New Tankless water heater install on 400 amp service


  #1  
Old 09-07-14, 09:13 PM
M
Member
Thread Starter
Join Date: Apr 2013
Posts: 10
Upvotes: 0
Received 0 Upvotes on 0 Posts
New Tankless water heater install on 400 amp service

I picked up a Ecosmart 27 Tankless heater to replace our aging 50gallon hot water heater.

We have a two bath home and groundwater is 57 degrees, so it should fit our needs. Our biggest problem with a family of six is running out of hot water

My question is which panel would be the smart choice to install?

The first panel is 200 amps and covers the house (stove, dishwasher, dryer, washing machine, current water heater, lights, plugs) It still has room for the three 40 amp breakers required for the tankless heater, but then would leave only 2 open slots when done.

The second panel is 200 amps and runs a 4 ton heat pump for down stairs (100 amp breaker) and a 2 ton split unit for upstairs (a 60 amp to outside and a 30 amp inside breaker) and has plenty of space left in the box.

TIA
 
  #2  
Old 09-07-14, 09:33 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,648
Received 3,898 Upvotes on 3,494 Posts
Do you have 2) two hundred amp breakers at your meter location that supplies each panel ?

It would appear that the second panel has a lot of load on it. You should do a load calculation for the second panel. Go to each connected device and read the amperage requirement. Add them up for a total.
 
  #3  
Old 09-08-14, 05:22 AM
M
Member
Thread Starter
Join Date: Apr 2013
Posts: 10
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes, both panels are 200 amp breakers.

The second panel only has the two units, both manufactured in 2013 and installed in 2014.

The acutal running amps of the 4 ton should be around 20 amps and 2 ton around 15, the kicker is the start up load on the 4 ton is listed at 100 amps nd the 2 ton at 50.

I was afraid you were going ot say measure the amps, and my dang clamp meter is broker (the joys of have a 3 year old)
 
  #4  
Old 09-08-14, 05:44 AM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 13,974
Received 194 Upvotes on 170 Posts
I would look at adding the tankless to the HVAC panel. While the startup loads are high the run loads are low leaving more capacity for the WH.
 
  #5  
Old 09-08-14, 12:17 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 9,870
Received 185 Upvotes on 166 Posts
a 4 ton heat pump for down stairs (100 amp breaker) and a 2 ton split unit for upstairs (a 60 amp to outside and a 30 amp inside breaker)
The acutal running amps of the 4 ton should be around 20 amps and 2 ton around 15, the kicker is the start up load on the 4 ton is listed at 100 amps nd the 2 ton at 50.
I would also use the second HVAC panel for the new loads, but while considering the loads, I'd also look into the proper Maximum Overcurrent Protection ampacity for each of the outside units. This might be listed on the data plate of each unit. The breakers appear to me to be well above what they should be. My thought is the 4 ton heat pump should probably be on no larger than a 40 amp breaker (rather than 100 amp breaker) and the 2 ton condensing unit should be on no larger than a 30 amp breaker (rather than 60 amp breaker).
 
  #6  
Old 09-08-14, 02:26 PM
M
Member
Thread Starter
Join Date: Apr 2013
Posts: 10
Upvotes: 0
Received 0 Upvotes on 0 Posts
I thought the breakers were a little overkill after looking at the units. I think what happened is both units were 30 years old and failed 6 months apart and the hvac guy just used existing panels from the old install instead of replacing breakers with more appropriate sizes. I haven't done any electrical work in 20 years since my uncle passed so wanted to make sure I wasn't missing something when I looked at the second panel.

Thanks for all your help and advice.
 
  #7  
Old 09-08-14, 02:37 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 29,711
Upvotes: 0
Received 15 Upvotes on 13 Posts
Not the question you asked but have you read any of the threads on tankless water heaters over in plumbing. General consensuses seems to be they aren't worth the extra cost.
 
  #8  
Old 09-08-14, 04:08 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 15,988
Received 84 Upvotes on 76 Posts
Not the question you asked but have you read any of the threads on tankless water heaters over in plumbing. General consensuses seems to be they aren't worth the extra cost.
Our biggest problem with a family of six is running out of hot water
Other then space this is the main reason for going tankless..

The units I have service here in NJ have 3 - 40 amp elements.. They work well for being electric...
These are usually installed on the island ( LBI) where there is no fuel source and the summer bungalows have no room for tank heaters....

I dont know anything about the eco smart units in regards to quality...
 
  #9  
Old 09-08-14, 04:15 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 13,974
Received 194 Upvotes on 170 Posts
Your HVAC units will have dataplates on them with both the minimum circuit ampacity and maximum overcurrent protection size.

Side note: A two pole 30 amp breaker is a 30 amp breaker, not a 60. I do not know if someone was adding the pole ratings together when you stated the breaker sizes.
 
  #10  
Old 09-08-14, 05:57 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 64,648
Received 3,898 Upvotes on 3,494 Posts
Keep in mind that the heatpumps probably have re-heat coils and they may possibly be included in those larger breaker sizes.
 
  #11  
Old 09-08-14, 07:22 PM
M
Member
Thread Starter
Join Date: Apr 2013
Posts: 10
Upvotes: 0
Received 0 Upvotes on 0 Posts
I called the HVAC guy and the 4ton is 100 amp due to the coils, the 2ton split is 40 and 30. We have several tankless installs in the area, some 3 years old, and have worked out well. The key is groundwater temp and gpm. For me, I picked up the tankless on sale for $200 and cost of wire and breakers added a little over a hundred more, so cheaper than another 50 gallon tank. The ecosmart had great reviews on amazon and homedepot. Figured worse case, if it doesn't work out I can always go back to the traditional water heater.
 
  #12  
Old 09-08-14, 08:20 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 9,870
Received 185 Upvotes on 166 Posts
I called the HVAC guy and the 4ton is 100 amp due to the coil
I could believe the 100 amp breaker was necessary if the 100 amp circuit powers both the outside unit AND the airhandler, where the electric resistance elements would be located. Just the heat pump outside your house would not need a 100 amp circuit.
 
 

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