Thread: tankless water heater install

HVAC guy mounted and vented this unit, he is no longer on this job.

I believe this is a Samsung unit. I can't always trust a subcontractor's information, I could not find the installation instructions, but there appears to be several issues: can you use PVC for venting?, shouldn't it be level?

Any comments, links or PDF's (for tankless installs in general) would be greatly appreciated.

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I can't really see much of the unit in the pictures, but.... The PEX is wrong so I would bet the install of the WH is not up to spec either.

You should be able to Google some install guidelines. I have some in my office, if you don't find them I might be able to post them tomorrow.

This site seems to link to everything you want to know.

Tankless Water Heater Buying Guide

Cant help you with the Pex as it does not exist around here.

I love the vent on the drain pan

Looks like extension cord in the back.

I haven't looked at the above linked info, but you can use PVC for venting for at least one manufacturer's water heater.

Originally Posted by Scott Patterson

I can't really see much of the unit in the pictures, but.... The PEX is wrong so I would bet the install of the WH is not up to spec either.

Scott,

Pex is wrong?, I'm embarrassed to ask, but how?

if you don't find them I might be able to post them tomorrow

.

I was looking specifically for venting, which my be why I couldn't find anything, (it was obviously not lack of internet skills ), if you could post them that would be great!

Here are the only other pictures I have,

Originally Posted by Bob Elliott

Looks like extension cord in the back.

Could be, still under construction.

Not my house (well it is now), not my subs.

Originally Posted by chris mcintyre

HVAC guy mounted and vented this unit, he is no longer on this job.

I believe this is a Samsung unit. I can't always trust a subcontractor's information, I could not find the installation instructions, but there appears to be several issues: can you use PVC for venting?, shouldn't it be level?

Any comments, links or PDF's (for tankless installs in general) would be greatly appreciated.

Direct vent with PVC. At least thats what the link says.
Quietside ODW-199A 7.2 GPM Tankless Water Heater 91% - 199,000 BTU

Originally Posted by Vern Heiler

Direct vent with PVC. At least thats what the link says.
Quietside ODW-199A 7.2 GPM Tankless Water Heater 91% - 199,000 BTU

Since the flue gas temperature is about 130°F you can use a Schedule 40 PVC for flue and intake piping. Up to 45 equivalent Feet of 3" or 4" venting with a maximum of 3 elbows can be used to vent the ODWs.

That answers that question, thanks Vern.

Originally Posted by chris mcintyre

Scott,

Pex is wrong?, I'm embarrassed to ask, but how?

.

I was looking specifically for venting, which my be why I couldn't find anything, (it was obviously not lack of internet skills ), if you could post them that would be great!

Here are the only other pictures I have,

The PEX is not supported properly , see the bow in the long run before it turns and goes through the floor. Then at the floor it is sealed with some type of goop. PEX lines move as it heats, cools and when the water is turned on and off. It needs to be able to move and can not be taught or fixed in place like that.

When the PEX is not supported properly it will stress the connectors, and you can have failure or leakage at those points. Same goes for when the PEX is not allowed to move. The ideal install will use as few joints/connectors as possible and then connect to a manifold for each fixture in the home. If they had not used all of the connectors and have used a single piece of PEX, then the support problem would have been easier to fix.

Rinani requires a condensate drain on the exhaust flue if the the flue exceeds a certain length or a negative slope back towards the unit. The condensate drain must have a full loop full of water commonly made of clear tubing.

Number of other questionable installation issues. Get you some install guides for that unit.

Originally Posted by Bruce Ramsey

Number of other questionable installation issues. Get you some install guides for that unit.

O.K., I did find the installation manual in a corner, in the attic. After looking through it (and from Vern's post) I realized that this a direct vent unit, the installers are trying to vent through the roof. There is no mention of this being allowed.

The website on the manual is Quietside, I could not find anything on the water heaters. Maybe they are new, or could be my computer, but nothing! I have e-mailed them and will see what they say.

It is frustrating when you piss away half a day (so far) trying to save the homeowner from having to buy 2 new tankless water heaters that is the fault of an incompetent sub.

I just clicked on the link in my post and went straight to it! I don't why it works that way, but cool!

Well if anyone wants to take a look and give me your thoughts on the vent through roof thing the model # is OWD-199A

http://www.quietside.com/images/Quietside/Products/ODW/171-174/ODW_manual%20Final%20Print%201st%20Production.pdf

Well if anyone wants to take a look and give me your thoughts on the vent through roof thing the model # is OWD-199A

I went to the venting section. It says not to install the vent vertically in- line ( I think that means with no offsets). I don't get what that means for sure though. I'd recommend e- mailing the manufacturer to determine whether or not it can vent through the roof.

Chris, I checked out the Quietside link also. After going to "Products" link, then to "Quietside on demand" link found mfg. info stating that the schedule 40 pvc venting can be vented vertically or sidewall. So, providing that the termination is per mfg requirements, through the roof should be fine.

Chris, found the installation instructions from your link. I would agree with Brandon that no inline verticall venting would mean a vertical vent run without elbows would not be allowed. 90+ furnaces with schedule 40 pvc venting usually require a minimum of 5' of vent with at least 1 elbow. This keeps the condensate water from blowing out the vent onto the roof. Would assume this would be the same. Brandon's suggestion to e-mail the mfg. sounds like a good idea since the instructions don't specifically show the c/a and venting as it is done.

From post #13:

I have e-mailed them and will see what they say.

Thanks guys, I will post what they send me.

also looks like electrical junction box in back ground needs a cover

Originally Posted by chris mcintyre

Thanks guys, I will post what they send me.

They sent me a "technical bulletin to provide information not contained in the previously literature" that allows for the intake air to come from the attic and the exhaust to vent through the roof.

What I have learned is that there is no standard when it comes to tankless water heaters, every manufacture is vastly different.

Scott, I almost forgot, told the plumber there were some issues with the water lines, he called and said he could not believe his guys left it that way , and they will take care of it Tuesday when they come back to finish up. Thanks for the help.

Couple o' things about the venting -- First, in the picture of the vents, look at the pipe closest to us, and the final verticle run -- looks shot in that 90 at a pretty horrible angle. Is it glued well?

Second -- The pipe behind, how it looks like it's sloped the wrong way -- some heaters require that so condensation can't roll back into the heater, BUT -- they also require a little drain coming off it curled like a pig's tail to form a crude trap so the condensation can drain properly.

I know that PEX piping on a tank water heater has to be 18 inches from unit, does this apply to tankless heater as well?

Read the section on water quality (hardness).

Warranty can be void if not addressed.

Filtration is recommended by most manufacturers... at minimum small filter by the unit.

Routine cleaning required; there does appear to be access fittings at inlet / outlet.

Flush with water and vinegar

Circulating pumps add another dimension of do's / dont's

I would be concerned with the pitch of the vent. It appears to be pitched inward, this will cause rainwater to collect, ice may form and prevent the vent from properly operating...

The vent piping needs to have a condensate drain installed. AS it is piped now, the condensate will build up at the 90º elbows and start to restrict the flow of combustion air. The condensate drain also needs to be properly trapped and disposed of.

That install would be OK if the vents terminated out of the side of the house this way the condensation would just drain off.

Also noted in the installation instructions that they want you to slope the intake pipe 1 in 10" or 1 in 12" down towards the termination and slop the exhaust pipe at 1 in 10" or 1 in 12" up towards the termination but the instructions read more for horizontal installations.