Drill Hole In Conentric Vent For Tankless Water Heater? - HVAC - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 01-07-2014, 10:28 AM   #1
Member
 
Join Date: Oct 2008
Location: Albany, NY
Posts: 76
Rewards Points: 83
Default

Drill hole in conentric vent for tankless water heater?


I have a recently installed Rinnai RU801 Tankless Water Heater. The WH was installed with the concentric vent option. The WH is mounted on an interior wall, and the vent goes directly to a 90 degree elbow, then slopes UP to the exterior wall over about a 10 foot distance, then 90s up, second 90 to horizontal, exits the house, then 90s up in a snorkel for about 18" (for snow), then 90's horizontal with the dual pipe outlet/inlet.

The house is still under construction, and the WH has not yet been fired up yet.

I've had some intermittent water drips that appeared on the bottom of the water heater, but I was not able to determine the source. Yesterday, there was a lot of water on the ground, and I took off the cover and traced the water up to the intake fan. It appears that water is entering the intake air pipe and running down to the tankless water heater (I thought it was wrong to slope DOWN to the water heater, but the instructions indicated that this is how to do it).

I've read the WH manual, and while it addresses condensate from the exhaust, it says nothing about the intake.

I can try to better protect the intake from rain, but is there anything I can do on the intake pipe? Can I drill a hole in the exhaust section of the pipe and run it to a drain?

Advertisement

toddmanqa is offline   Reply With Quote
Old 01-07-2014, 10:40 AM   #2
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 14,980
Rewards Points: 602
Default


you cannot drill any drain holes for safety reasons. sounds like the pipe is sweating and may need to be insulated. not uncommon in cold climates. post some pics of the venting and heater. if the heater was running then some heat from it may keep the pipe warm enough to prevent sweating.

Advertisement

__________________
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote
The Following User Says Thank You to yuri For This Useful Post:
plummen (01-08-2014)
Old 01-07-2014, 07:15 PM   #3
An old Tradesmen
 
Join Date: Oct 2008
Location: Somewhere
Posts: 33,261
Rewards Points: 5,488
Default


Post pic of concentric. It may be installed incorrectly.
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 01-08-2014, 08:20 AM   #4
Member
 
Join Date: Oct 2008
Location: Albany, NY
Posts: 76
Rewards Points: 83
Default

pictures as requested


Pictures are attached
Attached Thumbnails
Drill hole in conentric vent for tankless water heater?-img_2038-smaller.jpg   Drill hole in conentric vent for tankless water heater?-img_2043-smaller.jpg   Drill hole in conentric vent for tankless water heater?-img_2042-smaller.jpg   Drill hole in conentric vent for tankless water heater?-img_2047-smaller.jpg  
toddmanqa is offline   Reply With Quote
Old 01-09-2014, 05:39 AM   #5
An old Tradesmen
 
Join Date: Oct 2008
Location: Somewhere
Posts: 33,261
Rewards Points: 5,488
Default


Looks right.

I would have the installer contact Rannai to see if they okay tapping a drain into the intake.
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 01-09-2014, 10:51 AM   #6
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 14,980
Rewards Points: 602
Default


or try stuff fibreglass pink insulation around the pipe where it enters inside the house for a couple of feet temporarily until the heater is fired up. I think you are getting cold conduction down the pipe from outside causing sweating. may go away once it is fired up and there is heat in there. we insulate the first 3-6 feet of our intake pipe in my area if they sweat. you can leave the insulation in the joist space permanently. You are going to have a SERIOUS problem later if you don't keep all that snow away from the pipes. the exhaust will recirc into the intake and the moisture will destroy the burner from corrosion etc and it won't burn properly or safely. It needs to be 3 feet above the max snow level or relocated to a non snow area.
__________________
"Cut it twice and it is still too short".

Last edited by yuri; 01-09-2014 at 11:29 AM.
yuri is online now   Reply With Quote
Old 01-09-2014, 12:13 PM   #7
Member
 
Join Date: Dec 2006
Posts: 17,158
Rewards Points: 6,652
Default


Your piping is sweating, due to it is warmer inside, then the surface of the pipe. I just had that issue with the intake on our furnace. Placing two 1500 watt heaters in my basement, solved that issue real quick. No more moisture dripping off of the PVC piping.
gregzoll is offline   Reply With Quote
Old 01-09-2014, 12:49 PM   #8
Hvac Pro
 
yuri's Avatar
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 14,980
Rewards Points: 602
Default


expensive way to get rid of sweating though. usually if you insulate the intake about 6 feet then the air warms up enough and it does not sweat.

Advertisement

__________________
"Cut it twice and it is still too short".
yuri is online now   Reply With Quote
Reply

Tags
concentric , leak , rinnai , tankless , water heater


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Chasing Ghosts - Phantom Water Leak FrozenMeatballs Plumbing 7 10-29-2014 07:03 PM
direct vent water heater location BlueBSH HVAC 7 12-17-2012 02:20 PM
elevate electric water heater? crankbait09 Plumbing 18 04-18-2011 12:35 PM
Broken caliper bolt chrissyb Automotive Repairs 12 12-28-2009 04:18 PM
(Water Heater MYSTERY) Hot water out from dead tank with cold water in it? Inayity Plumbing 6 07-14-2008 09:36 PM




Top of Page | View New Posts

 

Search Engine Friendly URLs by vBSEO 3.6.1