Apologies if this isn't the right forum to post technical questions.  I had a contractor install a Panasonic dual zone outdoor condenser with just one indoor unit, unfortunately it's not functioning like he thought.  The supplier and contractor both thought the dual zone would work fine with one indoor unit, sadly the indoor unit is spewing error code H12 which means the outdoor unit didn't detect a min of 2 indoor units.  Does anyone know if there's a way to get around this error?  The contractor had install many 3 zone outdoor condensers with just two indoor units, hence there's no reason one unit on a dual zone unit won't work.

The outdoor model# is CU-2E18NBU and indoor is CS-E12NKUAW.

The idea behind having one indoor unit was to see how well it performs before adding a 2nd one.

Thanks.

When all else fails, read the manual. (See Remark # 1, bottom of page 6.)

It truly is remarkable what a manual can tell you.

"…hence there's no reason one unit on a dual zone unit won't work." Did your contractor tell you this?

Not poking fun at you bc, your contractor should have known this or at least have read the manual if he wasn't sure.

"The idea behind having one indoor unit was to see how well it performs before adding a 2nd one."

Not very well.
I don't know which to shake my head at more. That the installer didn't know his product or he chose to do an incremental installation.
I'm not criticizing you I just don't understand the mind set of the installer.

Seriously, it took me less than 3 minutes to find the manual online, and dig up the note referring to the two-heads only requirement. Even flipping through a paper manual the installers should have been able to find it in less than a half hour once they had it to the point where it was spitting out the error code.

An installer or supplier worth their salt would have known about it going in, and wouldn't even had to look up the error code. While it's pretty common for 3 zone systems to be able to run with only 2 heads, even that isn't universal. If they sold it to you under the presumption that it should be able to run with a single head, it's up to them to make it right, either by swapping in a 1.5 ton 2 zone mini-split that CAN operate single-headed, or cutting you an at-cost deal on a second head (assuming that would be an acceptable solution for you.) The think can take either any mix of 3/4 ton or 1 ton heads.

The number of components in the Panasonic ductless lineup is pretty limited compared to the endless array from Mitsubishi, (where head/compressor compatibility mismatches are all too commonly made by installers who can't read the manual. ) Chock this one up to installer (and distributor) training.

Most tradesmen I saw during my build were too experienced and knowledgeable to read the manual. The best ones asked to take the manual home to read or actually came to the install having read it and were able to discuss issues. The rest were more than willing to tell you that reading the manual offended them.

"...too experienced and knowledgeable." "....reading the manual offended them."

Exactly the type of guys I don't want to work with. I agree fully that the best guys are willing to read the manual and come back with comments or concerns. That's how something gets done correctly the first time.

Most tradesman have been installing their products for years. When changes are made to the product, or when selections must be made (such as dip switch settings on a PC board) I seldom remember all off the top of my head and turn to the manual.
If installing a new product or something in a new application for me the manual is the first stop.

As an inspector the manual is a defacto part of the code and I will seek them out often. Particularly on fireplaces where the code yeilds vent location completely to the manufacturer.

If a customer were to suggest I should look at the manual on a routine install, I don't know that offended would be the word, but they would leave with the distinct impression that "this ain't my first rodeo".

Frankly however I tend to have relationships of trust with my customers. They do not select products or applications I'm not familiar with, they accept my advice, so they have an appropiate expectation that I am already familiar with the manual.

Have I ever goofed and installed a product I thought was suitable only to find out later it was not? Yep.....and I paid to change it. One of the costs of doing buisness.

I would like to put in my 2 cents as a certified HVAC tech.

First of all, the installer and supplier should of known the difference than to match these two components together.But there is a few things wrong with this install:

1,well the out door unit and indoor unit are different capacities, the outdoor unit is a 18000btu(1.5 ton) unit and the indoor unit is a 12000bntu (1 ton) unit.

2,the outdoor unit is a multi zone unit (for multiple indoor units) and the indoor unit is a single zone unit. The single zone indoor units and multi zone indoor unit send a different electrical system back to the outdoor unit. you can install 2 multi zone indoor units on an outdoor unit that access ports for 3 indoor units because the 2 indoor units would be sending the correct signal to the outdoor unit and the third access port is just to add more capacity.

So in order to fix this you could do one of the following:

1, have the one indoor unit removed and put two 9000btu multizone indoor units installed (1.5tons)

2, have the outdoor unit removed and have it replaced with a single zone 12000btu outdoor unit.

depending on if the installer will cover the cost, (because this was mainly his fault) i would decide on which option i would go with.

if the installer is coving the cost, i would do option B. this is the more costly option because the outdoor unit is the majority of the cost of an install, but this will allow you to get what you where supposed to get in the beginning.

but if the installer will not cover the cost for fixing his mistake i would do option A, this is alot less costly (around $300 wholesale per indoor unit) and you will get 150% of the capacity that you originally anted.

I hope this was a help for you, and for the installer , if he didn't know this basic piece of information, i don't think he should be installing these systems.