Trouble shooting Waterflow Lines / Problems


  #1  
Old 01-18-06, 07:32 AM
O
Member
Thread Starter
Join Date: Oct 2004
Posts: 26
Upvotes: 0
Received 0 Upvotes on 0 Posts
Trouble shooting Waterflow Lines / Problems

We have successfully installed a new Takagi Tankless water heater

but, ran into some hot waterflow trouble shooting concerns

The Tankless waterheater has been preset at the factory to 122 degrees
The current hot water flow is warm at its best.

The Installation Manual recommends that we look for the following common trouble shooting issues;

1. Mixing Valves (what is this and how do you locate the problem)

2. Thermostatic valvle (what is this and how do you locate the problem)

3. Single handled faucets with built in temperature or pressure compensators
valves (what is this and how do you locate the problem)

4. Hot and Cold crossed connections (what is this and how do you locate the
problem

This morning showers were warm at best, and my wife wants to know why with the traditional 50 gallon water heater (which was on its last leg) did not
have a problem with putting out HOT Water, just not enough for a family of
5

Any insight on these trouble shooting concerns will be appreciated
 
  #2  
Old 01-18-06, 08:02 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,725
Upvotes: 0
Received 1 Upvote on 1 Post
Issues 1, 2, and 3 would have been problems with the old system as well.

The most likely in issue is #4 - right at your new heater.
Are you positive that you connected the cold water to the inlet side?

Is your heater electric?
If so, is it getting the correct voltage?
If you are running it at 120V instead of 240V, that would be the problem.

Is your heater gas?
If you are feeding it through 3/8" tubing or have a blockage in the line or otherwise incorrect pressure during operation, that could be the problem.
You need to verify the pressure at the unit during operation.
 
  #3  
Old 01-18-06, 08:30 AM
O
Member
Thread Starter
Join Date: Oct 2004
Posts: 26
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thank for the reply

The Takagi Tankless waterheater is 190 BTU unit

We ran a 1 inch dedicated gas line from the home gas meter, which is a 175 gas meter to the Takagi Tankless waterheater.

According to my local PGE their 175 gas meter can handle upto 400 BTU.

We checked the Hot and Cold connections and no lines are mixed up

I will be calling PGE today to re-confirm the meter capacity

One other item, when the installer was checking the water lines, he asked me to turn on the HOT Water on different faucets through out the house. The result was cold water coming from the hot side. That really troubled the installer as he indicated that NO Water even cold water should have been running. What was the installer trouble shooting?

Thanks again for the reply. This has been a long time planning project and its
HURTS to run into this roadblock
 

Last edited by onetime; 01-18-06 at 08:45 AM.
  #4  
Old 01-18-06, 08:41 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,725
Upvotes: 0
Received 1 Upvote on 1 Post
What happens if you raise the thermostat setting to maximum?

(I doubt that your home gas meter is the problem.
Only a pressure check on the gas line at the heater during operation can tell you whether there is a pressure problem.)

Is the cold water inlet temperature unusually cold?
 
  #5  
Old 01-18-06, 08:46 AM
O
Member
Thread Starter
Join Date: Oct 2004
Posts: 26
Upvotes: 0
Received 0 Upvotes on 0 Posts
One other item, when the installer was checking the water lines, he asked me to turn on the HOT Water on different faucets through out the house. The result was cold water coming from the hot side. That really troubled the installer as he indicated that NO Water even cold water should have been running. What was the installer trouble shooting?
 
  #6  
Old 01-18-06, 09:05 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,725
Upvotes: 0
Received 1 Upvote on 1 Post
Originally Posted by onetime
One other item, when the installer was checking the water lines, he asked me to turn on the HOT Water on different faucets through out the house. The result was cold water coming from the hot side. That really troubled the installer as he indicated that NO Water even cold water should have been running. What was the installer troubleshooting?
This is back to issues 1 and 2.

Is this unit installed somewhere other than where the old water heater tank was connected?
 
  #7  
Old 01-18-06, 09:17 AM
O
Member
Thread Starter
Join Date: Oct 2004
Posts: 26
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes, It went from a uility room on the 2nd floor to the attic directly above the utility room. Copper lines were extended and rerouted to the Tankless Unit

I spoke with the Tagaki Rep about 20 min ago and he version was I have cold water crossing into the hot lines which is causing the water from reaching its HOT temperture.

I also spoke with a local plumbing shop which indicated it could be my single hanlded shower (pull out and twist type) faucets. I will try this adjustments and hopefully it will work

if not, its looks like I might be cooking my for myself until I fix the problem

again thanks for the communication,
 
  #8  
Old 01-18-06, 09:39 AM
bolide's Avatar
Member
Join Date: Jan 2006
Location: PA
Posts: 1,725
Upvotes: 0
Received 1 Upvote on 1 Post
Arrow

Originally Posted by onetime
Yes, It went from a uility room on the 2nd floor to the attic directly above the utility room. Copper lines were extended and rerouted to the Tankless Unit.

I spoke with the Tagaki Rep about 20 min ago and his version was I have cold water crossing into the hot lines which is causing the water from reaching its HOT temperture.
I agree with him. Perhaps the extra elevation changed the pressure balance in the system so wherever the hot-cold crossover is, it has tipped the balance more toward the cold.

Don't forget to check laundry hook-ups and any where else that hot and cold could be mixing. (The faulty fixture could be the only one that actually gets hot when it is the only one turned on.)

Test 1:
Try turning off as many cold water valves as possible (under sinks, behind the clothes washer, etc. - anything that does not feed the heater). Then see whether you can get hot water anywhere.
If you do not, you need more isolation valves to continue diagnosis.

Test 2:
Shut off the cold water inlet to the heater. You should not get water pressure (other than what drains from the line by gravity) from any fixture that is turned on hot only.

If you do, you have to locate the source of the crossover. Otherwise, one by one, turn on the cold water valves that were shut off for test 1. At some point the water will start flowing cold again. Turn off the salt valve opened and verify that water returns to being hot.

I am trusting that the pipes were extended from exactly where the old heater was connected.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: