tankless-luke warm shower

wt · 01-30-2009, 08:59 AM

I recently installed a tankless hot water heater. I have a shower panel with a single handle adjustment with a mixing valve. The only way I can get the shower hot is by restricting flow at the gate valve on the cold supply line. I have adjusted the shower anti scald valve all the way to its hottest setting. All other fixtures in house will produce hot water. I did notice in a second bathroom that has an older valve setup that when only the hot water is turned on all the way that the flow is not as strong as it used to be prior to hooking up the tankless unit. It does come out hot but the flow rate is less than if you turn on only the cold side. Could the imbalance in flow rate at the mixing valve be the reason for not getting a hot shower? Can I put a circulation pump on the hot line to increase the pressure to match that of the cold line? Do I put the pump after the tankless unit or before it? Thanks for your help.

Water pipe sizing

**Dunbar Plumbing** · 01-30-2009, 09:18 AM

Sounds like an undersized unit.

No fixes for that.

You're exceeding the demand that tankless will provide.

Use a water saver showerhead.

Did you buy the bosch from lowe's/home depot?

**jadnashua** · 01-30-2009, 09:28 AM

Almost all tankless systems have a flow restrictor in them. So, not seeing as much volume in the hot side verses the unrestricted cold side is entirely normal. I do not know for sure, but wouldn't be surprised that the valve will not allow all hot input, and because the cold is full flow, you may never get hot enough. The pressure balance function may be restricting the hot flow.

**Ladiesman271** · 01-30-2009, 09:30 AM

To get an informed answer first make sure that your heater is perfoming right.

1. Measure the temperature of the hot water at the sink closest to the shower after the hot water has run for a while.

2. Measure the temperature of the cold water at the sink closest to the shower after the cold water has run for a while.

3. Measure how many gallons per minute you get from your shower head with your normal settings.

The make and model number and type (gas/electric) of the tankless is also needed.

**nhmaster** · 01-30-2009, 12:44 PM

Ain't tankless heaters great?

Note the number of threads about tankless problems compared to threads about tank water heater problems.

**Gary Swart** · 01-30-2009, 02:24 PM

I wondered how long you could keep quite on this one.

Gotta love tankless. Without them and Whirlpool WHs it would be lonesome.

**nhmaster** · 01-30-2009, 03:08 PM

I had a nightmare last night. House piped in CPV and ABS with a tankless water heater, Champion toilets and Moen valves throughout. AHHHHHHHHHHH.

**master plumber mark** · 02-01-2009, 01:04 PM

Delta faucets have been in so much controversy
due to the tankless water heaters that they are now
sending out a disclaimor in every box telling
the customer that a pressure balanced faucet
and a tankelss water do not work well together....

they empahtically state that this is not their
faucets problem, it is the gap and hesitation
in the tankless heater that causes the trouble..

their pressure balanced faucet is
doing what it was intended to do
so piss off.

gee, I wonder if that is what is going on here>>>

..

**gregsauls** · 02-01-2009, 06:00 PM

Originally Posted by master plumber mark

Delta faucets have been in so much controversy
due to the tankless water heaters that they are now
sending out a disclaimor in every box telling
the customer that a pressure balanced faucet
and a tankelss water do not work well together....

they empahtically state that this is not their
faucets problem, it is the gap and hesitation
in the tankless heater that causes the trouble..

their pressure balanced faucet is
doing what it was intended to do
so piss off.

gee, I wonder if that is what is going on here>>>

..

Got one of each... they work well together for me and my family of six.... But then again I installed both!

Water pipe sizing

**Dunbar Plumbing** · 02-01-2009, 07:32 PM

Originally Posted by master plumber mark

Delta faucets have been in so much controversy

Originally Posted by master plumber mark

due to the tankless water heaters that they are now
sending out a disclaimor in every box telling
the customer that a pressure balanced faucet
and a tankelss water do not work well together....

they empahtically state that this is not their
faucets problem, it is the gap and hesitation
in the tankless heater that causes the trouble..

their pressure balanced faucet is
doing what it was intended to do
so piss off.

gee, I wonder if that is what is going on here>>>

..

I missed this....so is Delta putting this in their boxes, or the tankless heaters?

I never read the instructions on anything; I learn more by trying to figure it out on my own.

I just bought a kidney from india and I think it's working. I'm pissing blood but that's normal for the first 96 hours!

**sjsmithjr** · 02-02-2009, 04:00 AM

Well, it's on the Delta website:

"Often the outgoing water pressure from a "tankless" water heater is relatively low. As a result, these devices are not generally recommended for use with pressure balanced units due to the possible differences in water pressure from the hot and cold lines. For example, if you were to have 20 PSI on the hot supply line and 50 PSI on the cold, since pressure balancing adjusts to the low pressure, your resulting operating pressure in the shower will be reduced."

Maybe Greg should give Delta a call and let them know that their wrong too. The Boy Scout's all trades certified and got it all figured out, you know.

**gregsauls** · 02-02-2009, 05:38 AM

Originally Posted by sjsmithjr

Well, it's on the Delta website:

"Often the outgoing water pressure from a "tankless" water heater is relatively low. As a result, these devices are not generally recommended for use with pressure balanced units due to the possible differences in water pressure from the hot and cold lines. For example, if you were to have 20 PSI on the hot supply line and 50 PSI on the cold, since pressure balancing adjusts to the low pressure, your resulting operating pressure in the shower will be reduced."

Maybe Greg should give Delta a call and let them know that their wrong too. The Boy Scout's all trades certified and got it all figured out, you know.

Sure, they can call me! Delta can even come out and check what I have. It works and YOU can't take that fact away! HAHA. The key to a tankless system being trouble free is proper sizing of the unit in the first place. Buy too small a unit and you WILL have problems. Installation issues is the second area of problems. Wrong gas line sizing, wrong water pipe sizing and tankless location will cause problems too. The third area of issues is region... too cold inlet water temp, too low water pressure and just plain too cold of region can all cause problems.

Selling, installing, and using a tankless system requires some brain power! Don't be dissin' a Boy Scout....

**sjsmithjr** · 02-02-2009, 06:53 AM

I see. So the blind squirrel gets a nut and things like working in your field for over 20 years, extensive experience, the ability to troubleshoot multiple systems, etc. etc. goes out the window.

Why wait to be discovered? I really think you should give Delta a call and explain to them the error of their ways. Why stop there, though? HD and Lowes are obviously in need of schooling as well. Sounds to me like your sitting on a gold mine!

**Redwood** · 02-02-2009, 07:33 AM

Here greg just so you have the benefit of seeing it with your own eyes...

Are "tankless" water heaters recommended?

Often the outgoing water pressure from a "tankless" water heater is relatively low. As a result, these devices are not generally recommended for use with pressure balanced units due to the possible differences in water pressure from the hot and cold lines. For example, if you were to have 20 PSI on the hot supply line and 50 PSI on the cold, since pressure balancing adjusts to the low pressure, your resulting operating pressure in the shower will be reduced.

http://www.deltafaucet.com/customers...ater+Pressure/

Perhaps you need to realize that your tankless experience down in Texas is going to be a lot more pleasant than a person might have in Houlton, Maine where they might be looking at an 87 Degrees F rate of rise spec and wondering when some water is going to start coming out of their pressure balanced shower.

To ignore that is simply having a vision problem...

**Redwood** · 02-02-2009, 07:37 AM

Originally Posted by gregsauls

Hmmm, your words not mine. But if the shoe fits....

You know what probably would help this forum, this board and the people posting real world questions? Put a post up for all the tankless bashing to take place so all the die hard folks can whale away on. Then lets leave all the new posts for people who have questions about issues, large or small, to valid answer and not just another avenue for the pro/con wars that will do the end user no good!

Time for a truce folks. Otherwise I see no end to this stupidity! Can you do it is the question?

Is tankless performance outside of the extreme south of the country a real world question?

When you get away from there tankless loses its practicle and green appeal.
It becomes more a situation of I want my 20 GPM carwash shower to work and I want an unlimited supply of water for it!
I don't care what it costs!