

Originally Posted by USP45

man, have I been messing up. I been using the black wire to ground with!

HIRE AN ELECTRICIAN!

plumberman · 07-20-2008, 04:45 PM

Thought it was the red one?? Or maybe the blue?? Guess I should call the OP over to figure it out for me!

flashheatingand · 07-21-2008, 06:01 PM

I am not a plumber. I do HVAC work. The plumbers advise does seem valid, this stuff is not rocket science, but you need to know what you are doing (just like hvac, or electrical). Having said that, you can call the gas company and request a 1lb meter and install pressure regulators on all gas appliances. This will allow you to use the existing gas line.

But, read up on this. Because if you mess up, you could do a lot of damage.

Bill · 07-21-2008, 06:07 PM

Quote:

Originally Posted by Grumpyplumber

HIRE AN ELECTRICIAN!

an electrician? What, are you crazy? he is the one that started the water leak on the never ending story thread!

22rifle · 07-21-2008, 06:52 PM

Quote:

Originally Posted by flashheatingand

I am not a plumber. I do HVAC work. The plumbers advise does seem valid, this stuff is not rocket science, but you need to know what you are doing (just like hvac, or electrical). Having said that, you can call the gas company and request a 1lb meter and install pressure regulators on all gas appliances. This will allow you to use the existing gas line.

But, read up on this. Because if you mess up, you could do a lot of damage.

Good grief! Don't tell this guy anything about gas systems like that. He HAS NO BUSINESS TOUCHING it. Period, end of sentence.

Besides, you have no business trying to give advice to begin with. A 1lb meter? What in thunder is that?

Look, I know you meant well. But we are trying to keep people from getting KILLED here. And you are hurting the cause.

PS. Yes, I know what you meant when you said a 1lb meter. Ain't no such thing however. First of all, they don't set the pressure at 1 pound. Second of all, it ain't the meter that controls the pressure.

Bill · 07-21-2008, 07:14 PM

Quote:

Originally Posted by 22rifle

Good grief! Don't tell this guy anything about gas systems like that. He HAS NO BUSINESS TOUCHING it. Period, end of sentence.

Besides, you have no business trying to give advice to begin with. A 1lb meter? What in thunder is that?

Look, I know you meant well. But we are trying to keep people from getting KILLED here. And you are hurting the cause.

PS. Yes, I know what you meant when you said a 1lb meter. Ain't no such thing however. First of all, they don't set the pressure at 1 pound. Second of all, it ain't the meter that controls the pressure.

darn, I was going to install mine that way

plumberman · 07-21-2008, 08:41 PM

not rocket science? But yet a one pound meter and an exsiting line will do the trick

Its not science its just common sense. HIRE IT OUT!